Electrochemical CO2 reduction over Pb electrodes modified with group 10, 11, and 14 elements

Abstract

Surface modification method is a good strategy of improving electrocatalyst performance in CO2 reduction. Herein, lead (Pb) electrode was modified with groups 10 (Ni, Pd, and Pt), 11 (Cu, Ag, and Au), and 14 (Si, Ge, and Sn) elements, and their electrochemical CO2 reduction performances were tested under various conditions of applied potentials, electrolytes, and light irradiation conditions. Major products were observed to be formate and hydrogen and their Faradaic efficiencies were competitive reached to 71% and 28%, respectively. When H2 was increased formate was inversely decreased. Minor products of CO, acetone, and CH4 were mainly dependent on applied potentials and overlayer metals. Overlayer Pt, Pd, and Au metals were relatively stable on the Pb surface during amperometry while others were unstable on the surface. Pb surfaces were observed to be reconstructed during CO2 reduction into nanosheets, nanoplates, nanorods, and nanoislands depending on the applied potentials and overlayer metals. Overall, the present study provides very useful information on the development of Pb-based electrocatalysts for CO2 recycling by electrochemical CO2 reduction.