State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
School of Physical Science and Technology, Inner Mongolia University, Hohhot, 010021, China.
Angew Chem Int Ed Engl. 2023 Jun 5;62(23):e202302134. doi: 10.1002/anie.202302134. Epub 2023 Apr 28.
The harsh working environments of proton exchange membrane fuel cells (PEMFCs) pose huge challenges to the stability of Pt-based alloy catalysts. The widespread presence of metallic bonds with significantly delocalized electron distribution often lead to component segregation and rapid performance decay. Here we report L1 -Pt CuGa intermetallic nanoparticles with a unique covalent atomic interaction between Pt-Ga as high-performance PEMFC cathode catalysts. The L1 -Pt CuGa/C catalyst shows superb oxygen reduction reaction (ORR) activity and stability in fuel cell cathode (mass activity=0.57 A mg at 0.9 V, peak power density=2.60/1.24 W cm in H -O /air, 28 mV voltage loss at 0.8 A cm after 30 000 cycles). Theoretical calculations reveal the optimized adsorption of oxygen intermediates via the formed biaxial strain on L1 -Pt CuGa surface, and the durability enhancement stems from the stronger Pt-M bonds than those in L1 -PtCu resulted from Pt-Ga covalent interactions.
质子交换膜燃料电池（PEMFC）恶劣的工作环境对基于 Pt 的合金催化剂的稳定性提出了巨大挑战。广泛存在的金属键具有显著离域的电子分布，往往导致组分分离和性能迅速衰减。在这里，我们报告了具有独特的 Pt-Ga 共价原子相互作用的 L1 -PtCuGa 金属间化合物纳米粒子，作为高性能 PEMFC 阴极催化剂。L1 -PtCuGa/C 催化剂在燃料电池阴极中表现出优异的氧还原反应（ORR）活性和稳定性（质量活性=0.57 A mg 在 0.9 V，峰值功率密度=2.60/1.24 W cm 在 H -O /空气，在 30000 次循环后 0.8 A cm 的电压损失为 28 mV）。理论计算表明，通过 L1 -PtCuGa 表面形成的双轴应变优化了氧中间体的吸附，而耐久性的提高源于 Pt-Ga 共价相互作用导致的 Pt-M 键比 L1 -PtCu 中的更强。
