Electrochemically Fabricated Pd-In Catalysts for Carbon Dioxide-Formate/Formic Acid Inter-Conversion

Pd-In catalysts were electrochemically prepared for application in unitized regenerative fuel cells based on carbon dioxide and formic acid. The morphology and composition of the Pd-In catalysts were controlled by varying the concentration of the In precursor in a deposition bath. The catalytic activity was then investigated for both formic acid oxidation and carbon dioxide reduction reactions. In order to enhance their activity and stability, the Pd-In catalysts were annealed under Ar atmosphere, resulting in better activities than those of the as-deposited Pd-In catalysts. Although the activity was not excellent, this effort aimed at the development of bimetallic catalysts paves the way toward inter-conversion electrodes active in both the electrochemical carbon dioxide reduction and formic acid oxidation reactions.