Evolving top-down approaches for single-atom catalysis: synthesis and specialized applications

Abstract

Single-atom catalysts (SACs) exhibit exceptional performance across diverse catalytic reactions and can be synthesized through both bottom-up and top-down strategies. Among these, the top-down strategy, where bulk metals or nanoparticles are converted into isolated metal atoms, offers distinct advantages, including enhanced metal–support interactions, intrinsic cost-effectiveness and catalyst upcycling. This review summarizes recent breakthrough in top-down synthesis methodologies, covering fundamental synthetic techniques (e.g., thermal treatment, abrasion, light/electric energy-driven methods) and their specific applications in various catalytic systems. Notably, top-down strategies show strong adaptability under practical reaction environments, enabling functions such as the regeneration of spent catalysts and kinetic restructuring in response to reaction conditions. Overall, this review aims to promote a deeper understanding of top-down synthetic principles, accelerate their industrial implementation, and unlock the full potential of SACs.