Pt-Regulated Dynamic Cu(0) Regeneration in CuPt Alloy Enables High-Efficiency Self-Driven Formaldehyde Fuel Cells for Potassium Formate Production.

Efficient and clean conversion of carbon-based molecular fuels into electricity without CO2 emission remains a great challenge. Herein, formaldehyde was employed as a novel fuel catalyzed by a Cu30PtX/CF anode, which was fabricated via electrodeposition. The electronic interaction between Pt and Cu boosts H* dimerization into H2 (the rate-determining step), facilitates the desorption of formic acid, and promotes the regeneration of Cu0 active sites, thus enhancing the catalytic activity and stability and broadening the potential window for formaldehyde oxidation. Furthermore, a direct formaldehyde fuel cell was constructed, in which the one-electron oxidation of formaldehyde proceeds with high selectivity on the Cu anode without the CO2 formation pathway. This fuel cell delivers an open-circuit voltage of 0.94 V and a peak power density of 34.3 mW cm-2, and enables the highly selective production of potassium formate while generating electricity spontaneously with a Faradaic efficiency approaching 100%. This work realizes the co-generation of electrical energy and high-value-added chemicals, providing a new strategy and mechanistic basis for the design of high-performance direct formaldehyde fuel cells (DFFC).