Oxidation of formic acid on platinum electrodeposited on polished and oxidized glassy carbon

Abstract

Formic acid oxidation at platinum electrochemically deposited on polished (GC/Pt) and oxidized glassy carbon (GC(ox)/Pt) was examined with the objective of studying the effect of electrochemical treatment of the support on deposition of platinum and on the activity of Pt catalyst. The electrodes were characterised by STM and XPS techniques. The oxidative treatment of the support leads to deposition of smaller Pt particles in comparison with the one on the polished substrate. The XPS spectra indicated the increased fraction of functional (acidic) groups on the treated support as well as the higher fraction of oxygen containing species on Pt catalyst deposited on oxidised referring to Pt deposited on polished substrate. The activity of GC(ox)/Pt electrode is increased by the factor of 2-4 for formic acid oxidation compared to the activity of GC/Pt electrode. This result is explained by the oxidative removal Of COad species leading to enhanced amount of Pt free sites available for direct formic acid oxidation to CO2.