The structure-performance relationships in active center size-dependent Fenton-like catalysis: From nanoparticles to single atoms

Compared to nanocluster catalysts (NCCs) and nanoparticle catalysts (NPCs), single-atom catalysts (SACs) with isolated spatial sites and unique electronic structures generally demonstrate superior activity, selectivity, and stability. However, the correlation between the size of catalytic centers (ranging from nanoparticles to the atomic scale) and their performance in Fenton-like reactions remains unclear. In this review, we systematically outline the scale-regulated synthesis from NPCs to SACs, summarize the relationship of catalytic performance and mechanism to the active center scale, and emphasize the pivotal role played by the coordination microenvironment in dictating catalytic performance. Importantly, our analysis delves into the impact of the catalytic center scale on performance at the atomic level, specifically comparing isolated metal sites and metal-metal interactions, transcending the conventional consideration of active site density variation. To conclude, we highlight the challenges and future directions for research on structure-performance relationships, which are indispensable for the development of high-performance SAC architectures.