کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6456078 1419841 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
CeCu composite catalyst for CO synthesis by reverse water-gas shift reaction: Effect of Ce/Cu mole ratio
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
CeCu composite catalyst for CO synthesis by reverse water-gas shift reaction: Effect of Ce/Cu mole ratio
چکیده انگلیسی


- The CeCu composite catalysts were prepared by hard template method for the RWGS reaction.
- Active Cu0 species and oxygen vacancies produced as confirmed via XRD and in situ XPS.
- The electronic effect boosted the adsorption performance of catalysts for CO2 and H2 molecules.
- The synergistic effect between active Cu0 and oxygen vacancies contributed to the high RWGS activity.

In this study, CeCu composite catalysts with different Ce/Cu mole ratios were prepared by a hard-template, and their performances in the reverse water-gas shift (RWGS) reaction were investigated. The catalysts were characterized using H2-TPR, XRD, in-situ XPS, AAS, CO2-TPD, and H2-TPD. The characterizations showed that the oxygen vacancies and active Cu0 species as active sites were formed in the CeCu catalysts by the H2 reduction at 400 °C. The synergistic effect of the surface oxygen vacancies and active Cu0 species enhanced catalytic activity of the studied CeCu composite catalysts. The electronic effect between Cu and Ce species boosted the adsorption and activation performances of the reactant CO2 and H2 molecules on the corresponding CeCu catalysts. The Ce1.1Cu1 catalyst demonstrated high stability and the highest CO2 conversion rate in the RWGS reaction, reaching 1.38 mmol gcat−1 min−1 at 400 °C. Its excellent catalytic performance in the RWGS reaction was related to the complete synergistic interaction between the active species via Ce3+-□-Cu0 (□: oxygen vacancy). A CeCu composite material is a superior catalyst for the RWGS reaction because of its high CO2 conversion, 100% CO selectivity, and high stability.

CexCuyO precursors can be effectively reduced at 400 °C because of the interactions of CuO with CeO2 to form surface oxygen vacancies and active Cu species. The synergistic effect of the surface oxygen vacancies with active Cu0 species can be realized, and the active Cu0 species can be stabilized because of the existence of Ce3+-□-Cu0 (□: oxygen vacancy) structure. The existence of Ce3+-□-Cu0 structure in the CexCuy catalyst can improve the electrons transfer to Ce from Cu to increase an electron-deficient state of the Cu species, which can enhance the adsorption performance of reactants CO2 and H2 molecules on the CexCuy catalysts. Consequently, the CO2 conversion on the Ce1.1Cu1 catalyst is significantly superior to those of the pure CeO2-δ and pure Cu0. And, the Ce1.1Cu1 catalyst can maintain a long-time stability for the CO2 RWGS reaction.156

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of CO2 Utilization - Volume 21, October 2017, Pages 292-301
نویسندگان
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