Catalytic oxidation of volatile organic compound over cerium modified cobalt-based mixed oxide catalysts synthesized by electrodeposition method

• Published in: Applied catalysis. B, Environmental Vol. 271; p. 118941
• Main Authors: Wang, Jing, Yoshida, Akihiro, Wang, Peifen, Yu, Tao, Wang, Zhongde, Hao, Xiaogang, Abudula, Abuliti, Guan, Guoqing
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.08.2020; Elsevier BV
• Subjects: Carbon dioxide; Catalysts; Catalytic converters; Catalytic oxidation; Cerium; Chemical synthesis; Co-based mixed oxide catalyst; Cobalt; Cobalt compounds; Electrodeposition; Electrodeposition method; Lattice vacancies; Low temperature; Metal foams; Nanostructure; Nickel; Organic compounds; Oxidation; Oxygen; Physicochemical properties; Physiochemistry; Porous nanosheet structure; Redox properties; Selectivity; Synergistic effect; Toluene; Transition metals; VOCs; Volatile organic compound; Volatile organic compounds; Water vapor; X ray photoelectron spectroscopy; Electrodeposition method; Catalytic oxidation; Volatile organic compound; Co-based mixed oxide catalyst; Porous nanosheet structure
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.118941

[Display omitted] •Electrodeposition was used to prepare Co-Ce based catalyst for the first time.•Mixed metal species with porous nanosheet structure were uniformly deposited.•Cerium doping improved the active species and reducibility of Co-Ce based catalyst.•The optimum catalyst was highly stable and active even in the presence of steam. Cerium (Ce) modified cobalt (Co)-based (Co-Ce) mixed oxide catalysts were electrodeposited on nickel foam (NF) with different Co/Ce molar ratios and directly used for the catalytic oxidation of toluene. Physicochemical properties of the obtained Co-Ce/NF catalysts were obtained by SEM, XRD, TEM, H2-TPR, O2-TPD and XPS techniques. It was found that the Co-Ce mixed oxide with a well nanosheet structure could be uniformly deposited on NF by adjusting the Co/Ce molar ratio in the initial solution for electrodeposition. H2-TPR analysis indicated that Ce doping improved the reducibility of Co-Ce/NF catalyst due to the synergistic effect between Co and Ce. In the toluene catalytic oxidation, the 10Co-Ce/NF catalyst prepared with a molar ratio of Co/Ce at 10 in the initial solution achieved the best catalytic performance among all the catalysts with a complete toluene conversion temperature of 268 °C and CO2 selectivity of 100 %. This can be contributed to the superior physiochemical properties of uniform nanosheet structure, rich surface and lattice active oxygen species at low temperatures, high content of Co3+ active species with high oxygen vacancies and Ce4+/Ce3+ redox couples in the catalyst. In addition, the 10Co-Ce/NF catalyst exhibited long-term stability in the presence of water vapor. It is expected that such a time-saving electrodeposition method could provide a promising way to prepare highly active and stable transition metal based catalysts for the oxidation of VOCs.