Ceramic monolith supported Mn-Ce-M ternary mixed-oxide (M=Cu, Ni or Co) catalyst for VOCs catalytic oxidation

The MOx (M=Cu, Ni or Co) modified manganese-cerium mixed-oxide catalysts supported on ceramic monolith were prepared by sol-gel method and examined for the catalytic combustion of o-xylene. Results show that the addition of CuOx could significantly enhance the catalytic properties of the monolithic catalysts, which may be correlated with the Mn-Cu synergistic interaction. The effects of the preparation parameters including the Cu content, the total amount of active phase and the calcination temperature and time, as well as the reaction conditions, i.e., the space velocity and concentration of o-xylene, on the catalytic performance for the combustion of o-xylene were also investigated. It is shown that the MnCeCu0.4/monolith catalyst with the active phase loading of 11.4 wt% and calcined at 500 °C for 3 h displays the highest catalytic activity. When the concentration of o-xylene is 1000 ppm and the space velocity is 10,000 h−1, the temperature at which 90% o-xylene conversion is reached is 277 °C. It is also seen that the optimum catalyst has a good catalytic stability and exhibits an excellent activity not only at a rather high space velocity but also within a wide range of o-xylene concentration. Furthermore, the optimum catalyst also show the high combustion performance for other hydrocarbons, e.g., n-butanol and styrene.