Tin Active Sites Confined in Zeolite Framework as a Promising Shape‐Selective Catalyst for Ethylene Oxide Hydration
Xue Liu, Sen Liu, Tingyu Yan, Ningzhao Shang, Huiliang Li, Zheng Wang, Hao Xu, Peng Wu
Abstract
Abstract Shape‐selective stannosilicates have been post‐synthesized for the hydration of epoxide to diols. A simple acid treatment has been employed to remove extensively the interlayer double four ring units, converting the three‐dimensional (3D) UTL germanosilicate into a 2D layered IPC‐1P intermediate. Isomorphous incorporation of tetrahedrally coordinated Sn active centers was realized via solid‐liquid treatment of IPC‐1P with diammonium hexachlorostannate aqueous solution, which was accompanied by the spontaneous condensation of neighboring silica‐rich cfi layers upon calcination and structural construction of a 3D PCR structure. Sn‐PCR stannosilicates with tunable Sn contents were thus prepared. With Sn‐derived robust Lewis acidity confined in the intersecting 10‐ and 8‐ring channels, the Sn‐PCR (Si/Sn molar ratio of 77) catalyst served as a shape‐selective nanoreactor for the hydration of ethylene oxide (EO) into ethylene glycol (EG), exhibiting a remarkable EO conversion (99.5 %) as well as a steady EG selectivity (>98.4 %) at greatly reduced H 2 O/EO molar ratio and near‐ambient reaction temperature.