CuOx within a self-supported reduced graphene oxide film for the selective oxidation of styrene

Abstract

Cu²⁺ ions on the surface of Cu-based nanoparticles (NPs) act as active sites for various reactions, including olefin oxidation. However, conventional Cu-based catalysts commonly used in laboratory studies are macroscale and powdery. In this study, we successfully synthesized CuO NPs containing Cu²⁺ and oxygen vacancies occupied by hydroxyl groups and metallic Cu (CuOx NPs) through tert‑butylhydroperoxide (TBHP) treatment. These CuOx NPs were encapsulated within a self-supported reduced graphene oxide (rGO) film with a lamellar structure (Cu-V@rGO-film-x) via polyol reduction combined with a cast-drying process. Remarkably, even at a low catalyst dosage (0.75 mol % Cu), [email protected] demonstrated superior catalytic activity compared to conventional sample, achieving significantly higher styrene conversion (82.4 % vs. 30.0 %) by mitigating the aggregation of CuOx@rGO sheets. This indicates that the lamellar structure of Cu-V@rGO-film-x facilitates efficient mass transfer. Moreover, [email protected] exhibited excellent stability, maintaining catalytic activity over four recycling cycles without significant decline. This study presents a facile and controllable strategy for encapsulating CuOx NPs in macroscale thin films with a lamellar structure, offering broad applications in catalysis and providing a rational design methodology for easily recyclable heterogeneous catalysts.