Enhanced Catalytic Activities of MnOx/Co3O4 Nanocomposites Prepared via MOFs-Templated Approach for Chlorobenzene Oxidation

Abstract Chlorinated volatile organic compounds (CVOCs) existing widely in the industries are harmful to the environment and human’s health. It is urgent to develop highly efficient catalysts for their combustion. Herein, a series of porous MnOx/Co3O4 nanocomposites are synthesized by the pyrolysis of Mn@Co-ZIF-67 precursors, in which the Mn ions are introduced by impregnation method. XRD, Raman, ICP-OES, BET, SEM, TEM, XPS, O2-TPD, and H2-TPR have been performed to investigate the as-prepared catalysts’ physicochemical properties. The optimal catalyst MnOx/Co3O4-4h exhibits 90% and 100% chlorobenzene (CB) conversion (1000 ppm, Air, WHSV = 60,000 mL/(g h)) at 334 oC and 350 oC, respectively. And the better catalytic performance over MnOx/Co3O4-4h compared with the pure Co3O4 and other MnOx/Co3O4 nanocomposites mainly ascribes to its porous structures, homogeneous dispersion, optimal Mn/Co molar ratio, more lattice defects, and higher surface OLatt/OAds ratio. Meanwhile, MnOx/Co3O4-4h displays high stability and resistance to moisture. Main intermediates have been further investigated by in situ DRIFT, and the degradation mechanism has been proposed according to the analysis of intermediates.