Mesoporous MnCoOx Catalysts Coupled with Non-thermal Plasma for Highly Efficient Ethyl Acetate Decomposition

Non-thermal plasmas coupled with heterogeneous catalysts are known to achieve highly efficient removal of volatile organic compounds. However, the selection of an appropriate catalyst and operating parameters remains challenging. In this study, research is conducted on transition metal MnCoOx mesoporous materials as catalysts for the decomposition of ethyl acetate (EA) in a post plasma-catalytic system. Mesoporous MnCoOx bimetallic oxides with different molar ratios are synthesized using KIT-6 mesoporous silica as a hard template. The prepared composite materials are characterized by different characterization techniques. All the new composites retain the ordered mesoporous structure of the original KIT-6 template. The molar ratio of Mn/Co can alter the physicochemical properties of a catalyst, consequently impacting its catalytic activity. The meso-Mn3Co1Ox catalyst exhibits the highest catalytic activity in the plasma-catalysis system for removal of ethyl acetate, which can be attributed to the interactions between Mn and Co, such as crystal structure, redox properties, and redox pairs of Mn4+/Mn3+ and Co2+/Co3+. These factors contribute to the observed differences in catalytic performance. Through DFT studies on the adsorption of EA on metal oxide catalyst surfaces, it was discovered that doping Co on MnO2 surface and the presence of specific oxygen vacancies significantly enhances the adsorption of EA. On Co-doped MnO2 surfaces, the adsorption energy is significantly improved when EA molecules bond with Mn atoms. The effects of different operation parameters on the removal efficiency of EA are also systematically studied.