Fabrication of Hierarchical Co/MgO Catalyst for Enhanced CO2 Reforming of CH4 in a Fluidized-Bed Reactor

This work reports facile fabrication of fluidizable hierarchical Co-MgO particles with high dispersion of Co nanoparticles (NPs) and high surface oxygen vacancies for matching with the fluidized-bed reactor. The hierarchical Co-MgO catalyst exhibits higher activity and thermal stability for CH4-CO2 reforming than the conventional impregnation Co/MgO catalyst. The enhanced prevention of Co NPs sintering of the hierarchical Co-MgO catalyst is attributed to the multilayer structure and the exposed MgO (111) face, which creates high surface oxygen vacancies, induces high Co dispersion to restrain Co NPs sintering, and supplies high resistance to graphite carbon deposition. A formation mechanism for the hierarchical MgO structure is also proposed. This formation of incomplete rhombohedron MgO particles with an exposed octahedral MgO (111) face is attributed to the electrostatic interaction of OH-. The proposed approach to improving catalytic activity by creation of hierarchical MgO particles can be expanded to other metal oxide catalysts. (c) 2018 American Institute of Chemical Engineers AIChE J, 65: 120-131, 2019