Synergistic Cu–OH and zeolite confinement in Cu/MCM-22 for benzaldehyde-mediated Mukaiyama epoxidation of long-chain α-olefins

作者：Hongying Chang, Ziyu Zhou, Peng He, Kun Zhang, Yujie Xie, Xiangjie Zhang, Tao Yan, Min Zhang, Gaolei Qin, Huaming Hou, Yanyan Chen, Jianguo Wang, Zhi Cao · 发表于：National Science Review · 年份：2025 · DOI：10.1093/nsr/nwaf502 · 被引用次数：2 · 研究领域：Mesoporous Materials and Catalysis、Catalytic Processes in Materials Science、Zeolite Catalysis and Synthesis

ABSTRACT The Mukaiyama epoxidation of olefins, leveraging molecular oxygen and aldehydes to generate epoxides, is a cornerstone of sustainable synthesis but is hindered by compromising epoxide selectivity and aldehyde coupling efficiency due to the high reactivity of acylperoxy radicals. Here, we report a Cu/MCM-22 catalyst that synergistically integrates Cu–OH active sites with zeolite confinement to achieve exceptional selectivity and efficiency in the aerobic epoxidation of long-chain linear α-olefins. Comprehensive characterization, including transmission electron microscopy, X-ray absorption spectroscopy and Fourier-transform infrared spectroscopy, confirms atomically dispersed Cu2+ ions within MCM-22’s framework, enabling benzaldehyde activation via Cu2+/Cu+ redox cycling and H2O formation. Electron paramagnetic resonance and density functional theory (DFT) studies reveal that the confined pores of MCM-22 stabilize acylperoxy radicals, suppressing undesired pathways and promoting epoxide formation. Catalytic evaluations demonstrate 97% conversion and 90% selectivity for 1-undecene epoxidation, which was further improved to 99% selectivity by deactivating the Cu sites on the zeolite external surface, resulting in a roughly 3-fold increase in aldehyde coupling efficiency and significantly outperforming unconfined Cu/Al2O3 and Cu/SiO2. Kinetic analyses and DFT calculations highlight reduced energy barriers (84 kJ·mol−1) for benzaldehyde activation and enhanced chemoselecti...