Hydrophobic Microenvironment on Cu–Co Oxides for Dual Promotion of Mass Transfer and Electronic Regulation in Alkyl Aromatic Oxidation

In heterogeneous catalysis, the synergistic regulation of interfacial mass transfer efficiency and intrinsic catalytic activity is a key challenge for enhancing selective oxidation performance. This study constructed a hydrophobic microenvironment by grafting hexadecyl chains onto mesoporous Cu-Co oxide surfaces. In the solvent-free ethylbenzene oxidation reaction, the conversion rate increased from 40.5% to 67.8%, while maintaining 95.2% acetophenone selectivity and good cycling stability. The hydrophobic modification not only enriches reactants and excludes water byproducts to optimize mass transfer but also induces significant electronic restructuring. Spectral characterization and theoretical calculations reveal that the hydrophobic chains promote directional electron transfer from Co to Cu, enhance the covalency of Cu-O-Co units, and reduce the oxygen vacancy formation energy by 0.418 eV. This work provides an interfacial engineering strategy for the design of high-performance heterogeneous catalysts.