Electrocatalytic Activity of Pt Oxide Electrode for CO2 Reduction

Abstract

CO 2 electrochemical reduction. Cyclic voltammetry of the Pt oxide electrode in a CO 2 -saturated H 2 SO 4 solution showed a definite anodic peak at 0.6-0.8 V vs. SHE, which was not observed in an Ar-deaerated electrolyte. Thus, it was determined that the anodic peak could be related to the re-oxidation of the reduction product of CO 2 during cathodic polarization. The activity of the Pt oxide electrode for CO 2 reduction was much higher than that of the Pt electrode. It was concluded that the residual oxygen, which was hardly detected in the Pt electrode, improved the activity for CO 2 electrochemical reduction on the Pt oxide electrode. Gas chromatography-mass spectrometry of the electrolytic solution after CO 2 reduction revealed that the reduction product was mainly CH 3 OH. These results should be very useful for developing a new electrochemical reduction system for converting CO 2 into CH 3 OH.