Influence of the nature of the carbon support on the activity of Pt/C catalysts for ethanol and carbon monoxide oxidation

The electrooxidation of ethanol and carbon monoxide on Pt nanoparticles (NPs) supported on carbon nanofibers (CNFs) and carbon blacks (oxidized and non-oxidized) is studied. Quite similar characteristics are found for Pt NPs, including particle size and crystal phases, regardless of the nature of carbon support. Cyclic voltammetries and current-transient curves show higher ethanol oxidation current density for Pt/CNF than for Pt/Vulcan. In situ spectroelectrochemical techniques including Fourier transform infrared spectroscopy (FTIR) and differential electrochemical mass spectrometry (DEMS), are employed in order to identify adsorbed reaction intermediates and products. Pt/CNF results in a lower CO poisoning of the NP surface compared to Pt/Vulcan, allowing higher amount of free Pt active sites for the oxidation of ethanol which leads to the formation of acetic acid during the reaction.