Hollow CeO2 Nanosphere-Supported Copper Catalysts with Abundant Cu0/Cu+ Interfaces for Efficient Hydrogenation of Cyclohexyl Acetate to Cyclohexanol

Abstract

Cyclohexanol, as a key intermediate in the synthesis of nylon, faces critical issues in traditional production processes, such as low single-pass conversion and copper-based catalysts easily aggregating and deactivating. This study prepares hollow ceria nanosphere-supported copper catalysts (Cu/CeO2–HS) via a solvothermal method, calcination, and hydrogen reduction for the efficient hydrogenation of cyclohexyl acetate to cyclohexanol. Systematic characterization indicates that CeO2 has abundant oxygen vacancies, which can effectively stabilize the Cu+/(Cu0+Cu+) ratio. The hollow structure further improves the dispersion of active components, enhancing mass transfer. Highly dispersed Cu nanoparticles with surface-exposed Cu+ species form interfacial Cu–O–Ce sites, preventing aggregation and synergistically enhancing the activation of C═O bonds in cyclohexyl acetate. Under optimal conditions (250 °C, 3 MPa H2, 2 h), the optimal catalyst achieves 99.9% cyclohexyl acetate conversion with 97.5% selectivity to cyclohexanol. Importantly, it maintains the 99.8% conversion and 96.7% selectivity over five consecutive cycles without significant structural or chemical state change, demonstrating robust stability. This work addresses both the limitations of traditional processes and the issue of easy deactivation of copper-based catalysts by constructing a hollow structure and enhancing the interfacial interaction between Cu species and CeO2, providing a reliable catalytic solution for the green and efficient industrial production of cyclohexanol.