Catalytic combustion of lean methane over MnCo2O4/SiC catalysts: Enhanced activity and sulfur resistance. (1st September 2022)

• Record Type: Journal Article
• Authors: Zhao, Yannan; Gu, Zhenhua; Li, Danyang; Yuan, Jiangyong; Jiang, Lei; Xu, Haiwen; Lu, Chunqiang; Deng, Guixian; Li, Ming; Xiao, Wei; Li, Kongzhai
• Is Part Of: Fuel. Volume 323(2022)
• Publication Date: 2022-09-01
• Subjects: Methane combustion -- xMCO/SiC catalyst -- Sulfur resistance -- Surface adsorbed oxygen -- Co3+ species; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.124399
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: In this study, we developed a novel catalyst for methane combustion by dispersing MnCo2 O4 nanoparticles on a SiC substrate. The strong interaction between SiC and MnCo2 O4 results in more active species on the catalyst surface, which significantly improves the catalyst activity. 60%MnCo2 O4 /SiC sample shows a significant reduction in both the ignition temperature and the T90 . 60%MnCo2 O4 /SiC sample also effectively suppresses the formation of a large amount of sulfate on the catalyst surface in the high sulfur atmosphere, showing superior sulfur resistance. Highlights: MnCo2 O4 /SiC shows excellent catalytic activity for methane combustion. Excellent catalytic activity is due to the abundant Oads and surface Co 3+ species. The presence of SiC accelerates the formation of carbonate and formate species. MnCo2 O4 /SiC shows good sulfur resistance and stability in high sulfur atmosphere. The presence of SiC inhibits the formation of sulfate on the catalyst surface. Abstract: The simultaneous control of catalytic activity and sulfur resistance is a challenging task for non-noble metal catalysts in the domain of heterogenous catalysis. Herein, by dispersing MnCo2 O4 (MCO) nanoparticles on a SiC substrate, we develop a novel catalyst for methane combustion that exhibits excellent low-temperature catalytic activity as well as high sulfur resistance. Strong interactions between SiC and MCO reduce the crystallite size of MCO and increase the specific surface area of the catalyst and the concentration of the active species, namely, Co 3+ and surface oxygen species. The 60%MCO/SiC sample shows the highest catalytic activity, with T10, T50, and T90 values of 335, 375, and 444 °C, respectively, at a space velocity of 45, 000 mL∙g −1 ∙h −1 . In-situ diffuse reflectance infrared spectroscopy experiments and physicochemical characterizations indicate that the enhancement of catalytic activity is mainly attributed to the abundant adsorbed oxygen and surface Co 3+ species in the catalysts that accelerate the formation of carbonate and formic acid species during methane conversion. The 60%MCO/SiC sample also exhibits high sulfur resistance, which is mainly attributed to the inhibiting effect of SiC on the catalyst for bulk sulfate formation. The findings of this study provide insights for the fabrication of catalysts with high activity as well as high sulfur resistance.