The Synergistic Action of Co, Cu and Ce Was Used to Achieve Efficient Aerobic Epoxidation of Styrene

Abstract

The precise embedding of metal species within specific sites of zeolite frameworks and their unique microenvironments exert fascinating influences on catalytic performance. Herein, we report the rational design of a highly efficient Co-Cu@CTS-1 catalyst through the strategic incorporation of Co, Cu, and Ce into TS-1 zeolite, where Ce is doped at silicon atomic sites while Co and Cu are encapsulated within the zeolite cages. Mechanistic investigations reveal that the synergistic interplay among Co, Cu, and Ce is pivotal for catalytic activity: Co facilitates molecular oxygen activation to generate reactive oxygen species (O⁻), while Ce(III) enhances oxygen vacancy concentration, significantly boosting styrene conversion. Moreover, the distinctive electronic interaction between Ce and Cu markedly improves the selectivity toward styrene oxide. The optimized Co-Cu@CTS-1 catalyst exhibits exceptional performance in the aerobic epoxidation of styrene, achieving a remarkable conversion of 78.11% with 87.31% epoxide selectivity under mild conditions (80 °C, 2 h). Furthermore, the catalyst demonstrates outstanding stability, retaining 68.21% conversion even after 20 reaction cycles, underscoring its superior resistance to metal sintering and long-term durability. This work provides valuable insights into the rational design of multifunctional zeolite catalysts through precise metal positioning and microenvironment modulation.

Graphical Abstract