Electrochemical carbon dioxide (CO 2 ) reduction (eCO 2 R) is an emerging technology that is capable of producing various organic chemical compounds out of CO 2 . Being integrated with renewable energy systems, eCO 2 R has been known as a promising alternative to conventional fossil-based chemical production. Recent research on eCO 2 R has focused on synthesis of novel catalysts for the production of, e.g., carbon monoxide, formic acid, ethylene, and ethanol .