1. Enhancing methanol selectivity of commercial Cu/ZnO/Al2O3 catalyst in CO2 hydrogenation by surface silylation.
- Author
-
Cui, Xiaojing, Liu, Yequn, Yan, Wenjun, Xue, Yanfeng, Mei, Yangang, Li, Jiamei, Gao, Xiaoqing, Zhang, He, Zhu, Shanhui, Niu, Yulan, and Deng, Tiansheng
- Subjects
- *
COPPER , *SILYLATION , *ALUMINUM oxide , *WATER gas shift reactions , *CARBON dioxide - Abstract
Suppressing reverse water-gas-shift (RWGS) reaction is high desirable but challenging and underdeveloped for Cu/ZnO catalysts, particularly for commercial Cu/ZnO/Al 2 O 3 catalysts. Different from the current methodologies to reduce RWGS reaction, we report a simply surface silylation method for efficiently minimizing RWGS reaction over a commercial Cu/ZnO/Al 2 O 3 catalyst. This method suppresses STY CO (Space-time yield) from 97.4 to 0.7 g CO ·kg cat −1·h−1, improving STY MeOH from 20.2 to 39.9 g MeOH ·kg cat −1·h−1 and methanol selectivity from 15.1 to 92.9 mol%. The combination of characterization methods and density functional theory calculations provide insight into the suppressing mechanism of surface silylation on catalyst. A hydroxyl (on ZnO)-promoted RWGS reaction cycle is discovered, which can be efficiently inhibited by the consuming of hydroxyls via surface silyation. Our results provide a way to regulate RWGS reaction on Cu/ZnO-based catalysts and are expected to the further use of silylation strategy to tune the interconversion of CO and CO 2 via RWGS/WGS reaction on hydrogenation catalysts. [Display omitted] • Surface silylation suppresses RWGS reaction on Cu/ZnO/Al 2 O 3 for CO 2 hydrogenation, promoting S CH3OH from 15.3 to 92.9 mol%. • A Zn-OH promoted RWGS mechanism is found, i.e., H spillover from Cu to the reactants via the Zn-OHs boosts RWGS reaction. • Consuming hydroxyls via the surface silylation inhibits the H spillover and further RWGS reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF