Shape-controlled synthesis of Pd nanotetrahedrons with Pt-doped surfaces for highly efficient electrocatalytic oxygen reduction and formic acid oxidation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-01, Vol.451, p.138786, Article 138786
• Main Authors: Luo, Liuxuan, Tan, Zehao, Fu, Cehuang, Xue, Rui, Cheng, Xiaojing, Bi, Tianzi, Zhao, Lutian, Guo, Yangge, Cai, Xiyang, Yin, Jiewei, Shen, Shuiyun, Zhang, Junliang
• Format: Article
• Language: English
• Subjects: Formic acid oxidation reaction; Oxygen reduction reaction; Palladium; Platinum; Shape-controlled synthesis; Surface doping
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.138786

Trioctylphosphine is firstly introduced in the CO-assisted solvothermal method to synthesize uniform Pd nanotetrahedrons, which are surface-doped with Pt atoms for highly efficient electrocatalytic oxygen reduction and formic acid oxidation. [Display omitted] •TOP is firstly introduced in the CO-assisted Pd shape-controlled synthetic method.•Small-sized, uniform, and highly selective Pd NTs are obtained via this method.•Pd NTs are surface-doped with Pt atoms by the modified Pt2+ galvanic replacement.•Pd/SDPt NTs exhibit highly efficient ORR and FAOR electrocatalytic performance.•The structure-function relations are studied both experimentally and theoretically. Increasing the accessible active sites and especially improving the intrinsic activity are two major effective strategies for enhancing the electrocatalytic activity of nanomaterials. Accordingly, through the trioctylphosphine (TOP)-based CO-assisted solvothermal method and the small-amount Pt2+ galvanic replacement, highly uniform Pd nanotetrahedrons (NTs) with Pt-doped surfaces are synthesized and supported onto carbon black. Comprehensive experimental and theoretical analyses reveal that, owing to the Pt surface-doped (SD) nanostructure, the conformal formation of surface Pt {111} facets, as well as the strain and electronic effects induced by the Pd–Pt alloy structure, Pd/SDPt NTs/C exhibits much better electrocatalytic performance than Pd NTs/C, commercial Pd/C, and Pt/C toward both oxygen reduction and formic acid oxidation reactions, showing greatly improved metal utilization and area/mass-specific activity. This study develops a high-performance bifunctional electrocatalyst, and firstly introduces TOP as the easy-removable surface-energy adjuster for the Pd shape-controlled synthesis, which may be further expanded to other metals and shapes.