Self-Assembly Intermetallic PtCu<sub>3</sub> Core with High-Index Faceted Pt Shell for High-Efficiency Oxygen Reduction
Xue Zhang, Xiaokang Liu, Dan Wu, Longfei Hu, Huijuan Zhang, Zhiguo Sun, Shiting Qian, Zhiyuan Xia, Qiquan Luo, Linlin Cao, Jinlong Yang, Tao Yao
Abstract
Rational design of well-defined active sites is crucial for promoting sluggish oxygen reduction reactions. Herein, leveraging the surfactant-oriented and solvent–ligand effects, we develop a facile self-assembly strategy to construct a core–shell catalyst comprising a high-index Pt shell encapsulating a PtCu 3 intermetallic core with efficient oxygen-reduction performance. Without undergoing a high-temperature route, the ordered PtCu 3 is directly fabricated through the accelerated reduction of Cu 2+, followed by the deposition of the remaining Pt precursor onto its surface, forming high-index steps oriented by the steric hindrance of surfactant. This approach results in a high half-wave potential of 0.911 V versus reversible hydrogen electrode, with negligible deactivation even after 15000-cycle operation. Operando spectroscopies identify that this core–shell catalyst facilitates the conversion of oxygen-involving intermediates and ensures antidissolution ability. Theoretical investigations rationalize that this improvement is attributed to reinforced electronic interactions around high-index Pt, stabilizing the binding strength of rate-determining OH ads species.