Maximizing the Catalytic Performance of Pd@AuxPd1−x Nanocubes in H2O2 Production by Reducing Shell Thickness to Increase Compositional Stability

• Published in: Angewandte Chemie (International ed.) Vol. 60; no. 36; pp. 19643 - 19647
• Main Authors: Zhang, Yu, Lyu, Zhiheng, Chen, Zitao, Zhu, Shangqian, Shi, Yifeng, Chen, Ruhui, Xie, Minghao, Yao, Yao, Chi, Miaofang, Shao, Minhua, Xia, Younan
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2021; Wiley
• Edition: International ed. in English
• Subjects: alloys; Chemical composition; Electrocatalysts; Gold; Hydrogen peroxide; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Nanocrystals; noble metals; Optimization; Palladium; Selectivity; shell; Shells; surface stability; Surface structure; Thickness
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202105137

We report a simple route based upon seed‐mediated growth to the synthesis of Pd@AuxPd1−x (0.8≤x≤1) core–shell nanocubes. Benefiting from the well‐defined {100} facets and an optimal Au/Pd ratio for the surface, the nanocubes bearing a shell made of Au0.95Pd0.05 work as an efficient electrocatalyst toward H2O2 production, with high selectivity of 93–100 % in the low‐overpotential region of 0.4–0.7 V. When the Au0.95Pd0.05 alloy is confined to a shell of only three atomic layers in thickness, the electrocatalyst is able to maintain its surface structure and elemental composition, endowing continuous and stable production of H2O2 during oxygen reduction at a high rate of 1.62 mol g(Pd+Au)−1 h−1. This work demonstrates a versatile route to the rational development of active and durable electrocatalysts based upon alloy nanocrystals. We address the issue of surface segregation of alloy electrocatalysts by conformally depositing the alloy as an ultrathin shell on shape‐controlled nanocrystals. As a result of the optimized Au/Pd ratio in the shell and highly active {100} facets, we obtain Pd@Au0.95Pd0.05 nanocubes with superb performance in electrochemical H2O2 production.