Preparation of a Pb loaded gas diffusion electrode and its application to CO2 electroreduction

A Pb loaded gas diffusion electrode was fabricated and used for the electroreduction of CO2 to formic acid. The Pb/C catalyst was prepared by isometric impregnation. The crystal structure and morphology of the Pb/C catalyst were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The preparation conditions of the gas diffusion electrode were optimized by adjusting the amounts of polytetrafluoroethylene (PTFE) in the gas diffusion layer and acetylene black in the catalytic layer. The electrochemical performance of the as-prepared gas diffusion electrode was studied by chronoamperometry and cyclic voltammetry. The optimized gas diffusion electrode showed good catalytic performance for the electroreduction of CO2. The current efficiency of formic acid after 1 h of operation reached a maximum of 22% at −2.0 V versus saturated calomel electrode (SCE).