A Direct Formaldehyde Fuel Cell for CO2‐Emission Free Co‐generation of Electrical Energy and Valuable Chemical/Hydrogen

Converting carbon-based molecular fuels into electricity efficiently and cleanly without emitting CO2 remains a challenge. Conventional fuel cells using noble metals as anode catalysts often suffer performance degradation due to CO poisoning and a host of problems associated with CO2 production. This study provides a CO2 -emission-free direct formaldehyde fuel cell. It enables a flow of electricity while producing H2 and valuable formate. Unlike conventional carbon-based molecules electrooxidation, formaldehyde 1-electron oxidation is performed on the Cu anode with high selectivity, thus generating formate and H2 without undergoing CO2 pathway. In addition, the fuel cell produces 0.62 Nm3 H2 and 53 mol formate per 1 kWh of electricity generated, with an open circuit voltage of up to 1 V and a peak power density of 350 mW cm-2 . This study puts forward a zero-carbon solution for the efficient utilization of carbon-based molecule fuels that generates electricity, hydrogen and valuable chemicals in synchronization.