251. Enhanced ethanol synthesis from CO2 hydrogenation over Fe and Na co-modified Rh/CeO2 catalysts.
- Author
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Ji, Shuangtao, Hong, Fei, Mao, Dongsen, Guo, Qiangsheng, and Yu, Jun
- Subjects
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CARBON dioxide , *CERIUM oxides , *CATALYSTS , *DISPERSION (Chemistry) , *ETHANOL , *SPECIES - Abstract
[Display omitted] • Fe and Na were found to be the most efficient promotors of Rh/CeO 2 catalyst for CO 2 hydrogenation to ethanol. • The optimized catalyst of 2Rh0.5Fe0.5Na/CeO 2 obtains a high ethanol selectivity of 29.8 % with a CO 2 conversion of 13.0 %. • The modification of Fe and Na promote the formation of Rh+ species, enhancing capacities of CO 2 adsorption and dissociation. • The Rh active sites synergized with Fe and Na can stabilize the adsorbed species of m-CO 3 2− and CO 3 H−. • The generation of HCOO*, CH 3 O* and CH 3 CH 2 O* intermediates promotes the ethanol formation. Rh catalyst is investigated as a strong candidate for CO 2 hydrogenation to ethanol, but it is still challenging because of the poor conversion efficiency. Here, by screening the promotors systematically and varying the amounts of components simultaneously, the optimized catalyst of 2Rh0.5Fe0.5Na/CeO 2 was found to highly efficient catalytic CO 2 hydrogenation to ethanol, giving a high ethanol selectivity of 29.8 % with a superior CO 2 conversion of 13.0 % at 250 °C, 3 MPa, and the ethanol productivity reached 116.7 mmol·g Rh −1·h−1. Characterization results revealed that the modification of Fe and Na, can promote the dispersion of Rh and the formation of Rh+ species, enhancing the capacities of CO 2 adsorption and dissociation. In situ DRIFT experiment illuminated that the Rh active sites synergized with Fe and Na can stabilize the adsorbed species of m-CO 3 2− and CO 3 H−, and promote the generation of HCOO* and CO* intermediates, which can be provided to couple with the CH x species, resulting in the high efficacy for ethanol synthesis from CO 2 hydrogenation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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