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

Abstract

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.