Experimental Verification of Mixed-potential-driven Catalysis

Abstract

Mixed-potential-driven catalysis could be a novel strategy to control catalytic selectivity. In this mechanism, anodic and cathodic reactions occur simultaneously, forming a mixed potential on the nano-anode and nano-cathode composed of a supported catalyst. To prove the mixed-potential-driven catalysis, we developed a new model reactor with separated electrodes to directly measure currents between anodic and cathodic reactions under high-pressure conditions. We observed that reaction currents supported mixed-potential reactions only when a CO₂/H₂ mixture was introduced into the model reactor with Cu and Pd electrodes without separating CO₂ and H₂. This indicates that CO₂ reduction and H₂ oxidation occurred simultaneously on the Cu and Pd catalysts, respectively, based on the catalytic activity via the mixed-potential mechanism. The products of reaction for 18 h at 373 K were CO, methanol, and ethanol.