Efficient low-temperature catalytic combustion of trichloroethylene over flower-like mesoporous Mn-doped CeO2 microspheres

Flower-like mesoporous Mn-doped CeO2 microspheres with three-dimensional (3D) hierarchical structures were successfully prepared by a hydrothermal method with the aid of glucose and acrylic acid and subsequent particular thermal treatment, and characterized by SEM, XRD, N-2 adsorption/desorption, H-2-TPR, XPS, Raman spectra and so on. The results show that the atomic ratios of Mn/(Ce + Mn) in the Ce-Mn-O samples as well as their morphologies affect obviously their catalytic performances for low-temperature catalytic combustion of trichloroethylene (TCE). These flower-like Ce-Mn-O microspheres have not only very excellent activity but also high stability, compared with pure flower-like CeO2 microspheres or bulk Ce-Mn-O samples. The flower-like sample with atomic ratio of Mn/(Ce + Mn) of 0.21 exhibits the best activity, for instance, T-50 (the temperature for 50% conversion of ICE) is as low as 87 degrees C, showing much higher catalytic activity than the sample prepared by a co-precipitation or sol-gel method. High surface area, high oxygen mobility and rich surface active oxygen species are responsible for the high catalytic performance of flower-like Mn-doped CeO2 microspheres, compared with general Ce-Mn-O mixed oxides. (C) 2010 Elsevier B.V. All rights reserved.