Efficient Electrochemical Conversion of CO2 to CO Using a Cathode with Porous Catalyst Layer under Mild pH Conditions

Electrochemical conversion of CO2 into fuels or chemical feedstocks is one of the most promising methods for solving the problems of both fossil fuel depletion and global warming. Herein, we report that a CO2 electrolysis cell equipped with a polymer electrolyte membrane and cathode loaded with gold nanoparticles as an electrocatalyst produces carbon monoxide with >90% faradaic efficiency at a current density of 700 mA/cm(2) under mild pH conditions. The catalyst layer formed on the electrode had a porous structure that facilitates CO2 diffusion, enabling operation at high current density.