Design of earth-abundant amorphous transition metal-based catalysts for electrooxidation of small molecules: Advances and perspectives

Electrochemical oxidation of small molecules (e.g., water, urea, methanol, hydrazine, and glycerol) has gained growing scientific interest in the fields of electrochemical energy conversion/storage and environmental remediation. Designing cost-effective catalysts for the electrooxidation of small molecules (ESM) is thus crucial for improving reaction efficiency. Recently, earth-abundant amorphous transition metal (TM)-based nanomaterials have aroused souring interest owing to their earth-abundance, flexible structures, and excellent electrochemical activities. Hundreds of amorphous TM-based nanomaterials have been designed and used as promising ESM catalysts. Herein, recent advances in the design of amorphous TM-based ESM catalysts are comprehensively reviewed. The features (e.g., large specific surface area, flexible electronic structure, and facile structure reconstruction) of amorphous TM-based ESM catalysts are first analyzed. Afterward, the design of various TM-based catalysts with advanced strategies (e.g., nanostructure design, component regulation, heteroatom doping, and heterostructure construction) is fully scrutinized, and the catalysts' structure-performance correlation is emphasized. Future perspectives in the development of cost-effective amorphous TM-based catalysts are then outlined. This review is expected to provide practical strategies for the design of next-generation amorphous electrocatalysts.