Ordered mesoporous MCo2O4 (M = Cu, Zn and Ni) spinel catalysts with high catalytic performance for methane combustion

Ordered mesoporous MCo2O4 (M=Cu, Zn and Ni) spinel catalysts were synthesized via nano-replication method using mesoporous silica KIT-6 as the hard template. They were applied to methane combustion, in comparison with bulk MCo2O4 spinel catalysts prepared by co-precipitation method. A combined N-2 adsorption-desorption, XRD and TEM results clearly confirm that mesoporous MCo2O4 (m-MCo2O4) spinel catalysts contain ordered mesostructure, resulting in the higher BET surface area and pore volume than bulk ones (b-MCo2O4). Moreover, the former catalysts demonstrate the better thermal stability as indicated by larger amount of MCo2O4 phase and smaller size of crystallite domain after calcination at 550 degrees C. Therefore, such excellent properties rationalize that the m-MCo2O4 spinel catalysts reveal higher catalytic activity for methane combustion than bulk counterparts. When it comes to the catalytic performance of the meso catalysts for methane combustion, the m-CuCo2O4 spinel catalyst has superior performance, which is related to the high normalized amount of Co3+ cations on the surface, as evidenced by XPS. (C) 2016 Elsevier B.V. All rights reserved.