Electron-rich CuOx@Al2O3 Catalyst for Sustainable O2 Activation in Fenton-Like Reactions

Abstract

Molecular oxygen (O2) activation is pivotal in advancing green chemistry and catalysis, addressing processes such as energy conversion and environmental remediation. However, the inherent inertness of the O2 necessitates highly efficient catalysts. In this study, an electron-rich CuOx@Al2O3 catalyst with high metal loading and dispersion was synthesized via the ion-exchange inverse-loading method. The novel CuOx@Al2O3 significantly enhanced O2 activation due to the accelerated Cu⁰ → Cu⁺ → Cu²⁺ redox cycle, achieving the 85% chlorobenzene removal in Fenton-like reaction. This is substantially higher than the chlorobenzene removal observed with conventional CuOx/Al2O3 (45%). Experiments and density functional theory (DFT) calculations revealed that Cu-Cu sites over CuOx@Al2O3 greatly facilitated charge transfer, weakened O-O bonds, and promoted synergistic O2 and H2O2 activation to produce ^•OH and O2^•-, thereby enhancing oxidants utilization efficiency. This study provides a sustainable pathway for pollutant degradation by achieving O2 activation and offers valuable insights for designing advanced Cu-based catalysts in green oxidation processes and environmental remediation.