Enhancement effect of Mn doping on Co3O4 derived from Co-MOF for toluene catalytic oxidation

Abstract

The design of Co-Mn composite oxides catalysts derived from MOF is significant for catalytic combustion of toluene. Here, a series of M-CoaMnbOx, with enhanced catalytic properties compared with that of M-Co3O4, were successfully prepared through pyrolysis of Mn-doped Co-MOF. The as-synthesized M-Co1Mn1Ox (Co:Mn = 1:1) exhibits an optimal catalytic activity with 90% toluene conversion reached at 227 °C, which benefits from the increase of Co3+, Oads and the synergistic effect between Mn and Co. According to the analysis of the in situ diffuse reflectance infrared Fourier transform spectroscopy, toluene could be degraded easier on M-Co1Mn1Ox with lower activation energy than M-Co3O4. The main intermediate products are benzaldehyde, benzoic acid, anhydride, and maleate species. Those findings reveal the value of Mn doping for improved activity of toluene oxidation on MOF derived Co3O4, which provide a feasible method for the construction of toluene-oxidation catalysts.