Mikrotalasna sinteza platinskih legura za uspesnu oksidaciju metanola u gorivnim spregovima

Abstract

Ova studija je fokusirana na pronalaženje novih načina sinteze katalizatora na bazi platine koji pokazuju dobru efikasnost za reakciju oksidacije metanola. Nanočestice PtZn, PtSn i PtSnZn su sintetizovane korišćenjem poliol metode uz pomoć mikrotalasnog zagrevanja i deponovane na ugljeničnu podlogu Vulcan XC-72R. Elektrohemijsko ponašanje sintetizovanih katalizatora je ispitivano korišćenjem ciklične voltametrije i hronoamperometrijske tehnike. Fizičkohemijska svojstva dobijenih katalizatora su okarakterisana transmisionom elektronskom mikroskopijom (TEM), termogravimetrijskom analizom (TGA) i energetsko disperzivnom spektroskopijom (EDS). Prema TEM analizi svi katalizatori imaju male čestice prilično slične veličine između 1 i 3 nm. Dobijeni rezultati su potvrdili uspešnu sintezu katalizatora na bazi Pt. Dodavanje Zn i Sn u Pt katalizator značajno poboljšava aktivnost oksidacije metanola u poređenju sa Pt/C referentnim katalizatorom. Testovi stabilnosti takođe dokazuju slabije trovanje i ukazuju na bolju stabilnost i veću toleranciju na CO intermedijere. Uočena visoka katalitička aktivnost i dobra stabilnost u reakciji oksidacije metanola sintetizovanih katalizatora mogu se pripisati veoma efikasnoj mikrotalasnoj sintezi i dobro izbalansiranom sadržaju Zn i Sn kao legirajućih metala.

This study is focused on novel ways for creating Pt alloy catalysts that are more effective for the methanol oxidation reaction. PtZn, PtSn and PtSnZn nanoparticles were produced using the microwave assisted polyol method and were supported on high surface area carbon Vulcan XC-72R material. The electrochemical behaviour of synthesized catalysts was investigated utilizing the cyclic voltammetry and chronoamperometric technique. To determine the catalyst's physicochemical characteristics, transmission electron microscopy analysis (TEM), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA) were used. According to TEM analysis all catalysts have small particles of rather similar size between 1 and 3 nm. The obtained results confirmed the successful synthesis of Pt-based catalyst. Addition of Zn and Sn to Pt significantly improves methanol oxidation activity in comparison to Pt/C benchmark catalyst. Stability tests also prove the lower poisoning and indicate better stability and higher tolerance to CO-like intermediaries. The observed high catalytic activity and good stability in the methanol oxidation reaction of synthesized catalyst can be ascribed to the very efficient microwave synthesis and well-balanced content of Zn and Sn as alloying metal.