TY  - JOUR
AU  - Gabrovska, Margarita
AU  - Ivanov, Ivan
AU  - Nikolova, Dimitrinka
AU  - Krstić, Jugoslav
AU  - Venezia, Anna Maria
AU  - Cri¸san, Dorel
AU  - Cri¸san, Maria
AU  - Tenchev, Krassimir
AU  - Idakiev, Vasko
AU  - Tabakova, Tatyana
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4810
AB  - Supported gold on co-precipitated nanosized NiAl layered double hydroxides (LDHs) was studied as an effective catalyst for medium-temperature water–gas shift (WGS) reaction, an industrial catalytic process traditionally applied for the reduction in the amount of CO in the synthesis gas and production of pure hydrogen. The motivation of the present study was to improve the performance of the Au/NiAl catalyst via modification by CeO2. An innovative approach for the direct deposition of ceria (1, 3 or 5 wt.%) on NiAl-LDH, based on the precipitation of Ce3+ ions with 1M NaOH, was developed. The proposed method allows us to obtain the CeO2 phase and to preserve the NiAl layered structure by avoiding the calcination treatment. The synthesis of Au-containing samples was performed through the deposition–precipitation method. The as-prepared and WGS-tested samples were characterized by X-ray powder diffraction, N2-physisorption and X-ray photoelectron spectroscopy in order to clarify the effects of Au and CeO2 loading on the structure, phase composition, textural and electronic properties and activity of the catalysts. The reduction behavior of the studied samples was evaluated by temperature-programmed reduction. The WGS performance of Au/NiAl catalysts was significantly affected by the addition of CeO2. A favorable role of ceria was revealed by comparison of CO conversion degree at 220◦C reached by 3 wt.% CeO2-modified and ceria-free Au/NiAl samples (98.8 and 83.4%, respectively). It can be stated that tuning the properties of Au/NiAl LDH via CeO2 addition offers catalysts with possibilities for practical application owing to innovative synthesis and improved WGS performance.
PB  - MDPI
T2  - Nanomaterials
T1  - Improved water–gas shift performance of Au/NiAl LDHs nanostructured catalysts via CeO2 addition
VL  - 11
IS  - 2
SP  - 366
DO  - 10.3390/nano11020366
ER  - 

@article{
author = "Gabrovska, Margarita and Ivanov, Ivan and Nikolova, Dimitrinka and Krstić, Jugoslav and Venezia, Anna Maria and Cri¸san, Dorel and Cri¸san, Maria and Tenchev, Krassimir and Idakiev, Vasko and Tabakova, Tatyana",
year = "2021",
abstract = "Supported gold on co-precipitated nanosized NiAl layered double hydroxides (LDHs) was studied as an effective catalyst for medium-temperature water–gas shift (WGS) reaction, an industrial catalytic process traditionally applied for the reduction in the amount of CO in the synthesis gas and production of pure hydrogen. The motivation of the present study was to improve the performance of the Au/NiAl catalyst via modification by CeO2. An innovative approach for the direct deposition of ceria (1, 3 or 5 wt.%) on NiAl-LDH, based on the precipitation of Ce3+ ions with 1M NaOH, was developed. The proposed method allows us to obtain the CeO2 phase and to preserve the NiAl layered structure by avoiding the calcination treatment. The synthesis of Au-containing samples was performed through the deposition–precipitation method. The as-prepared and WGS-tested samples were characterized by X-ray powder diffraction, N2-physisorption and X-ray photoelectron spectroscopy in order to clarify the effects of Au and CeO2 loading on the structure, phase composition, textural and electronic properties and activity of the catalysts. The reduction behavior of the studied samples was evaluated by temperature-programmed reduction. The WGS performance of Au/NiAl catalysts was significantly affected by the addition of CeO2. A favorable role of ceria was revealed by comparison of CO conversion degree at 220◦C reached by 3 wt.% CeO2-modified and ceria-free Au/NiAl samples (98.8 and 83.4%, respectively). It can be stated that tuning the properties of Au/NiAl LDH via CeO2 addition offers catalysts with possibilities for practical application owing to innovative synthesis and improved WGS performance.",
publisher = "MDPI",
journal = "Nanomaterials",
title = "Improved water–gas shift performance of Au/NiAl LDHs nanostructured catalysts via CeO2 addition",
volume = "11",
number = "2",
pages = "366",
doi = "10.3390/nano11020366"
}

Gabrovska, M., Ivanov, I., Nikolova, D., Krstić, J., Venezia, A. M., Cri¸san, D., Cri¸san, M., Tenchev, K., Idakiev, V.,& Tabakova, T.. (2021). Improved water–gas shift performance of Au/NiAl LDHs nanostructured catalysts via CeO2 addition. in Nanomaterials
MDPI., 11(2), 366.
https://doi.org/10.3390/nano11020366

Gabrovska M, Ivanov I, Nikolova D, Krstić J, Venezia AM, Cri¸san D, Cri¸san M, Tenchev K, Idakiev V, Tabakova T. Improved water–gas shift performance of Au/NiAl LDHs nanostructured catalysts via CeO2 addition. in Nanomaterials. 2021;11(2):366.
doi:10.3390/nano11020366 .

Gabrovska, Margarita, Ivanov, Ivan, Nikolova, Dimitrinka, Krstić, Jugoslav, Venezia, Anna Maria, Cri¸san, Dorel, Cri¸san, Maria, Tenchev, Krassimir, Idakiev, Vasko, Tabakova, Tatyana, "Improved water–gas shift performance of Au/NiAl LDHs nanostructured catalysts via CeO2 addition" in Nanomaterials, 11, no. 2 (2021):366,
https://doi.org/10.3390/nano11020366 . .

TY  - CHAP
AU  - Stanković, Miroslav
AU  - Pavlović, Stefan
AU  - Marinković, Dalibor
AU  - Tišma, Marina
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3743
AB  - Coal fly ash (CFA) is generated during the combustion of coal for energy production. Many studies are based on its utilization as the most abundant, cheap
aluminosilicate industrial residue, which is recognized as a risk for the environment and human health. The present review is focused on CFA origin, chemical properties, and its catalytic application for biodiesel production. The aluminosilicate nature and the presence of rare earth elements make CFA suitable for different adsorption, catalytic, and extraction processes for obtaining valuable products including alternative fuels and pure elements. However, the presence of toxic elements is a potential environmental problem, which should be solved in order to avoid soil, water, and air pollution. The most used modification methods are alkali activation, hydrothermal, and thermal treatment that improve the structural, morphological, and textural properties. The active catalytic form could be obtained by impregnation or ion exchange method. It was found that such synthesized materials have significant catalytic potential in the biofuel chemistry. In the case of biodiesel production, the high values of conversion or yield can be achieved under mild low-energy reaction conditions in the presence of low-cost waste-based catalysts.
PB  - IntechOpen
T2  - Renewable Energy – Resources, Challenges and Applications
T1  - Solid green biodiesel catalysts derived from coal fly ash
SP  - 185
EP  - 208
DO  - 10.5772/intechopen.91703
ER  - 

@inbook{
author = "Stanković, Miroslav and Pavlović, Stefan and Marinković, Dalibor and Tišma, Marina and Gabrovska, Margarita and Nikolova, Dimitrinka",
year = "2020",
abstract = "Coal fly ash (CFA) is generated during the combustion of coal for energy production. Many studies are based on its utilization as the most abundant, cheap
aluminosilicate industrial residue, which is recognized as a risk for the environment and human health. The present review is focused on CFA origin, chemical properties, and its catalytic application for biodiesel production. The aluminosilicate nature and the presence of rare earth elements make CFA suitable for different adsorption, catalytic, and extraction processes for obtaining valuable products including alternative fuels and pure elements. However, the presence of toxic elements is a potential environmental problem, which should be solved in order to avoid soil, water, and air pollution. The most used modification methods are alkali activation, hydrothermal, and thermal treatment that improve the structural, morphological, and textural properties. The active catalytic form could be obtained by impregnation or ion exchange method. It was found that such synthesized materials have significant catalytic potential in the biofuel chemistry. In the case of biodiesel production, the high values of conversion or yield can be achieved under mild low-energy reaction conditions in the presence of low-cost waste-based catalysts.",
publisher = "IntechOpen",
journal = "Renewable Energy – Resources, Challenges and Applications",
booktitle = "Solid green biodiesel catalysts derived from coal fly ash",
pages = "185-208",
doi = "10.5772/intechopen.91703"
}

Stanković, M., Pavlović, S., Marinković, D., Tišma, M., Gabrovska, M.,& Nikolova, D.. (2020). Solid green biodiesel catalysts derived from coal fly ash. in Renewable Energy – Resources, Challenges and Applications
IntechOpen., 185-208.
https://doi.org/10.5772/intechopen.91703

Stanković M, Pavlović S, Marinković D, Tišma M, Gabrovska M, Nikolova D. Solid green biodiesel catalysts derived from coal fly ash. in Renewable Energy – Resources, Challenges and Applications. 2020;:185-208.
doi:10.5772/intechopen.91703 .

Stanković, Miroslav, Pavlović, Stefan, Marinković, Dalibor, Tišma, Marina, Gabrovska, Margarita, Nikolova, Dimitrinka, "Solid green biodiesel catalysts derived from coal fly ash" in Renewable Energy – Resources, Challenges and Applications (2020):185-208,
https://doi.org/10.5772/intechopen.91703 . .

TY  - CONF
AU  - Pavlović, Stefan
AU  - Marinković, Dalibor
AU  - Milovanović, Biljana
AU  - Kostić, Milan
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Stanković, Miroslav
PY  - 2019
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3434
AB  - Eggshell based catalysts were synthesized by calcination (600 and 900 ºC, 4 h) of raw and rehydration (RH) modified (RH-temperature of 80 ºC, S/L ratio of 1/5, and RH-time of 6 h) eggshell. After RH-treatment, the sample underwent calcination at 600 ºC, 4 h. Obtained catalysts were characterized by XRD, SEM, N2-physisorption, and Hg-porosimetry, whereas the catalytic activity was analyzed in a batch reactor (reaction temperature of 60 ºC, sunflower oil/methanol molar ratio of 1/12, and catalyst concentration of 4 wt.%). The concentration of fatty acid methyl esters (FAMEs) was determined by HPLC. The reaction has reached equilibrium (FAME > 97%) with rehydrated catalyst for 1.5 h, whereas with catalyst calcined at 900 ºC for 4 h.
PB  - DECHEMA e.V.
C3  - 14th EuropaCat – European Congress on Catalysis “Catalysis without Borders”
T1  - Effects of preparation conditions on the catalytic activity of chicken eggshell catalysts for the transesterification of oils to biodiesel
SP  - 643
EP  - 644
UR  - https://hdl.handle.net/21.15107/rcub_cer_3434
ER  - 

@conference{
author = "Pavlović, Stefan and Marinković, Dalibor and Milovanović, Biljana and Kostić, Milan and Gabrovska, Margarita and Nikolova, Dimitrinka and Stanković, Miroslav",
year = "2019",
abstract = "Eggshell based catalysts were synthesized by calcination (600 and 900 ºC, 4 h) of raw and rehydration (RH) modified (RH-temperature of 80 ºC, S/L ratio of 1/5, and RH-time of 6 h) eggshell. After RH-treatment, the sample underwent calcination at 600 ºC, 4 h. Obtained catalysts were characterized by XRD, SEM, N2-physisorption, and Hg-porosimetry, whereas the catalytic activity was analyzed in a batch reactor (reaction temperature of 60 ºC, sunflower oil/methanol molar ratio of 1/12, and catalyst concentration of 4 wt.%). The concentration of fatty acid methyl esters (FAMEs) was determined by HPLC. The reaction has reached equilibrium (FAME > 97%) with rehydrated catalyst for 1.5 h, whereas with catalyst calcined at 900 ºC for 4 h.",
publisher = "DECHEMA e.V.",
journal = "14th EuropaCat – European Congress on Catalysis “Catalysis without Borders”",
title = "Effects of preparation conditions on the catalytic activity of chicken eggshell catalysts for the transesterification of oils to biodiesel",
pages = "643-644",
url = "https://hdl.handle.net/21.15107/rcub_cer_3434"
}

Pavlović, S., Marinković, D., Milovanović, B., Kostić, M., Gabrovska, M., Nikolova, D.,& Stanković, M.. (2019). Effects of preparation conditions on the catalytic activity of chicken eggshell catalysts for the transesterification of oils to biodiesel. in 14th EuropaCat – European Congress on Catalysis “Catalysis without Borders”
DECHEMA e.V.., 643-644.
https://hdl.handle.net/21.15107/rcub_cer_3434

Pavlović S, Marinković D, Milovanović B, Kostić M, Gabrovska M, Nikolova D, Stanković M. Effects of preparation conditions on the catalytic activity of chicken eggshell catalysts for the transesterification of oils to biodiesel. in 14th EuropaCat – European Congress on Catalysis “Catalysis without Borders”. 2019;:643-644.
https://hdl.handle.net/21.15107/rcub_cer_3434 .

Pavlović, Stefan, Marinković, Dalibor, Milovanović, Biljana, Kostić, Milan, Gabrovska, Margarita, Nikolova, Dimitrinka, Stanković, Miroslav, "Effects of preparation conditions on the catalytic activity of chicken eggshell catalysts for the transesterification of oils to biodiesel" in 14th EuropaCat – European Congress on Catalysis “Catalysis without Borders” (2019):643-644,
https://hdl.handle.net/21.15107/rcub_cer_3434 .

TY  - CONF
AU  - Marinković, Dalibor
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Pavlović, Stefan
AU  - Milovanović, B.
AU  - Stanković, Miroslav
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2890
AB  - Lithium modified Mg/Al hydrotalcite-like samples with different Li content
were synthesized using co-precipitation followed by calcination at 500 °C.
The samples were characterized by means of XRD, DRIFTS, SEM-EDS,
LDPSA and MIP. Results from this study indicated that the addition of Li
modifier influences the change in structural, textural and morphological
characteristics, more pronounced in samples with higher lithium content.
PB  - Society of Physical Chemists of Serbia
PB  - Društvo fizikohemičara Srbije
C3  - Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry
T1  - Synthesis and characterization of mixed oxides derivate from Li modified Mg-Al hydrotalcites
VL  - 2
SP  - 657
EP  - 660
UR  - https://hdl.handle.net/21.15107/rcub_cer_2890
ER  - 

@conference{
author = "Marinković, Dalibor and Gabrovska, Margarita and Nikolova, Dimitrinka and Pavlović, Stefan and Milovanović, B. and Stanković, Miroslav",
year = "2018",
abstract = "Lithium modified Mg/Al hydrotalcite-like samples with different Li content
were synthesized using co-precipitation followed by calcination at 500 °C.
The samples were characterized by means of XRD, DRIFTS, SEM-EDS,
LDPSA and MIP. Results from this study indicated that the addition of Li
modifier influences the change in structural, textural and morphological
characteristics, more pronounced in samples with higher lithium content.",
publisher = "Society of Physical Chemists of Serbia, Društvo fizikohemičara Srbije",
journal = "Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry",
title = "Synthesis and characterization of mixed oxides derivate from Li modified Mg-Al hydrotalcites",
volume = "2",
pages = "657-660",
url = "https://hdl.handle.net/21.15107/rcub_cer_2890"
}

Marinković, D., Gabrovska, M., Nikolova, D., Pavlović, S., Milovanović, B.,& Stanković, M.. (2018). Synthesis and characterization of mixed oxides derivate from Li modified Mg-Al hydrotalcites. in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry
Society of Physical Chemists of Serbia., 2, 657-660.
https://hdl.handle.net/21.15107/rcub_cer_2890

Marinković D, Gabrovska M, Nikolova D, Pavlović S, Milovanović B, Stanković M. Synthesis and characterization of mixed oxides derivate from Li modified Mg-Al hydrotalcites. in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry. 2018;2:657-660.
https://hdl.handle.net/21.15107/rcub_cer_2890 .

Marinković, Dalibor, Gabrovska, Margarita, Nikolova, Dimitrinka, Pavlović, Stefan, Milovanović, B., Stanković, Miroslav, "Synthesis and characterization of mixed oxides derivate from Li modified Mg-Al hydrotalcites" in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, 2 (2018):657-660,
https://hdl.handle.net/21.15107/rcub_cer_2890 .

TY  - JOUR
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Krstić, Jugoslav
AU  - Lončarević, Davor
AU  - Tzvetkov, P.T.
AU  - Shopska, M.G.
AU  - Radonjić, Vojkan
AU  - Stanković, Miroslav
AU  - Jovanović, D.M.
AU  - Spasov, L.Т.
AU  - Simeonov, D.B.
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2390
AB  - Mg-doped co-precipitated Ni/SIG precursors were studied as edible sunflower oil hydrogenation catalysts applying two types of commercial silica gels (SIG) as supports of different texture characteristics: a microporous type (SIG-A) and a mesoporous type (SIG-C). It was found that texture parameters of both the silica gels and magnesium addition allow obtaining of catalysts of various hydrogenation activities and fatty acid composition of the products. The results reveal the highest hydrogenation activity of MgNi/SIG-C catalyst because of higher amount and accessibility of metal nickel particles on the catalyst surface generated through reduction procedure. A dominant activity of MgNi/SIG-C catalyst is ascribed to appropriate mesoporosity, which controls diffusion. It was established that Mg-doped Ni/SIG-C possessed a capacity for use as an efficient edible vegetable oil hydrogenation catalyst due to high hydrogenation activity, high saturation level of linoleic acid (C18:2cis), moderate amounts of C18:1trans fatty acids, and C18:0 stearin acid formation in the partially hydrogenated sunflower oil.
PB  - Bulgarian Academy of Sciences
T2  - Bulgarian Chemical Communications
T1  - Improved catalyst performance of Ni/SiO2 in vegetable oil hydrogenation: Impact of Mg dopant
VL  - 50
SP  - 161
EP  - 168
UR  - https://hdl.handle.net/21.15107/rcub_cer_2390
ER  - 

@article{
author = "Gabrovska, Margarita and Nikolova, Dimitrinka and Krstić, Jugoslav and Lončarević, Davor and Tzvetkov, P.T. and Shopska, M.G. and Radonjić, Vojkan and Stanković, Miroslav and Jovanović, D.M. and Spasov, L.Т. and Simeonov, D.B.",
year = "2018",
abstract = "Mg-doped co-precipitated Ni/SIG precursors were studied as edible sunflower oil hydrogenation catalysts applying two types of commercial silica gels (SIG) as supports of different texture characteristics: a microporous type (SIG-A) and a mesoporous type (SIG-C). It was found that texture parameters of both the silica gels and magnesium addition allow obtaining of catalysts of various hydrogenation activities and fatty acid composition of the products. The results reveal the highest hydrogenation activity of MgNi/SIG-C catalyst because of higher amount and accessibility of metal nickel particles on the catalyst surface generated through reduction procedure. A dominant activity of MgNi/SIG-C catalyst is ascribed to appropriate mesoporosity, which controls diffusion. It was established that Mg-doped Ni/SIG-C possessed a capacity for use as an efficient edible vegetable oil hydrogenation catalyst due to high hydrogenation activity, high saturation level of linoleic acid (C18:2cis), moderate amounts of C18:1trans fatty acids, and C18:0 stearin acid formation in the partially hydrogenated sunflower oil.",
publisher = "Bulgarian Academy of Sciences",
journal = "Bulgarian Chemical Communications",
title = "Improved catalyst performance of Ni/SiO2 in vegetable oil hydrogenation: Impact of Mg dopant",
volume = "50",
pages = "161-168",
url = "https://hdl.handle.net/21.15107/rcub_cer_2390"
}

Gabrovska, M., Nikolova, D., Krstić, J., Lončarević, D., Tzvetkov, P.T., Shopska, M.G., Radonjić, V., Stanković, M., Jovanović, D.M., Spasov, L.Т.,& Simeonov, D.B.. (2018). Improved catalyst performance of Ni/SiO2 in vegetable oil hydrogenation: Impact of Mg dopant. in Bulgarian Chemical Communications
Bulgarian Academy of Sciences., 50, 161-168.
https://hdl.handle.net/21.15107/rcub_cer_2390

Gabrovska M, Nikolova D, Krstić J, Lončarević D, Tzvetkov P, Shopska M, Radonjić V, Stanković M, Jovanović D, Spasov L, Simeonov D. Improved catalyst performance of Ni/SiO2 in vegetable oil hydrogenation: Impact of Mg dopant. in Bulgarian Chemical Communications. 2018;50:161-168.
https://hdl.handle.net/21.15107/rcub_cer_2390 .

Gabrovska, Margarita, Nikolova, Dimitrinka, Krstić, Jugoslav, Lončarević, Davor, Tzvetkov, P.T., Shopska, M.G., Radonjić, Vojkan, Stanković, Miroslav, Jovanović, D.M., Spasov, L.Т., Simeonov, D.B., "Improved catalyst performance of Ni/SiO2 in vegetable oil hydrogenation: Impact of Mg dopant" in Bulgarian Chemical Communications, 50 (2018):161-168,
https://hdl.handle.net/21.15107/rcub_cer_2390 .

TY  - CONF
AU  - Pavlović, Stefan
AU  - Kostić, Bojan
AU  - Marinković, Dalibor
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Lončarević, Davor
AU  - Stanković, Miroslav
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2889
AB  - Mg-Al hydrotalcites (Mg/Al molar ratio 3/1) doped with varying amounts of
lanthanum were prepared using co-precipitation followed by calcination in
order to study the effect of lanthanum on their structure and morphology.
Samples were characterized by several methods: XRD, FT-IR, SEM-EDS,
LDPSA and MIP. It was found that the addition of lanthanum affects the
structure and morphology of the obtained metal oxides derived from Ladoped
Mg-Al hydrotalcites, making it effective dopant for (Mg/Al/La)Otype
materials, being very promising for various catalytic reactions.
PB  - Society of Physical Chemists of Serbia
PB  - Društvo fizikohemičara Srbije
C3  - Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry (24-09-2018)
T1  - Structure and morphology of calcined lanthanum doped hydrotalcite
VL  - 2
SP  - 653
EP  - 656
UR  - https://hdl.handle.net/21.15107/rcub_cer_2889
ER  - 

@conference{
author = "Pavlović, Stefan and Kostić, Bojan and Marinković, Dalibor and Gabrovska, Margarita and Nikolova, Dimitrinka and Lončarević, Davor and Stanković, Miroslav",
year = "2018",
abstract = "Mg-Al hydrotalcites (Mg/Al molar ratio 3/1) doped with varying amounts of
lanthanum were prepared using co-precipitation followed by calcination in
order to study the effect of lanthanum on their structure and morphology.
Samples were characterized by several methods: XRD, FT-IR, SEM-EDS,
LDPSA and MIP. It was found that the addition of lanthanum affects the
structure and morphology of the obtained metal oxides derived from Ladoped
Mg-Al hydrotalcites, making it effective dopant for (Mg/Al/La)Otype
materials, being very promising for various catalytic reactions.",
publisher = "Society of Physical Chemists of Serbia, Društvo fizikohemičara Srbije",
journal = "Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry (24-09-2018)",
title = "Structure and morphology of calcined lanthanum doped hydrotalcite",
volume = "2",
pages = "653-656",
url = "https://hdl.handle.net/21.15107/rcub_cer_2889"
}

Pavlović, S., Kostić, B., Marinković, D., Gabrovska, M., Nikolova, D., Lončarević, D.,& Stanković, M.. (2018). Structure and morphology of calcined lanthanum doped hydrotalcite. in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry (24-09-2018)
Society of Physical Chemists of Serbia., 2, 653-656.
https://hdl.handle.net/21.15107/rcub_cer_2889

Pavlović S, Kostić B, Marinković D, Gabrovska M, Nikolova D, Lončarević D, Stanković M. Structure and morphology of calcined lanthanum doped hydrotalcite. in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry (24-09-2018). 2018;2:653-656.
https://hdl.handle.net/21.15107/rcub_cer_2889 .

Pavlović, Stefan, Kostić, Bojan, Marinković, Dalibor, Gabrovska, Margarita, Nikolova, Dimitrinka, Lončarević, Davor, Stanković, Miroslav, "Structure and morphology of calcined lanthanum doped hydrotalcite" in Physical Chemistry 2018 – 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry (24-09-2018), 2 (2018):653-656,
https://hdl.handle.net/21.15107/rcub_cer_2889 .

TY  - CONF
AU  - Stanković, Miroslav
AU  - Krstić, Jugoslav
AU  - Radonjić, Vojkan
AU  - Lončarević, Davor
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Pavlović, Stefan
PY  - 2016
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3817
AB  - Diatomite supported Ni-Mg catalyst precursors (Ni-Mg/D) with a constant Ni/Mg ratio, prepared by the precipitation-deposition method using different nickel salts, sulfamate, nitrate, chloride, acetate or formate, were studied by hydrogen chemisorptions and temperature programmed reduction (H2- TPR).The results showed that the dispersion of nickel and the reducibility of the prepared catalyst precursors were different depending upon the counter ion of the nickel salt. Among the studied nickel salts, the best results for the dispersion of metallic Ni and reducibility of Ni-Mg/D catalyst precursors were achieved using nickel sulfamate salt.
PB  - Belgrade :  Society of Physical Chemists of Serbia
C3  - Physical Chemistry 2016 (Proceedings) - 13th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade
T1  - Effect of Nickel Salts on the Dispersion of Nickel and Reducibility of Supported Ni-Mg Catalyst Precursors Prepared by Precipitation-Deposition
VL  - 1
SP  - 223
EP  - 226
UR  - https://hdl.handle.net/21.15107/rcub_cer_3817
ER  - 

@conference{
author = "Stanković, Miroslav and Krstić, Jugoslav and Radonjić, Vojkan and Lončarević, Davor and Gabrovska, Margarita and Nikolova, Dimitrinka and Pavlović, Stefan",
year = "2016",
abstract = "Diatomite supported Ni-Mg catalyst precursors (Ni-Mg/D) with a constant Ni/Mg ratio, prepared by the precipitation-deposition method using different nickel salts, sulfamate, nitrate, chloride, acetate or formate, were studied by hydrogen chemisorptions and temperature programmed reduction (H2- TPR).The results showed that the dispersion of nickel and the reducibility of the prepared catalyst precursors were different depending upon the counter ion of the nickel salt. Among the studied nickel salts, the best results for the dispersion of metallic Ni and reducibility of Ni-Mg/D catalyst precursors were achieved using nickel sulfamate salt.",
publisher = "Belgrade :  Society of Physical Chemists of Serbia",
journal = "Physical Chemistry 2016 (Proceedings) - 13th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade",
title = "Effect of Nickel Salts on the Dispersion of Nickel and Reducibility of Supported Ni-Mg Catalyst Precursors Prepared by Precipitation-Deposition",
volume = "1",
pages = "223-226",
url = "https://hdl.handle.net/21.15107/rcub_cer_3817"
}

Stanković, M., Krstić, J., Radonjić, V., Lončarević, D., Gabrovska, M., Nikolova, D.,& Pavlović, S.. (2016). Effect of Nickel Salts on the Dispersion of Nickel and Reducibility of Supported Ni-Mg Catalyst Precursors Prepared by Precipitation-Deposition. in Physical Chemistry 2016 (Proceedings) - 13th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade
Belgrade :  Society of Physical Chemists of Serbia., 1, 223-226.
https://hdl.handle.net/21.15107/rcub_cer_3817

Stanković M, Krstić J, Radonjić V, Lončarević D, Gabrovska M, Nikolova D, Pavlović S. Effect of Nickel Salts on the Dispersion of Nickel and Reducibility of Supported Ni-Mg Catalyst Precursors Prepared by Precipitation-Deposition. in Physical Chemistry 2016 (Proceedings) - 13th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade. 2016;1:223-226.
https://hdl.handle.net/21.15107/rcub_cer_3817 .

Stanković, Miroslav, Krstić, Jugoslav, Radonjić, Vojkan, Lončarević, Davor, Gabrovska, Margarita, Nikolova, Dimitrinka, Pavlović, Stefan, "Effect of Nickel Salts on the Dispersion of Nickel and Reducibility of Supported Ni-Mg Catalyst Precursors Prepared by Precipitation-Deposition" in Physical Chemistry 2016 (Proceedings) - 13th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade, 1 (2016):223-226,
https://hdl.handle.net/21.15107/rcub_cer_3817 .

TY  - JOUR
AU  - Krstić, Jugoslav
AU  - Gabrovska, Margarita
AU  - Lončarević, Davor
AU  - Nikolova, Dimitrinka
AU  - Radonjić, Vojkan
AU  - Vukelić, Nikola
AU  - Jovanović, Dušan M.
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1708
AB  - Sunflower oil hydrogenation process was studied on silica supported nickel catalysts. Three texturally different silica gel materials were used as supports for synthesis of Ni/SiO2 catalyst precursors. After precursors' reduction and paraffin oil impregnation, obtained catalysts were used in sunflower oil hydrogenation reaction. For catalytic test, a new type of catalyst feeder was constructed and presented. The hydrogenation activity of catalysts was monitored through the decrease of refractive index and hydrogen consumption. A correlation between iodine value, refractive index and hydrogen consumption was established. The reaction rate constants were obtained from fatty acid composition of partially hydrogenated oil and further studied for the investigation of possible reaction pathways. Kinetics and mechanisms were evaluated and tested with the aim to reduce the number of reactions participating in the reaction scheme. A set of ordinary differential equations, corresponding to the investigated model, was solved numerically by Gear's algorithm. It was shown that a number of significant reactions in a model depend on the activity of catalysts. More active catalyst results in more reaction pathways and more side chemical reactions.
PB  - Inst Chemical Engineers, Rugby
T2  - Chemical Engineering Research & Design
T1  - Influence of Ni/SiO2 activity on the reaction pathway in sunflower oil hydrogenation
VL  - 100
SP  - 72
EP  - 80
DO  - 10.1016/j.cherd.2015.05.001
ER  - 

@article{
author = "Krstić, Jugoslav and Gabrovska, Margarita and Lončarević, Davor and Nikolova, Dimitrinka and Radonjić, Vojkan and Vukelić, Nikola and Jovanović, Dušan M.",
year = "2015",
abstract = "Sunflower oil hydrogenation process was studied on silica supported nickel catalysts. Three texturally different silica gel materials were used as supports for synthesis of Ni/SiO2 catalyst precursors. After precursors' reduction and paraffin oil impregnation, obtained catalysts were used in sunflower oil hydrogenation reaction. For catalytic test, a new type of catalyst feeder was constructed and presented. The hydrogenation activity of catalysts was monitored through the decrease of refractive index and hydrogen consumption. A correlation between iodine value, refractive index and hydrogen consumption was established. The reaction rate constants were obtained from fatty acid composition of partially hydrogenated oil and further studied for the investigation of possible reaction pathways. Kinetics and mechanisms were evaluated and tested with the aim to reduce the number of reactions participating in the reaction scheme. A set of ordinary differential equations, corresponding to the investigated model, was solved numerically by Gear's algorithm. It was shown that a number of significant reactions in a model depend on the activity of catalysts. More active catalyst results in more reaction pathways and more side chemical reactions.",
publisher = "Inst Chemical Engineers, Rugby",
journal = "Chemical Engineering Research & Design",
title = "Influence of Ni/SiO2 activity on the reaction pathway in sunflower oil hydrogenation",
volume = "100",
pages = "72-80",
doi = "10.1016/j.cherd.2015.05.001"
}

Krstić, J., Gabrovska, M., Lončarević, D., Nikolova, D., Radonjić, V., Vukelić, N.,& Jovanović, D. M.. (2015). Influence of Ni/SiO2 activity on the reaction pathway in sunflower oil hydrogenation. in Chemical Engineering Research & Design
Inst Chemical Engineers, Rugby., 100, 72-80.
https://doi.org/10.1016/j.cherd.2015.05.001

Krstić J, Gabrovska M, Lončarević D, Nikolova D, Radonjić V, Vukelić N, Jovanović DM. Influence of Ni/SiO2 activity on the reaction pathway in sunflower oil hydrogenation. in Chemical Engineering Research & Design. 2015;100:72-80.
doi:10.1016/j.cherd.2015.05.001 .

Krstić, Jugoslav, Gabrovska, Margarita, Lončarević, Davor, Nikolova, Dimitrinka, Radonjić, Vojkan, Vukelić, Nikola, Jovanović, Dušan M., "Influence of Ni/SiO2 activity on the reaction pathway in sunflower oil hydrogenation" in Chemical Engineering Research & Design, 100 (2015):72-80,
https://doi.org/10.1016/j.cherd.2015.05.001 . .

TY  - JOUR
AU  - Radonjić, Vojkan
AU  - Krstić, Jugoslav
AU  - Lončarević, Davor
AU  - Jovanović, Dušan M.
AU  - Vukelić, Nikola
AU  - Stanković, Miroslav
AU  - Nikolova, Dimitrinka
AU  - Gabrovska, Margarita
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1825
AB  - Investigation was conducted in order to elucidate the possibility of using perlite as support for preparation of nickel based precursor catalyst, potentially applicable in vegetable oil hydrogenation process. On three differently prepared expanded perlite, nickel catalyst precursors with identical Ni/SiO2 = 1.1 and Ni/Mg = 10/1 ratios were synthesized by precipitation-deposition method. Different techniques, SEM micrography, He-pycnometry, calcimetry, Hg-porosimetry, N-2-physisorption, H-2-chemisorption and temperature programmed reduction, were used for characterization of obtained samples. Determining the precursor texture, morphology and reducibility shows a successfully deposited nickel phase on perlite support with promising properties for vegetable oil hydrogenation. Chosen precursor was reduced and passivated in paraffin oil and the obtained catalyst showed significant catalytic activity in the test of sunflower oil hydrogenation.
PB  - Maik Nauka/Interperiodica/Springer, New York
T2  - Russian Journal of Physical Chemistry A
T1  - Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation
VL  - 89
IS  - 13
SP  - 2359
EP  - 2366
DO  - 10.1134/S0036024415130294
ER  - 

@article{
author = "Radonjić, Vojkan and Krstić, Jugoslav and Lončarević, Davor and Jovanović, Dušan M. and Vukelić, Nikola and Stanković, Miroslav and Nikolova, Dimitrinka and Gabrovska, Margarita",
year = "2015",
abstract = "Investigation was conducted in order to elucidate the possibility of using perlite as support for preparation of nickel based precursor catalyst, potentially applicable in vegetable oil hydrogenation process. On three differently prepared expanded perlite, nickel catalyst precursors with identical Ni/SiO2 = 1.1 and Ni/Mg = 10/1 ratios were synthesized by precipitation-deposition method. Different techniques, SEM micrography, He-pycnometry, calcimetry, Hg-porosimetry, N-2-physisorption, H-2-chemisorption and temperature programmed reduction, were used for characterization of obtained samples. Determining the precursor texture, morphology and reducibility shows a successfully deposited nickel phase on perlite support with promising properties for vegetable oil hydrogenation. Chosen precursor was reduced and passivated in paraffin oil and the obtained catalyst showed significant catalytic activity in the test of sunflower oil hydrogenation.",
publisher = "Maik Nauka/Interperiodica/Springer, New York",
journal = "Russian Journal of Physical Chemistry A",
title = "Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation",
volume = "89",
number = "13",
pages = "2359-2366",
doi = "10.1134/S0036024415130294"
}

Radonjić, V., Krstić, J., Lončarević, D., Jovanović, D. M., Vukelić, N., Stanković, M., Nikolova, D.,& Gabrovska, M.. (2015). Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation. in Russian Journal of Physical Chemistry A
Maik Nauka/Interperiodica/Springer, New York., 89(13), 2359-2366.
https://doi.org/10.1134/S0036024415130294

Radonjić V, Krstić J, Lončarević D, Jovanović DM, Vukelić N, Stanković M, Nikolova D, Gabrovska M. Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation. in Russian Journal of Physical Chemistry A. 2015;89(13):2359-2366.
doi:10.1134/S0036024415130294 .

Radonjić, Vojkan, Krstić, Jugoslav, Lončarević, Davor, Jovanović, Dušan M., Vukelić, Nikola, Stanković, Miroslav, Nikolova, Dimitrinka, Gabrovska, Margarita, "Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation" in Russian Journal of Physical Chemistry A, 89, no. 13 (2015):2359-2366,
https://doi.org/10.1134/S0036024415130294 . .

TY  - JOUR
AU  - Stanković, Miroslav
AU  - Čupić, Željko
AU  - Gabrovska, Margarita
AU  - Banković, Predrag
AU  - Nikolova, Dimitrinka
AU  - Jovanović, Dušan M.
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1648
AB  - Diatomite supported NiMgAg catalysts, NiMgAg/D, were prepared by the precipitation-deposition method followed by drying, reduction and passivation. The preparation of the catalysts was performed with different loading of silver ranging from 0.16 to 5.88 wt% and constant molar ratios of SiO2/Ni and Mg/Ni equal to 1.07 and 0.1, respectively. The characterization of the catalysts was performed with N-2-physisorption, mercury intrusion porosimetry, H-2-chemisorption, X-ray diffraction, temperature programmed reduction, and scanning electron microscopy-energy dispersive X-ray analysis. The partial hydrogenation of soybean oil from initial to final iodine value of 90 was carried out at 160 A degrees C and H-2 pressure of 0.16 MPa using stirred semi-batch reactor. Soybean oil was hydrogenated over NiMgAg/D catalysts and NiMg/D catalyst (without silver addition) that was prepared using the same procedure as used for catalysts modified with silver. The selectivity towards trans fatty acid and saturated fatty acid formation was determined for both types of catalysts. By comparing the selectivity of the NiMgAg/D catalysts with the NiMg/D catalyst the promoting effect of silver modifier on the catalyst behavior in the hydrogenation of soybean oil was observed, and correlated with changing of the catalyst surface characteristics caused by the different Ag loading. It was found that the addition of silver to NiMg/D catalyst decreased both the selectivity towards trans fatty acids formation and the selectivity towards saturated fatty acids. For the same iodine value decay, the catalyst with the highest Ag loading (5.88 wt%) had the lowest level of both trans fatty acids and saturated fatty acids in the hydrogenation of soybean oil under studied operating conditions. The hydrogenation activity of NiMgAg/D catalysts is lower than NiMg/D catalyst and decreases with increasing Ag loading. The correlation between adsorption characteristics of the catalysts and their hydrogenation activities was established. The proposed simplified kinetic model to describe the kinetics of soybean oil hydrogenation gave a good description of the experimental data.
PB  - Springer Netherlands
T2  - Reaction Kinetics, Mechanisms and Catalysis
T1  - Characteristics and catalytic behavior of supported NiMgAg/D catalysts in the partial hydrogenation of soybean oil
VL  - 115
IS  - 1
SP  - 105
EP  - 127
DO  - 10.1007/s11144-014-0829-5
ER  - 

@article{
author = "Stanković, Miroslav and Čupić, Željko and Gabrovska, Margarita and Banković, Predrag and Nikolova, Dimitrinka and Jovanović, Dušan M.",
year = "2015",
abstract = "Diatomite supported NiMgAg catalysts, NiMgAg/D, were prepared by the precipitation-deposition method followed by drying, reduction and passivation. The preparation of the catalysts was performed with different loading of silver ranging from 0.16 to 5.88 wt% and constant molar ratios of SiO2/Ni and Mg/Ni equal to 1.07 and 0.1, respectively. The characterization of the catalysts was performed with N-2-physisorption, mercury intrusion porosimetry, H-2-chemisorption, X-ray diffraction, temperature programmed reduction, and scanning electron microscopy-energy dispersive X-ray analysis. The partial hydrogenation of soybean oil from initial to final iodine value of 90 was carried out at 160 A degrees C and H-2 pressure of 0.16 MPa using stirred semi-batch reactor. Soybean oil was hydrogenated over NiMgAg/D catalysts and NiMg/D catalyst (without silver addition) that was prepared using the same procedure as used for catalysts modified with silver. The selectivity towards trans fatty acid and saturated fatty acid formation was determined for both types of catalysts. By comparing the selectivity of the NiMgAg/D catalysts with the NiMg/D catalyst the promoting effect of silver modifier on the catalyst behavior in the hydrogenation of soybean oil was observed, and correlated with changing of the catalyst surface characteristics caused by the different Ag loading. It was found that the addition of silver to NiMg/D catalyst decreased both the selectivity towards trans fatty acids formation and the selectivity towards saturated fatty acids. For the same iodine value decay, the catalyst with the highest Ag loading (5.88 wt%) had the lowest level of both trans fatty acids and saturated fatty acids in the hydrogenation of soybean oil under studied operating conditions. The hydrogenation activity of NiMgAg/D catalysts is lower than NiMg/D catalyst and decreases with increasing Ag loading. The correlation between adsorption characteristics of the catalysts and their hydrogenation activities was established. The proposed simplified kinetic model to describe the kinetics of soybean oil hydrogenation gave a good description of the experimental data.",
publisher = "Springer Netherlands",
journal = "Reaction Kinetics, Mechanisms and Catalysis",
title = "Characteristics and catalytic behavior of supported NiMgAg/D catalysts in the partial hydrogenation of soybean oil",
volume = "115",
number = "1",
pages = "105-127",
doi = "10.1007/s11144-014-0829-5"
}

Stanković, M., Čupić, Ž., Gabrovska, M., Banković, P., Nikolova, D.,& Jovanović, D. M.. (2015). Characteristics and catalytic behavior of supported NiMgAg/D catalysts in the partial hydrogenation of soybean oil. in Reaction Kinetics, Mechanisms and Catalysis
Springer Netherlands., 115(1), 105-127.
https://doi.org/10.1007/s11144-014-0829-5

Stanković M, Čupić Ž, Gabrovska M, Banković P, Nikolova D, Jovanović DM. Characteristics and catalytic behavior of supported NiMgAg/D catalysts in the partial hydrogenation of soybean oil. in Reaction Kinetics, Mechanisms and Catalysis. 2015;115(1):105-127.
doi:10.1007/s11144-014-0829-5 .

Stanković, Miroslav, Čupić, Željko, Gabrovska, Margarita, Banković, Predrag, Nikolova, Dimitrinka, Jovanović, Dušan M., "Characteristics and catalytic behavior of supported NiMgAg/D catalysts in the partial hydrogenation of soybean oil" in Reaction Kinetics, Mechanisms and Catalysis, 115, no. 1 (2015):105-127,
https://doi.org/10.1007/s11144-014-0829-5 . .

TY  - CONF
AU  - Stanković, Miroslav
AU  - Marinković, Dalibor
AU  - Gabrovska, Margarita
AU  - Jovanović, Dušan M.
PY  - 2013
UR  - https://www.shd.org.rs/Icosecs8/
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2915
AB  - Nickel catalysts supported on diatomite (Ni/D) were prepared by deposition-precipitation
urea (DPU) method. The precipitation of Ni(II) phase onto diatomite surface was
performed under various deposition-precipitation times. The catalyst precursors prepared
with different nickel loading were then subjected through preparation steps including
drying, reduction and passivation under the same conditions.
Characterization of textural, structural and reducible properties was carried out using
following techniques: N2-physisorption, Hg-porosimetry, XRD, IR, TG-DTG and TPR.
The activity of DPU-Ni/D catalysts was tested in the reaction of hydrogenation of soybean
oil. This reaction was performed in a three-phase slurry reactor, under conditions
described in our previous paper.
Figures 1 and 2 show the activities of the 1-U-Ni/D, 2-U-Ni/D and 3-U-Ni/D in catalytic test
reaction of soybean oil hydrogenation. For hydrogenation reaction the highest activity was
observed for the catalyst sample 1-U-Ni/D with the lowest nickel loading. The activity of
catalyst samples increased in the following order: 1-U-Ni/D > 2-U-Ni/D > 3-U-Ni/D.
An observed trend of increasing activity with decrease of Ni loading is in good correlation
with the results obtained by the characterization of the catalyst surface and, in particular,
with reducible characteristics of prepared DPU-Ni/D catalyst samples.
PB  - Serbian Chemical Society
C3  - Eight International Conference of the Chemical Societies of the South-East European Countries ICOSEC
T1  - Activity of DPU-Ni/D hydrogenation catalysts prepared by urea method
VL  - 1
SP  - 71
UR  - https://hdl.handle.net/21.15107/rcub_cer_2915
ER  - 

@conference{
author = "Stanković, Miroslav and Marinković, Dalibor and Gabrovska, Margarita and Jovanović, Dušan M.",
year = "2013",
abstract = "Nickel catalysts supported on diatomite (Ni/D) were prepared by deposition-precipitation
urea (DPU) method. The precipitation of Ni(II) phase onto diatomite surface was
performed under various deposition-precipitation times. The catalyst precursors prepared
with different nickel loading were then subjected through preparation steps including
drying, reduction and passivation under the same conditions.
Characterization of textural, structural and reducible properties was carried out using
following techniques: N2-physisorption, Hg-porosimetry, XRD, IR, TG-DTG and TPR.
The activity of DPU-Ni/D catalysts was tested in the reaction of hydrogenation of soybean
oil. This reaction was performed in a three-phase slurry reactor, under conditions
described in our previous paper.
Figures 1 and 2 show the activities of the 1-U-Ni/D, 2-U-Ni/D and 3-U-Ni/D in catalytic test
reaction of soybean oil hydrogenation. For hydrogenation reaction the highest activity was
observed for the catalyst sample 1-U-Ni/D with the lowest nickel loading. The activity of
catalyst samples increased in the following order: 1-U-Ni/D > 2-U-Ni/D > 3-U-Ni/D.
An observed trend of increasing activity with decrease of Ni loading is in good correlation
with the results obtained by the characterization of the catalyst surface and, in particular,
with reducible characteristics of prepared DPU-Ni/D catalyst samples.",
publisher = "Serbian Chemical Society",
journal = "Eight International Conference of the Chemical Societies of the South-East European Countries ICOSEC",
title = "Activity of DPU-Ni/D hydrogenation catalysts prepared by urea method",
volume = "1",
pages = "71",
url = "https://hdl.handle.net/21.15107/rcub_cer_2915"
}

Stanković, M., Marinković, D., Gabrovska, M.,& Jovanović, D. M.. (2013). Activity of DPU-Ni/D hydrogenation catalysts prepared by urea method. in Eight International Conference of the Chemical Societies of the South-East European Countries ICOSEC
Serbian Chemical Society., 1, 71.
https://hdl.handle.net/21.15107/rcub_cer_2915

Stanković M, Marinković D, Gabrovska M, Jovanović DM. Activity of DPU-Ni/D hydrogenation catalysts prepared by urea method. in Eight International Conference of the Chemical Societies of the South-East European Countries ICOSEC. 2013;1:71.
https://hdl.handle.net/21.15107/rcub_cer_2915 .

Stanković, Miroslav, Marinković, Dalibor, Gabrovska, Margarita, Jovanović, Dušan M., "Activity of DPU-Ni/D hydrogenation catalysts prepared by urea method" in Eight International Conference of the Chemical Societies of the South-East European Countries ICOSEC, 1 (2013):71,
https://hdl.handle.net/21.15107/rcub_cer_2915 .

TY  - JOUR
AU  - Gabrovska, Margarita
AU  - Krstić, Jugoslav
AU  - Tzvetkov, P.
AU  - Tenchev, K.
AU  - Shopska, M.
AU  - Vukelić, Nikola
AU  - Jovanović, Dušan M.
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/829
AB  - Ni/SiO(2) materials with identical composition (SiO(2)/Ni = 1.0) have been synthesized by precipitation of Ni(NO(3))(2) center dot 6H(2)O solution with Na(2)CO(3) solution on the silica gel, obtained at three different pH values. The present investigation was undertaken in an endeavor to study the effects of the silica gel support type and the reduction temperature on the formation and dispersion of the metallic nickel phase in the reduced Ni/SiO(2) precursors of the vegetable oil hydrogenation catalyst. The physicochemical characterization of the unreduced and reduced precursors has been accomplished appropriately by powder X-ray diffraction, infrared spectroscopy, temperature programmed reduction and H(2)-chemisorption techniques. It can be stated that the texture peculiarities of the silica gels used as supports influence on the crystalline state and distribution of the deposited Ni-containing phases during the preparation of the precursors, on the reduction temperature of the investigated solids as well as on the bulk size and surface dispersion of the arising metallic nickel particles. It was shown that two types of Ni(2+)-species are formed during the synthesis procedure, namely basic nickel carbonate-like and Ni-phyllosilicate with different extent of presence, location and strength of interaction. The different location of these species is supposed to result in various strength of Ni-O and Ni-O-Si interaction, thus determining the overall reducibility of the precursors. It was specified that the Ni(2+)-species are strongly bonded to the surface of the silica gel obtained at neutral pH value and weakly bonded to the surface of those prepared in acidic and alkaline conditions. It was established that the precursor, derivates from the silica gel obtained at alkaline conditions, demonstrates both significant reduction of the Ni2+ ions at 430A degrees C and finely dispersed metallic nickel particles on its surface. High dispersion of the metallic nickel might be the crucial reason for achieving of high activity in the vegetable oil hydrogenation.
PB  - Maik Nauka/Interperiodica/Springer, New York
T2  - Russian Journal of Physical Chemistry A
T1  - Effect of the support and the reduction temperature on the formation of metallic nickel phase in Ni/silica gel precursors of vegetable oil hydrogenation catalysts
VL  - 85
IS  - 13
SP  - 2392
EP  - 2398
DO  - 10.1134/S0036024411130073
ER  - 

@article{
author = "Gabrovska, Margarita and Krstić, Jugoslav and Tzvetkov, P. and Tenchev, K. and Shopska, M. and Vukelić, Nikola and Jovanović, Dušan M.",
year = "2011",
abstract = "Ni/SiO(2) materials with identical composition (SiO(2)/Ni = 1.0) have been synthesized by precipitation of Ni(NO(3))(2) center dot 6H(2)O solution with Na(2)CO(3) solution on the silica gel, obtained at three different pH values. The present investigation was undertaken in an endeavor to study the effects of the silica gel support type and the reduction temperature on the formation and dispersion of the metallic nickel phase in the reduced Ni/SiO(2) precursors of the vegetable oil hydrogenation catalyst. The physicochemical characterization of the unreduced and reduced precursors has been accomplished appropriately by powder X-ray diffraction, infrared spectroscopy, temperature programmed reduction and H(2)-chemisorption techniques. It can be stated that the texture peculiarities of the silica gels used as supports influence on the crystalline state and distribution of the deposited Ni-containing phases during the preparation of the precursors, on the reduction temperature of the investigated solids as well as on the bulk size and surface dispersion of the arising metallic nickel particles. It was shown that two types of Ni(2+)-species are formed during the synthesis procedure, namely basic nickel carbonate-like and Ni-phyllosilicate with different extent of presence, location and strength of interaction. The different location of these species is supposed to result in various strength of Ni-O and Ni-O-Si interaction, thus determining the overall reducibility of the precursors. It was specified that the Ni(2+)-species are strongly bonded to the surface of the silica gel obtained at neutral pH value and weakly bonded to the surface of those prepared in acidic and alkaline conditions. It was established that the precursor, derivates from the silica gel obtained at alkaline conditions, demonstrates both significant reduction of the Ni2+ ions at 430A degrees C and finely dispersed metallic nickel particles on its surface. High dispersion of the metallic nickel might be the crucial reason for achieving of high activity in the vegetable oil hydrogenation.",
publisher = "Maik Nauka/Interperiodica/Springer, New York",
journal = "Russian Journal of Physical Chemistry A",
title = "Effect of the support and the reduction temperature on the formation of metallic nickel phase in Ni/silica gel precursors of vegetable oil hydrogenation catalysts",
volume = "85",
number = "13",
pages = "2392-2398",
doi = "10.1134/S0036024411130073"
}

Gabrovska, M., Krstić, J., Tzvetkov, P., Tenchev, K., Shopska, M., Vukelić, N.,& Jovanović, D. M.. (2011). Effect of the support and the reduction temperature on the formation of metallic nickel phase in Ni/silica gel precursors of vegetable oil hydrogenation catalysts. in Russian Journal of Physical Chemistry A
Maik Nauka/Interperiodica/Springer, New York., 85(13), 2392-2398.
https://doi.org/10.1134/S0036024411130073

Gabrovska M, Krstić J, Tzvetkov P, Tenchev K, Shopska M, Vukelić N, Jovanović DM. Effect of the support and the reduction temperature on the formation of metallic nickel phase in Ni/silica gel precursors of vegetable oil hydrogenation catalysts. in Russian Journal of Physical Chemistry A. 2011;85(13):2392-2398.
doi:10.1134/S0036024411130073 .

Gabrovska, Margarita, Krstić, Jugoslav, Tzvetkov, P., Tenchev, K., Shopska, M., Vukelić, Nikola, Jovanović, Dušan M., "Effect of the support and the reduction temperature on the formation of metallic nickel phase in Ni/silica gel precursors of vegetable oil hydrogenation catalysts" in Russian Journal of Physical Chemistry A, 85, no. 13 (2011):2392-2398,
https://doi.org/10.1134/S0036024411130073 . .

TY  - JOUR
AU  - Stanković, Miroslav
AU  - Gabrovska, Margarita
AU  - Krstić, Jugoslav
AU  - Tzvetkov, P.
AU  - Shopska, M.
AU  - Tsacheva, T.
AU  - Banković, Predrag
AU  - Edreva-Kardjieva, R.
AU  - Jovanović, D.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/593
AB  - Silver modified Mg-Ni/diatomite materials with ratios of SiO2/Ni = 1.07 and Mg/Ni = 0.1, differing in Ag content (Ag/Ni = 0.025 and 0.1) were prepared by the precipitation-deposition method. The effects of silver presence and content on the structure, morphology, texture and H2-adsorption capacity of the obtained precursors were studied by X-ray diffraction, scanning electron microscopy, Hg-porosimetry and H2-chemisorption techniques. The catalytic performance of the corresponding catalysts in the soybean oil hydrogenation was investigated. The increase of the silver loading resulted in the development of macroporosity and increase in the total sample porosity. The decrease of both H2-adsorption capacity and hydrogenation activity are related to the metallic silver covering and blocking effects on the Ni2+ species, thus hampering the access of hydrogen. The decrease of hydrogenation activity and favorable limiting of cis-trans isomerization on the silver modified catalyst are explained by Horiuti-Polanyi mechanism based on the assumption that hydrogenation and isomerization proceed at the same active metallic nickel sites via half-hydrogenated intermediates. It was shown that the adjustment of the catalyst composition by changing the content of silver modifier offers the possibility to control the total amount of solid fat content, stearic acid and detrimental trans fatty acids in the hydrogenated derivatives. The catalyst with higher silver content is proposed as a promising candidate for selective edible oil hydrogenation catalyst.
PB  - Elsevier
T2  - Journal of Molecular Catalysis A: Chemical
T1  - Effect of silver modification on structure and catalytic performance of Ni-Mg/diatomite catalysts for edible oil hydrogenation
VL  - 297
IS  - 1-2
SP  - 54
EP  - 62
DO  - 10.1016/j.molcata.2008.09.004
ER  - 

@article{
author = "Stanković, Miroslav and Gabrovska, Margarita and Krstić, Jugoslav and Tzvetkov, P. and Shopska, M. and Tsacheva, T. and Banković, Predrag and Edreva-Kardjieva, R. and Jovanović, D.",
year = "2009",
abstract = "Silver modified Mg-Ni/diatomite materials with ratios of SiO2/Ni = 1.07 and Mg/Ni = 0.1, differing in Ag content (Ag/Ni = 0.025 and 0.1) were prepared by the precipitation-deposition method. The effects of silver presence and content on the structure, morphology, texture and H2-adsorption capacity of the obtained precursors were studied by X-ray diffraction, scanning electron microscopy, Hg-porosimetry and H2-chemisorption techniques. The catalytic performance of the corresponding catalysts in the soybean oil hydrogenation was investigated. The increase of the silver loading resulted in the development of macroporosity and increase in the total sample porosity. The decrease of both H2-adsorption capacity and hydrogenation activity are related to the metallic silver covering and blocking effects on the Ni2+ species, thus hampering the access of hydrogen. The decrease of hydrogenation activity and favorable limiting of cis-trans isomerization on the silver modified catalyst are explained by Horiuti-Polanyi mechanism based on the assumption that hydrogenation and isomerization proceed at the same active metallic nickel sites via half-hydrogenated intermediates. It was shown that the adjustment of the catalyst composition by changing the content of silver modifier offers the possibility to control the total amount of solid fat content, stearic acid and detrimental trans fatty acids in the hydrogenated derivatives. The catalyst with higher silver content is proposed as a promising candidate for selective edible oil hydrogenation catalyst.",
publisher = "Elsevier",
journal = "Journal of Molecular Catalysis A: Chemical",
title = "Effect of silver modification on structure and catalytic performance of Ni-Mg/diatomite catalysts for edible oil hydrogenation",
volume = "297",
number = "1-2",
pages = "54-62",
doi = "10.1016/j.molcata.2008.09.004"
}

Stanković, M., Gabrovska, M., Krstić, J., Tzvetkov, P., Shopska, M., Tsacheva, T., Banković, P., Edreva-Kardjieva, R.,& Jovanović, D.. (2009). Effect of silver modification on structure and catalytic performance of Ni-Mg/diatomite catalysts for edible oil hydrogenation. in Journal of Molecular Catalysis A: Chemical
Elsevier., 297(1-2), 54-62.
https://doi.org/10.1016/j.molcata.2008.09.004

Stanković M, Gabrovska M, Krstić J, Tzvetkov P, Shopska M, Tsacheva T, Banković P, Edreva-Kardjieva R, Jovanović D. Effect of silver modification on structure and catalytic performance of Ni-Mg/diatomite catalysts for edible oil hydrogenation. in Journal of Molecular Catalysis A: Chemical. 2009;297(1-2):54-62.
doi:10.1016/j.molcata.2008.09.004 .

Stanković, Miroslav, Gabrovska, Margarita, Krstić, Jugoslav, Tzvetkov, P., Shopska, M., Tsacheva, T., Banković, Predrag, Edreva-Kardjieva, R., Jovanović, D., "Effect of silver modification on structure and catalytic performance of Ni-Mg/diatomite catalysts for edible oil hydrogenation" in Journal of Molecular Catalysis A: Chemical, 297, no. 1-2 (2009):54-62,
https://doi.org/10.1016/j.molcata.2008.09.004 . .

TY  - CONF
AU  - Gabrovska, Margarita
AU  - Nikolova, Dimitrinka
AU  - Krstić, Jugoslav
AU  - Stanković, Miroslav
AU  - Stefanov, P.
AU  - Edreva-Kardjieva, R.
AU  - Jovanović, D.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/583
AB  - Two series of silver modified Ni-Mg materials were synthesized by precipitation-deposition on SiO2 support derived from two silica sources: diatomite activated at 800°C (Series a; Mg/Ni = 0.1 and SiO 2/Ni = 1.07) and synthetic water glass (Series b; Mg/Ni = 0.1 and SiO2/Ni = 1.15). The modification with silver was made at three molar Ag/Ni ratios, namely 0.0025, 0.025, and 0.1. The effects of the source of the silica support and the silver presence and content on the nickel state in the silver modified reduced-passivated NiMg/SiO2 precursors of the vegetable oil hydrogenation catalyst were established by X-ray diffraction and X-ray photoelectron spectroscopy techniques. The passivation procedure was applied in order to protect the metallic nickel particles from further oxidation. The crystallization of the formed nickel hydrosilicate phases depends on the source of the silica support, more expressed in the diatomite supported samples. It was shown that the silver modification of the NiMg/SiO2 precursors enhances the reduction of the nickel hydrosilicates accompanied by formation of relatively smaller metallic nickel particles, more pronounced in the water glass supported precursors. The increase of the silver content in the water glass deposited samples is responsible for the metallic nickel dispersion increase. The higher content of the Ni0 particles on the surface of the diatomite deposited samples is in accordance with the higher stability of the larger metallic nickel crystallites to oxidation during the passivation step. On contrary, higher dispersed Ni0 particles on the surface of the water glass supported samples are more susceptible to the oxida
PB  - Maik Nauka/Interperiodica/Springer, New York
C3  - Russian Journal of Physical Chemistry A
T1  - The state of nickel in the silver modified NiMg/SiO2 vegetable oil hydrogenation catalysts
VL  - 83
IS  - 9
SP  - 1461
EP  - 1467
DO  - 10.1134/S0036024409090088
ER  - 

@conference{
author = "Gabrovska, Margarita and Nikolova, Dimitrinka and Krstić, Jugoslav and Stanković, Miroslav and Stefanov, P. and Edreva-Kardjieva, R. and Jovanović, D.",
year = "2009",
abstract = "Two series of silver modified Ni-Mg materials were synthesized by precipitation-deposition on SiO2 support derived from two silica sources: diatomite activated at 800°C (Series a; Mg/Ni = 0.1 and SiO 2/Ni = 1.07) and synthetic water glass (Series b; Mg/Ni = 0.1 and SiO2/Ni = 1.15). The modification with silver was made at three molar Ag/Ni ratios, namely 0.0025, 0.025, and 0.1. The effects of the source of the silica support and the silver presence and content on the nickel state in the silver modified reduced-passivated NiMg/SiO2 precursors of the vegetable oil hydrogenation catalyst were established by X-ray diffraction and X-ray photoelectron spectroscopy techniques. The passivation procedure was applied in order to protect the metallic nickel particles from further oxidation. The crystallization of the formed nickel hydrosilicate phases depends on the source of the silica support, more expressed in the diatomite supported samples. It was shown that the silver modification of the NiMg/SiO2 precursors enhances the reduction of the nickel hydrosilicates accompanied by formation of relatively smaller metallic nickel particles, more pronounced in the water glass supported precursors. The increase of the silver content in the water glass deposited samples is responsible for the metallic nickel dispersion increase. The higher content of the Ni0 particles on the surface of the diatomite deposited samples is in accordance with the higher stability of the larger metallic nickel crystallites to oxidation during the passivation step. On contrary, higher dispersed Ni0 particles on the surface of the water glass supported samples are more susceptible to the oxida",
publisher = "Maik Nauka/Interperiodica/Springer, New York",
journal = "Russian Journal of Physical Chemistry A",
title = "The state of nickel in the silver modified NiMg/SiO2 vegetable oil hydrogenation catalysts",
volume = "83",
number = "9",
pages = "1461-1467",
doi = "10.1134/S0036024409090088"
}

Gabrovska, M., Nikolova, D., Krstić, J., Stanković, M., Stefanov, P., Edreva-Kardjieva, R.,& Jovanović, D.. (2009). The state of nickel in the silver modified NiMg/SiO2 vegetable oil hydrogenation catalysts. in Russian Journal of Physical Chemistry A
Maik Nauka/Interperiodica/Springer, New York., 83(9), 1461-1467.
https://doi.org/10.1134/S0036024409090088

Gabrovska M, Nikolova D, Krstić J, Stanković M, Stefanov P, Edreva-Kardjieva R, Jovanović D. The state of nickel in the silver modified NiMg/SiO2 vegetable oil hydrogenation catalysts. in Russian Journal of Physical Chemistry A. 2009;83(9):1461-1467.
doi:10.1134/S0036024409090088 .

Gabrovska, Margarita, Nikolova, Dimitrinka, Krstić, Jugoslav, Stanković, Miroslav, Stefanov, P., Edreva-Kardjieva, R., Jovanović, D., "The state of nickel in the silver modified NiMg/SiO2 vegetable oil hydrogenation catalysts" in Russian Journal of Physical Chemistry A, 83, no. 9 (2009):1461-1467,
https://doi.org/10.1134/S0036024409090088 . .

TY  - CONF
AU  - Nikolova, Dimitrinka
AU  - Stanković, Miroslav
AU  - Simić, Sanja

AU  - Gabrovska, Margarita
AU  - Stefanov, Plamen
AU  - Edreva-Kardjieva, Rumeana
PY  - 2008
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6323
AB  - Two series of (Ag)NiMg/SiO2 catalysts are synthesized on SiO2 support derived
from two silica sources: diatomite activated at 800oC (Series a; Mg/Ni=0.1 and
SiO2/Ni=1.07) and synthetic water glass (Series b; Mg/Ni=0.1 and SiO2/Ni=1.15).
The modification with silver is made at three molar Ag/Ni ratios, namely 0.0025,
0.025 and 0.1.
The effect of the source of SiO2 support as well as of the Ag presence and
content on the nickel oxidation state in the co-precipitated (Ag)NiMg/SiO2
catalysts after reduction-passivation procedure are studied by XPS.
The peak-fitting of the composite Ni2p level confirms that nickel on the
surface is presented in Ni0 and Ni2+ oxidation states. The higher content of Ni0 on
the surface of the diatomite supported catalysts shows that the metallic nickel is
more stable to oxidation in comparison of the water glass supported ones.
PB  - Society of Physical Chemists of Serbia
C3  - Proceedings - 9th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Physical Chemistry 2008, September 24-26, 2008,  Belgrade, Serbia
T1  - XPS study of the nickel oxidation state in the reduced (Ag)NiMg/SiO2 vegetable oil hydrogenation catalysts
VL  - I
SP  - 175
EP  - 177
UR  - https://hdl.handle.net/21.15107/rcub_cer_6323
ER  - 

@conference{
author = "Nikolova, Dimitrinka and Stanković, Miroslav and Simić, Sanja
 and Gabrovska, Margarita and Stefanov, Plamen and Edreva-Kardjieva, Rumeana",
year = "2008",
abstract = "Two series of (Ag)NiMg/SiO2 catalysts are synthesized on SiO2 support derived
from two silica sources: diatomite activated at 800oC (Series a; Mg/Ni=0.1 and
SiO2/Ni=1.07) and synthetic water glass (Series b; Mg/Ni=0.1 and SiO2/Ni=1.15).
The modification with silver is made at three molar Ag/Ni ratios, namely 0.0025,
0.025 and 0.1.
The effect of the source of SiO2 support as well as of the Ag presence and
content on the nickel oxidation state in the co-precipitated (Ag)NiMg/SiO2
catalysts after reduction-passivation procedure are studied by XPS.
The peak-fitting of the composite Ni2p level confirms that nickel on the
surface is presented in Ni0 and Ni2+ oxidation states. The higher content of Ni0 on
the surface of the diatomite supported catalysts shows that the metallic nickel is
more stable to oxidation in comparison of the water glass supported ones.",
publisher = "Society of Physical Chemists of Serbia",
journal = "Proceedings - 9th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Physical Chemistry 2008, September 24-26, 2008,  Belgrade, Serbia",
title = "XPS study of the nickel oxidation state in the reduced (Ag)NiMg/SiO2 vegetable oil hydrogenation catalysts",
volume = "I",
pages = "175-177",
url = "https://hdl.handle.net/21.15107/rcub_cer_6323"
}

Nikolova, D., Stanković, M., Simić, S., Gabrovska, M., Stefanov, P.,& Edreva-Kardjieva, R.. (2008). XPS study of the nickel oxidation state in the reduced (Ag)NiMg/SiO2 vegetable oil hydrogenation catalysts. in Proceedings - 9th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Physical Chemistry 2008, September 24-26, 2008,  Belgrade, Serbia
Society of Physical Chemists of Serbia., I, 175-177.
https://hdl.handle.net/21.15107/rcub_cer_6323

Nikolova D, Stanković M, Simić S, Gabrovska M, Stefanov P, Edreva-Kardjieva R. XPS study of the nickel oxidation state in the reduced (Ag)NiMg/SiO2 vegetable oil hydrogenation catalysts. in Proceedings - 9th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Physical Chemistry 2008, September 24-26, 2008,  Belgrade, Serbia. 2008;I:175-177.
https://hdl.handle.net/21.15107/rcub_cer_6323 .

Nikolova, Dimitrinka, Stanković, Miroslav, Simić, Sanja
, Gabrovska, Margarita, Stefanov, Plamen, Edreva-Kardjieva, Rumeana, "XPS study of the nickel oxidation state in the reduced (Ag)NiMg/SiO2 vegetable oil hydrogenation catalysts" in Proceedings - 9th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Physical Chemistry 2008, September 24-26, 2008,  Belgrade, Serbia, I (2008):175-177,
https://hdl.handle.net/21.15107/rcub_cer_6323 .