Analysis of the electrochemical quartz crystal microbalance response during oxidation of carbon oxides adsorption products on platinum group metals and alloys

Abstract

The analysis of the electrochemical quartz crystal microbalance (EQCM) signal is presented for the case of oxidation of carbon oxides adsorption products on Pt, Rh, and their alloys. It is demonstrated that the EQCM response can be roughly approximated by the mass balance involving adsorption/desorption of various species (carbon oxides, oxygen, anions, and water molecules) and metal dissolution. The results obtained by the EQCM are in good agreement with the electrochemical data and confirm the domination of CO radicals among the products of CO2 reduction and CO adsorption on Pt-rich electrodes. In the case of Rh-rich electrodes, the existence of additional species (CHO or COH), more reduced than CO, is suggested.