Heterostructured Pt-PbS Nanobelt Achieves Remarkable Direct Formic Acid Oxidation Catalysis

Developing efficient and CO-tolerant platinum (Pt)-based anodic catalysts is challenging for a direct formic acid fuel cell (DFAFC). Herein, we report heterostructured Pt-lead-sulfur (PtPbS)-based nanomaterials with gradual phase regulation as efficient formic acid oxidation reaction (FAOR) catalysts. The optimized Pt-PbS nanobelts (Pt-PbS NBs/C) display the mass and specific activities of 5.90 A mg_Pt^-1 and 21.4 mA cm^-2, 2.2/1.2, 1.5/1.1, and 36.9/79.3 times greater than those of PtPb-PbS NBs/C, Pt-PbSO₄ NBs/C, and commercial Pt/C, respectively. Simultaneously, it exhibits a higher membrane electrode assembly (MEA) power density (183.5 mW cm^-2) than commercial Pt/C (40.3 mW cm^-2). This MEA stably operates at 0.4 V for 25 h, demonstrating a competitive potential of device application. The distinctive heterostructure endows the Pt-PbS NBs/C with optimized dehydrogenation steps and resisting the CO poisoning, thus presenting the remarkable FAOR performance. This work paves an effective avenue for creating high-performance anodic catalysts for fuel cells and beyond.