Preparation, characterization, and catalytic performance of high efficient CeO2-MnOx-Al2O3 catalysts for NO elimination

A series of CeO2-MnOx-Al2O3 mixed oxide catalysts (Ce:Mn:Al mole ratio = 6:4:x, x = 0.25, 0.5, 1, 2) were prepared by a simple one-step inverse co-precipitation method to investigate the influence of the incorporation of Al3+ into CeO2-MnOx mixed oxides. CeO2-MnOx CeO2-Al2O3, and MnOxAl2O3 mixed oxides, and CeO2 were prepared by the same method for comparison. The samples were characterized by XRD, Raman, N-2 physisorption, H-2-TPR, XPS, and in situ DRIFTS. The catalytic re duction of NO by CO was chosen as a model reaction to evaluate the catalytic performance. The incorporation of a small amount of Al3+ into CeO2-Mna, mixed oxides resulted in a decrease of crystallite size, with the increase of the BET specific surface area and pore volume, as well as the in crease of Ce3+ and Mn4+. The former benefits good contact between catalyst and reactants, and the latter promotes the adsorption of CO and the desorption, conversion and dissociation of adsorbed NO. All these enhanced the catalytic performance for the NO+CO model reaction. A reaction mechanism was proposed to explain the excellent catalytic performance of CeO2-MnOx-Al2O3 catalysts for NO reduction by CO. (C) 2016, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.