Constructing Mn-O-Ni Bridges for Enhanced Aerobic Oxidation of Ethylbenzene via Local Electronic Modulation.

Developing efficient and cost-effective catalysts for the solvent-free oxidation of ethylbenzene (EB) using molecular oxygen remains a key challenge. This work demonstrates that Mn-doped Ni(OH)2 acts as a highly active and selective catalyst for this transformation. Comprehensive characterization reveals that Mn incorporation not only induces lattice contraction and generates abundant oxygen vacancies (OV), but also creates Mn-O-Ni bridges that drive electron transfer from Ni to Mn, thereby optimizing the electronic structure of the active sites. This dual electronic-structural modulation strengthens EB adsorption and lowers the apparent activation energy to 38.8 kJ·mol-1, significantly less than that of pure Ni(OH)2 (54.1 kJ·mol-1). DFT calculations further reveal Mn doping-induced localized electronic perturbations that enhance substrate binding. Under optimized conditions, Mn-Ni(OH)2 achieves 75.5% EB conversion with 90.9% selectivity to acetophenone (AP) in 6 h, markedly outperforming the undoped analogue (36.7% conversion). This study highlights electronic engineering via heteroatom doping as a powerful strategy for activating transition-metal hydroxides in selective oxidation catalysis.