The influence of composition on the functionality of hybrid CuO–ZnO–Al2O3/HZSM-5 for the synthesis of DME from CO2 hydrogenation |
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Authors: | Yubing Hu Yajing Zhang Jie Du Chunyan Li Kangjun Wang Lidong Liu Xinrui Yu Kai Wang Nan Liu |
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Institution: | College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang 110142 PR China, +86-24-89383902 |
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Abstract: | A series of CuO–ZnO–Al2O3/HZSM-5 hybrid catalysts with different Cu/Zn ratios and disparate Al2O3 doping were prepared and characterized by XRD, BET, H2-TPR, NH3-TPD and XPS techniques. The optimal Cu/Zn ratio is 7 : 3, and the introduction of a suitable amount of Al2O3 to form hybrid catalysts increased the BET specific area and micropore volume, facilitated the CuO dispersion, decreased the CuO crystallite size, increased the interaction between CuO and ZnO, enhanced the number of weak acid sites, altered the copper chemical state and improved the catalytic performance consequently. The highest CO2 conversion, DME selectivity and DME yield of 27.3%, 67.1% and 18.3%, respectively, were observed over the CZA7H catalyst. The suitable temperature of 260 °C and the appropriate space velocity of 1500 h−1 for one-step synthesis of dimethyl ether (DME) from carbon dioxide (CO2) hydrogenation were also investigated. The 50 h stability of the CZA7H catalyst was also tested.The introduction of Al2O3 increased the number of weak acid sites, altered the copper chemical state and improved the catalytic performance and stability consequently. |
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