Keywords and Phrases
Bifunctional catalysts; Catalytic performance; CO2 utilization; Deactivation; Dimethyl ether; Heterogeneous catalysis
Direct synthesis of dimethyl ether (DME) via CO2 hydrogenation has received great attention, owing to the global warming caused by CO2 emission and increasing energy demand worldwide. In this works, three major aspects of bifunctional catalysts development were studied: (1) investigation of the roles of interaction in the CuO-ZnO-ZrO2-Al2O3/HZSM-5 bifunctional catalysts, (2) deactivation and regeneration of CuO-ZnO-ZrO2-Al2O3 with different zeolitic catalysts for one-step CO2 hydrogenation to dimethyl ether, and (3) study on the enhancement of activity and stability of CZZA/HZSM-5 bifunctional catalysts via the introduction of promoters using different synthesis methods (i.e., Fe via co-precipitation, Pd via impregnation, and ZrO2 via atomic layer deposition).
The interaction between CZZA and HZSM-5 played an important role in maintaining good activity and stability of the bifunctional catalysts. A low-temperature regeneration (250 °C) under the air atmosphere is a more effective method than higher temperature (> 300 °C) for the recovery of catalytic activity of deactivated CZZA/HZSM-5 bifunctional catalysts. Introduction of Fe into CZZA via co-precipitation method could greatly improve the stability of the catalyst. Zirconium oxide (ZrO2) on CuO-ZnO-Al2O3 (CZA) catalysts by atomic layer deposition (ALD) was proved to enhance the catalytic performance of CZA/HZSM-5 bifunctional catalysts for dimethyl ether synthesis. The modification of Pd on aged CZA precursor composed of a mixture of zincian-malachite and hydrotalcite-like phases, showed higher methanol yield under mild reaction conditions than CZA catalyst, benefited from hydrogen spillover effect”--Abstract, page iv.
Ludlow, Douglas K.
Okoronkwo, Monday Uchenna
Chemical and Biochemical Engineering
Ph. D. in Chemical Engineering
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Roles of interaction between components in CZZA/HZSM-5 catalyst for dimethyl ether synthesis via CO₂ hydrogenation
- Deactivation and regeneration of CuO-ZnO-ZrO₂-Al₂O₃ with different zeolitic catalysts for one-step CO₂ hydrogenation to dimethyl ether
- Enhanced stability of Fe-modified CuO-ZnO-ZrO₂-Al₂O₃/HZSM-5 bifunctional catalysts for dimethyl ether synthesis from CO₂ hydrogenation
- Ultra-thin ZrO₂ overcoating on CuO-ZnO-Al₂O₃ catalyst by atomic layer deposition for improved catalytic performance of CO₂ hydrogenation to dimethyl ether
- Pd-modified CuO-ZnO-Al₂O₃ catalysts via mixed-phases-containing precursor for methanol synthesis from CO₂ hydrogenation under mild conditions
xvii, 214 pages
© 2021 Xiao Fan, All rights reserved.
Dissertation - Open Access
Fan, Xiao, "Catalytic carbon dioxide hydrogenation to methanol/dimethyl ether over copper-based catalysts" (2021). Doctoral Dissertations. 3055.