Strain-Controlled Intermetallic PtZn Nanoparticles via N-Doping Propel Highly Efficient Oxygen Reduction Electrocatalysis

Abstract

Targeting high-performance yet cost-effective Ptbased 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.

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Boosting ORR Activity via Bidirectional Regulation of the Electronic Structure by Coupling MnO/Mn3O4 Composite Materials with N-Doped Carbon

“…The oxygen reduction reaction (ORR) is the cathodic process in green energy conversion devices such as fuel cells and metal–air batteries. − Platinum (Pt) and Pt-based catalysts are still considered state-of-the-art ORR electrocatalysts. However, the high price, shortage of resources, and instability of Pt have greatly limited its practical applications .…”