Effects of Carbon Materials on Formation of CoN4Cx Active Site of Co-P4VPy/Carbon Catalysts for Selective CO2 Electroreduction to CO

Abstract Development of active electrocatalyst for CO 2 reduction to useful chemicals would be essential factor to achieve the carbon neutral society. The Co poly-4-vinyl-pyridine (P4VPy)/Ketjenblack (KB) activated thermally was found for an active electrocatalyst in the electroreduction of CO 2 with water by the solid-polymer-electrolyte, SPE, electrolysis cell. Various carbon supports were applied instead of KB. Contents of CoN 4 C x , CoO and Co 0 compounds on activated electrocatalysts were determined by linear combination fitting, LCF, of X-ray absorption near edge structure, XANES. Pyrolysis of the catalyst precursor for activation was essential and kinds of carbon supports strongly influenced formation of the Co compounds. It was revealed that the content of CoN 4 C x related to the current efficiency of the CO formation and that of CoO and Co 0 related the H 2 formation. Graphical Abstract Relation between Faraday efficiency to CO and content of CoN 4 C x