Top-down synthetic strategies toward single atoms on the rise

Summary

The pursuit of high performance in specific conditions motivated the grand development of synthetic methodologies for single-atom catalysts (SACs) in various research fields. In general, the existing methods for SACs could be simply classified into two main types—"bottom-up" and "top-down". The former was extensively explored and well documented elsewhere, whereas the latter is just on the rise. As it is, there is currently a lack of systematic overview for the top-down synthetic strategies to SACs. In this review, the rising top-down strategies are summarized in detail, including various thermo- and electrochemistry-based methods as well as other new protocols, based on the difference of metal-support interactions and energy input required during the atomization of bulk or micro- or nanoscale metal precursors. The introduction of the top-down synthetic strategies herein is believed to not only help establish the complete available methodology for task-specific SACs, but also contribute to the in-depth insights into the deactivation and regeneration mechanism of spent, supported metal catalysts for potential industrial application.