General Synthesis of Transition-Metal-Based Carbon-Group Intermetallic Catalysts for Efficient Electrocatalytic Hydrogen Evolution in Wide pH Range

摘要

Alloying is a well-accepted strategy for modulating the electronic structures of catalyst materials. Compared to disordered solid-solution alloys, intermetallic compounds feature ordered atomic arrangements and provide a unique platform with a rich and diverse resource to study the relationships among chemical composition, atomic structure, electronic structure, and properties. Unfortunately, it is still challenging to synthesize the nanostructures of intermetallic compounds for catalysis research. In this study, a series of intermetallic silicides (PtSi, RhSi, Ru2Si3, IrSi), germanide (Ru2Ge3), and stannides (Ru3Sn7, IrSn2, PdSn3, PdSn2) are rationally designed and constructed through a facile molten-salt-assisted route. As an example, the PtSi not only shows highly desirable electrocatalytic properties for the hydrogen evolution reaction (HER) with low overpotentials of 22, 38, and 66 mV at a current density of 10 mA cm(-2) in acidic, alkaline, and neutral media, respectively, but exhibits superior durability, as well as 97 faradic efficiency. The theoretical calculations suggest that the introduction of Si to Pt could weaken the binding energy between Pt and H atoms, which further facilitates the hydrogen generation during the HER process. Further, the findings inspired the authors to develop other kinds of metal-based carbon-group intermetallic phases with excellent activity in the HER and beyond.