The development of efficient and stable Pt‐based catalysts is significant but challenging for fuel cells. Herein, Sn and Co elements are introduced into Pt to form PtCo‐PtSn/C heterostructure for enhancing the oxygen reduction reaction (ORR). Electrochemical results indicate that it has remarkable ORR intrinsic activity with a high mass activity (1,158 mA mg–1 Pt) at 0.9 V in HClO4 solution, which is 2.18‐, 6.81‐, and 9.98‐fold higher than that of PtCo/C, PtSn/C, and Pt/C. More importantly, the catalytic activity attenuation for PtCo‐PtSn/C is only 27.4% after 30 000 potential cycles, showing high stability. Furthermore, theoretical calculations reveal that the enhancement is attributed to charge transfer and the unique structure of PtCo‐PtSn/C heterostructure, which regulate the d‐band center of Pt and prevent non‐noble metals from further dissolution. This work thus opens a way to design and prepare highly efficient Pt‐based alloy catalysts for proton exchange membrane fuel cells.

Ammonia with a high hydrogen content is an ideal hydrogen carrier due to its mature storage and transport system. Ammonia electrooxidation is one of the most promising technologies for green and economic H2 production. However, ammonia oxidation reaction (AOR) is limited to a narrow potential window due to the slow kinetics and the competitive adsorption between the reactant and Had/OHad on active sites. Herein, an ultra-small PtPb alloy nanocatalyst is synthesized for AOR by the facile one-step solvothermal method. Experimental results demonstrate that the electronic structure of Pt is regulated by the introduction of Pb, inhibiting the competitive adsorption on Pt sites. Therefore, it exhibits improved AOR activity with a peak current density of 191.2 mA mg–1 Pt at 10 mV s–1, which is 1.97 times that of Pt/C. The good performance is attributed to the high hydrogen evolution overpotential property of Pb and the strong p–d electron interaction of PtPb, which effectively modulates the adsorption/desorption of intermediates at the Pt site. Hence, this work proposes a simple and effective strategy for designing efficient AOR catalysts, promoting the development of H2 production by AOR.