(Invited) Kinetic Modeling of Ethanol Electro-Oxidation on Co-Ni-Mo-P Electrocatalyst

Abstract

A rotating disk electrode technique was used to study the kinetics of ethanol electro-oxidation on multi-alloy composition of CoNiMoP deposited on catalyzed carbon substrate (CCS). A simple kinetic model for ethanol oxidation on CoNiMoP/CCS was developed with the assumption of a simultaneous generation of two main products – CH3CHO (acetaldehyde) and CH3COOH (acetic acid) and the experimental result was used to evaluate the kinetic parameters of the model. In the developed model, if only one of the two products- CH3CHO or CH3COOH was generated, the result showed that at high ethanol concentration, the ethanol reaction mechanism followed the acetaldehyde route while at low ethanol concentration, the mechanism led to acetic acid and carbon dioxide route. However, a modified model in which a simultaneous production of both CH3CHO and CH3COOH occurred, showed that ethanol oxidized rapidly to CH3COOH. Additionally, the effect of the rotation speed (400 or 900 rpm) on the reaction was investigated and the result showed that the speed did not affect the mechanism because the experimental results were closer to the CH3COOH curves for both cases (400 and 900 rpm), but rotation speed affected the mole fraction of CH3COOH and CH3CHO.