Phosphorus-Doping Drives the Formation of a Pt-Skin@PtFe Alloy Catalyst With Modulated d-Band Center for Oxygen Reduction

en This link goes to a English section zh This link goes to a Chinese section Platinum (Pt)-based catalysts are crucial for the commercialization of hydrogen/metal air batteries, but they suffer from Pt scarcity, high cost, and nanoparticle dissolution/agglomeration, mainly leading to performance degradation. We address this by synthesizing a PtFe alloy catalyst (PtFe–PA–NC) via a phytic acid (PA) assisted pyrolysis strategy, featuring Pt-skin-coated PtFe alloy nanoparticles on hierarchically porous N-doped carbon (NC). PA treatment simultaneously enhances the support's surface area and pore structure for better mass transport, and incorporates P into the carbon framework via P–C bonds. It can induce charge delocalization, regulating the electronic structure of PtFe alloys and strengthening Pt–Fe coupling. The Pt-skin suppresses Fe dissolution, whereas the PtFe core optimizes oxygen reduction reaction (ORR) intermediate adsorption (e.g., *OH). Theoretical calculations confirm that the Fe atom adjusts the d-band center of the Pt atom, intensifying oxygen binding and shifting the rate-determining step. Electrochemically, PtFe–PA–NC achieves a half-wave potential of 0.85 V and retains 95.8% of specific energy density after more than 140 h in zinc-air batteries. In alkaline fuel cells, it delivers a peak power density of 508 mW cm −2 at an ultralow Pt loading (0.017 mg cm −2 ), approximately twice that of 5 wt% Pt/C (0.025 mg cm −2 ). This work showcases synergistic electronic and interfacial regulation through heteroatom doping and alloying, promoting high-performance hydrogen/metal air batteries. 摘要 en This link goes to a English section zh This link goes to a Chinese section 铂基催化剂是氢/金属空气电池商业化的关键,但铂资源稀缺、成本高昂且纳米颗粒易溶解/团聚 , 是导致其性能衰减的主要原因。为此 , 本论文通过植酸(PA)辅助热解策略合成了一种 PtFe合金催化剂(PtFe–PA–NC) , 其结构为: Pt 壳层包覆的PtFe合金纳米颗粒负载于分级多孔氮掺杂碳(NC)载体上。通过植酸处理过程可同时实现了两个效果 : 一是提升了载体的比表面积与孔结构, 优化了传质效率 ; 二是通过 P–C 键将磷引入碳骨架,诱导电荷离域 , 从而调控 PtFe 合金的电子结构、强化 Pt–Fe 耦合作用。其中, Pt 壳层可抑制 Fe 的溶解, 而 PtFe 核则能优化氧还原反应(ORR)中间产物(如 * OH)的吸附行为。理论计算表明: Fe 原子可调节 Pt 原子的 d 带中心, 增强氧的结合作用并改变反应的决速步。电化学测试表明: 在锌空气电池中, PtFe–PA–NC 的半波电位达 0.85 V, 且在 140 h 以上的运行后仍保持 95.8% 的能量密度; 在碱性燃料电池中, 当 Pt 载量低至 0.017 mg cm −2 时, 其峰值功率密度达 508 mW cm −2 , 约为商用 5 wt% Pt/C (载量为 0.025 mg cm −2 ) 的两倍。本研究工作通过杂原子掺杂与合金化实现了电子结构与界面的协同调控, 为高性能氢/金属空气电池的开发提供了新思路。