| Autor: |
Zhao, Taotao, Shen, Chenyang, Liu, Yuchi, Liu, Gui, Qian, Xiaofeng, He, Qiang, Mei, Feifei, He, Yu, Guo, Xiangke, Xue, Nianhua, Liu, Xi, Ding, Weiping |
| Zdroj: |
Catalysis Science & Technology; 2024, Vol. 14 Issue: 8 p2166-2177, 12p |
| Abstrakt: |
We report here a bifunctional catalyst MoSx@H-Beta for highly selective conversion of CO2to C2–6hydrocarbons. The catalyst is prepared using a two-step solid reaction method. Firstly, MoOx@H-Beta, with MoOx+clusters at the exchangeable site of the zeolite, is obtained by sublimating and reacting MoO3with zeolitic H+sites during heating. Then, MoOx@H-Beta is converted into MoSx@H-Beta through a vulcanization reaction, by heating the mixture of MoOx@H-Beta and sulphur powder in flowing 5 vol% H2/N2. During the vulcanization of molybdenum oxide clusters, the zeolitic H+sites are recovered. Two types of active sites, i.e., molybdenum sulfide clusters and the zeolitic H+sites, are intimately encapsulated in channels of the MoSx@H-Beta catalyst. Over the catalyst, more than 75% of selectivity to C2–6hydrocarbons in organic products at ∼13% of CO2conversion is obtained under the optimal reaction conditions of 300 °C, 4 MPa, CO2/H2= 1/3, and 1600 mL g−1h−1. The characterization results indicate that CO2is firstly hydrogenated into intermediate CH3OH over the MoSxsites, which is subsequently converted into C2–6hydrocarbons over the adjacent Brønsted acid sites in channels of H-Beta zeolite. The MoSxclusters are highly dispersed and occupied in channels of H-Beta zeolite, exhibiting an excellent stability during 200 h on stream. The cooperative mechanism between molybdenum sulfide clusters and Brønsted acid sites of H-Beta zeolite constitutes the nature of a bifunctional catalyst, demonstrated by theoretical calculations, well accounting for its high catalytic performance. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
