Strain-Controlled Intermetallic PtZn Nanoparticles via N-Doping Propel Highly Efficient Oxygen Reduction Electrocatalysis
Linjie Zhang, Xianghong Li, Yiqing Chen, Hsiao‐Tsu Wang, Yuhui Chen, Kuan Hung Chen, Yu‐Cheng Shao, Wenlie Lin, Chih‐Wen Pao, Hua Wang, W. F. Pong, Jun Luo, Lili Han
Abstract
Targeting high-performance yet cost-effective Pt-based catalysts with low Pt usage and high Pt utilization remains a big challenge in the oxygen reduction reaction (ORR) electrocatalysis. In this work, we demonstrate delicate engineering of strain control via N-doping in ordered PtZn intermetallic nanoparticles supported on N-doped carbon (PtZnN/NC). Benefiting from the ameliorated compressive strain and consequently greatly optimized electronic structures, PtZnN/NC displays ultrahigh ORR activity and durability in both acidic and alkaline media, with respective high mass activities of 297.5 and 80.7 A g Pt –1 at 0.9 V RHE, exceeding those of benchmark Pt/C by 8.3- and 2.8-folds. Theoretical calculations reveal that the N-doping effectively lowers the d-band center of PtZnN, resulting in loose binding of *OH on the PtZnN surface, which facilitates the potential-determining step with a reduced energy barrier. This work successfully offers strategic guidance for strain equilibration in alloys via N-doping toward the rational design of advanced electrocatalysts.