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

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 tri-octylphosphine (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/Pt-SD 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.