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K-doped CuO/ZnO with dual active centers of synergism for highly efficient dimethyl carbonate synthesis |
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| Authors: | Han Han Xue Ye Jie Yao Xinhua Gao Jinghao Yu Lisheng Guo Jie Li |
| Affiliation: | 1. School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China
Contribution: Conceptualization (equal), Formal analysis (equal), Investigation (equal), Writing - original draft (lead);2. School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China;3. Department of Applied Chemistry, School of Engineering, University of Toyama, Toyama, Japan;4. State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, Ningxia University, Yinchuan, China Contribution: Data curation (equal);5. Baeight Pty Ltd., Canberra, Australian Capital Territory, Australia Contribution: Validation (equal);6. School of Chemistry and Chemical Engineering, Anhui University, Hefei, China Contribution: Resources (equal), Validation (equal) |
| Abstract: | The application of heterogeneous catalysts in dimethyl carbonate (DMC) synthesis from methanol is hindered by low activation efficiency of methanol to methoxy intermediates (CH3O*), which is the key intermediate for DMC generation. Herein, a catalyst of alkali metal K anchored on the CuO/ZnO oxide is rationally designed for offering Lewis acid–base pairs as dual active centers to improve the activation efficiency of methanol. Characterizations of CO2-TPD, NH3-TPD, XPS, and DRIFTS revealed that the addition of Lewis base K observably boosted the dissociation of methanol and combined with Lewis acid CuO/ZnO oxide to adsorb the formed CH3O* stably, thus synergistically promoted the transesterification. Finally, the CuO/ZnO-9%K2O catalyst exhibited the optimal catalytic activity, achieving a high yield of 74.4% with an excellent selectivity of 98.9% for DMC at a low temperature of 90°C. The strategy of constructing Lewis acid–base pairs provides a reference for the design of heterogeneous catalysts. |
| Keywords: | activation and catalysis of methanol copper–zinc–potassium mixed oxides dimethyl carbonate transesterification |