Promoted selective oxidation of ethylbenzene in liquid phase achieved by hollow CeVO₄ microspheres

Herein, we developed a series of CeVO₄ samples with hierarchical hollow microsphere-like structure obtained at different calcination temperatures for the selective oxidation of ethylbenzene (EB) to acetophenone (AcPO) in the presence of TBHP. The optimized catalyst (CVO-500) exhibits a very high yield value of 95.0% (initial reaction rate of 49.4 mmol gcat^-1 h^-1) under the optimal reaction conditions. Importantly, the representative CVO-500 catalyst presents high stability, with the reaction performance well maintained after five consecutive uses. It has been indicated that the redox V⁵⁺/V³⁺ sites serve as the main active centers, while the electronic interaction and redox transformation between Ce and V facilitates the hopping of V⁵⁺/V³⁺ and the generation of oxygen vacancies. The bimetallic synergy between V and Ce thus endows the CVO-500 catalyst an excellent performance in the EB oxidation reaction. This work paves the way for the exploit of high-performance and cost-effective catalyst for the EB oxidation and beyond.