Enhanced Low-Temperature Activity of CO2 Methanation Over Ni/CeO2 Catalyst

• Published in: Catalysis letters 2022-03, Vol.152 (3), p.872-882
• Main Authors: Ma, Yuan, Liu, Jiao, Chu, Mo, Yue, Junrong, Cui, Yanbin, Xu, Guangwen
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalysis; Catalysts; Catalytic activity; Catalytic converters; Cerium oxides; Chemical precipitation; Chemical properties; Chemistry; Chemistry and Materials Science; Crystallites; Dispersion; Industrial Chemistry/Chemical Engineering; Low temperature; Methanation; Nanorods; Organometallic Chemistry; Oxygen; Physical Chemistry; Surface area; Vacancies
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-021-03677-7

CeO 2 nanorods (CeO 2 -nrs), CeO 2 nanocubes (CeO 2 -ncs) and CeO 2 nanopolyhedrons (CeO 2 -nps) were prepared by hydrothermal method and then NiO crystallites were deposited on these supports by precipitation-deposition, respectively. The physic-chemical properties of Ni/CeO 2 catalysts were characterized and performances for carbon dioxide methanation reaction were tested. The Ni/CeO 2 -nrs sample shows well metal dispersion and high concentration of oxygen vacancy, which leads to the high catalytic activity for CO 2 methanation. Especially at 300 °C, the CO 2 conversion could reach 60%. Further analysis reveals that the content of oxygen vacancy has a positive correlation with the surface area of catalyst. The largest surface area results in the most of oxygen vacancy on the Ni/CeO 2 -nrs catalyst, and then a large amount of CO 2 could be activated at low temperatures. Meanwhile, large surface area facilitates the dispersion of active metals, and improves the degree of H 2 activation. The combined effect results in the promotion of catalytic activity for CO 2 methanation at low temperatures. Graphic Abstract CeO 2 nanorods (CeO 2 -nrs), CeO 2 nanocubes (CeO 2 -ncs) and CeO 2 nanopolyhedrons (CeO 2 -nps) supported Ni catalysts were prepared. These catalysts ware tested for CO 2 methanation and further characterized by BET, XPS, TEM, H 2 -TPR and TPD. The results showed that the content of oxygen vacancy has positive correlation with the specific surface area of catalyst.