Ti Single Atom Enhancing Pt‐Based Intermetallics for Efficient and Durable Oxygen Reduction

Abstract The insufficient durability of Pt‐based catalysts and the sluggish kinetics of oxygen reduction reaction (ORR) is hampering the development of proton exchange membrane fuel cells (PEMFCs) for commercialization. Herein, a single atom Ti‐modified activated nitrogen‐doped porous carbon (Ti‐a‐NPC) is designed to equalize O 2 ‐activation/ * OH‐removal through regulating the charge rearrangement of ultra‐small L1 2 ‐Pt 3 Co for efficient and durable oxygen reduction. The Ti single‐atom modified in the surface/pore of Ti‐a‐NPC can anchor the Pt‐based intermetallic nanoparticles (NPs) not only guarantees Pt‐based intermetallics’ ultra‐fine size (≈2.62 nm) but also maintains Pt‐based intermetallics during ORR process. The enhanced catalyst (L1 2 ‐Pt 3 Co/Ti‐a‐NPC) achieves 11‐fold mass activity (1.765 A mg Pt −1 ) compared to commercial Pt/C. Notably, after 30 000 cycles of accelerated durability tests, the mass activity of the L1 2 ‐Pt 3 Co/Ti‐a‐NPC only decreased by 3.7%, while that of commercial Pt/C decreased by 37.1%. Rationalized by theoretical simulation, the introduction of Ti atoms can form charge channels between L1 2 ‐Pt 3 Co NPs and Ti‐a‐NPC, accelerating the charge transfer in the ORR process. Furthermore, the charge of L1 2 ‐Pt 3 Co will accumulate to Ti atoms and buffer the electron transfer of L1 2 ‐Pt 3 Co to the N atoms, thus optimizing the adsorption performance of the active site to the oxygen‐containing intermediate and improving the intrinsic activity of the catalyst.