Mechanochemical preparation of single atom catalysts for versatile catalytic applications: A perspective review

A mechanochemical ball milling process will spontaneously generate strong shear force and a high local temperature, which will reconstruct the chemical bonds of materials and renovate the surface chemistry characteristics. The ball milling method is a simple and robust strategy to large scale synthesize nanomaterials, and it can also be used to synthesize single atom catalysts (SACs). In this review, we systematically summarized the methodology and principle of ball milling strategy for the preparation of SACs for the first time, which include the solvent-assisted ball-milling strategy, solvent-free ball-milling strategy, and ball-milling abrasion-thermal atomization joint strategy. At the same time, we also summarized the latest progress in heterogeneous catalysis applications of SACs prepared by mechanical ball milling strategy (including thermocatalysis, photocatalysis and electrocatalysis). The challenges and prospects of the ball milling-derived SACs in practical industrial production and application are pointed out as well. Admittedly, the mechanochemical construction of SACs has become a hot research field in sub-nanometer manufacturing and heterogeneous catalysis.