Electron-rich Pt active sites enable efficient complete dehydrogenation electrooxidation of formic acid on Pt/Ag@Bi₂Te₃ triple-phase heterointerfaces

Realizing the dehydrogenation direct pathway of formic acid electrooxidation reaction (FAOR) via sequential dehydrogenation steps is crucial for direct formic acid proton exchange membrane fuel cells (DFAPEMFCs). Herein, a two-dimensional porous Pt/Ag@Bi₂Te₃ electrocatalyst featuring a triple-phase heterointerface is prepared via a visible light-induced strategy. The heterointerface effect and metal–support effect endow the Pt active sites with local electron-rich properties, thereby facilitating attack on the H atom of H–COO–H to cleave the C–H and O–H bonds and realize the direct pathway. The Pt/Ag@Bi₂Te₃ demonstrates remarkable FAOR mass and specific activities of 10.7 A·mg_Pt^–1 and 45.46 mA·cm^–2, outperforming commercial Pt/C by factors of 21.8 and 11.4, respectively. In the practical DFAPEMFC device, the Pt/Ag@Bi₂Te₃ delivers a peak power density of 116.2 mW·cm^–2, indicating its application potential. Density functional theory calculations further confirm the electron-rich Pt active sites and higher energy efficiency for the complete dehydrogenation direct pathway. This study provides a new strategy for preparing highly efficient FAOR catalysts for actual DFAPEMFCs.