Effect of calcination process on performance of 3DOM CeMnO3 catalysts

Abstract

A series of 3DOM CeMnO3 perovskite catalysts were prepared by poly(methyl methacrylate) hard-templating-excessive impregnation method at calcination temperature of x °C (x = 600, 700, 800) and the heating rate of y °C/min (y = 1, 2, 5, 10). The samples were characterized by Brunauer-Emmett‐Teller method, scanning electron microscopy, transmission electron microscopy, H2‐temperature programmed reduction, X‐ray photoelectron spectroscopy, X‐ray diffraction, moreover, the effect of the calcination process on the catalytic activity of the samples were discussed by the catalytic combustion of toluene. The results show that the 3DOM CeMnO3 catalysts calcined at 600 °C promote the formation of a perovskite structure, inhibit the reduction of the Mn4+ species in the catalyst with high temperature. The catalyst expresses the complete macroporous structure, large specific surface area (38.8 m2/g), higher adsorption oxygen concentration and Mn4+ substance concentration, with a low T90%=172 °C. By preparing the catalysts at different calcination heating rates, it can be concluded that the catalyst possesses a high concentration of adsorbed oxygen and a low reduction temperature and a large specific surface area (40.42 m2/g) greatly promotes adsorption stage catalytic oxidation reaction and catalytic combustion of toluene at low temperature under the heating rate of 5 °C/min. When the heating rate is 1 °C/min, the catalyst has a complete macroporous structure (>250 nm), which is beneficial to the exchange of macromolecular substances during the catalytic reaction and the catalyst has a high concentration of lattice oxygen suitable for the catalysis of toluene in high temperature flue gas combustion.