Enhanced oxygen vacancies to improve ethyl acetate oxidation over MnOx-CeO2 catalyst derived from MOF template

Abstract

Industrial volatile organic compounds (VOCs) are harmful to the environment and human health. Catalytic oxidation is the most effective method for end-of-pipe control. The challenges of VOC catalytic oxidation are the high space velocities and low oxidation temperatures. In this work, Mn cations were introduced into Ce-BTC supports by an impregnation method, after which the mixture was calcined. The as-synthesized CeO2-supported Mn catalyst MnOx-CeO2-s exhibited an outstanding activity for ethyl acetate (EtOAc) catalytic oxidation, which reached complete conversion at 210 °C (T99 = 210 °C), even at a high space velocity (WHSV = 60,000 mL g−1 h−1). With in situ UV Raman and other characterization methods, the Frankel oxygen vacancy (F-OV) was determined to be the crucial active site for EtOAc catalytic oxidation. The excellent low temperature activity of MnOx-CeO2-s benefited from the enhanced F-OVs concentration. The high temperature stability was attributed to the stable F-OVs recovery potential of the Ce-BTC-derived CeO2 support. The durability at a high space velocity was the result of the unique crossed channel structure inherited from Ce-BTC. These findings unraveled the crucial role of F-OVs in the EtOAc catalytic oxidation and the value of MOF-derived materials, which highlighted a feasible approach for the design of VOC-removal catalysts.