Advancing Benzene-to-Phenol Synthesis via Single-Atom Catalysts: Coordination Engineering and Mechanism Insights

Direct benzene oxidation to phenol (BOP) using H 2 O 2 represents a sustainable route to chemical manufacturing, yet it is compromised by the inertness of the aromatic C–H bond and overoxidation-induced selectivity loss. Single-atom catalysts (SACs), featuring high valence and electron deficiency, disrupt the aromatic conjugated structure while enabling precise oxygen insertion. Despite breakthrough studies, the field lacks a systematic framework connecting atomic-level design principles with mechanistic understanding. This review provides the first comprehensive synthesis of transition metal SACs for H 2 O 2 -driven BOP, emphasizing four pillars: (i) the development of tailored synthetic strategies, (ii) support engineering that modulates electronic configurations, (iii) coordination environment manipulation that governs d-band center positions, and (iv) operando characterization coupled with DFT calculations unraveling dynamic O*═M═O* intermediate evolution. Defect-mediated active site construction, d-band hybridization, and dual-heteroatom coordination dictate H 2 O 2 activation and phenol selectivity. By establishing correlations between electronic structures and catalytic performance, this work provides predictive design principles for next-generation catalysts that hold promise for advancing selective phenol synthesis toward industrial relevance.