Generation of abundant oxygen vacancies in Fe doped δ-MnO2 by a facile interfacial synthesis strategy for highly efficient catalysis of VOCs oxidation

A series of homogenous Fe-Mn oxides with superior catalytic oxidation activity was developed via interfacial redox-precipitation method for eliminating VOCs from industrial waste gas. Among them, Fe1Mn5 oxide achieved the optimum catalytic performance for toluene oxidation with a T90 of 209 ℃. In addition, the catalyst demonstrated superior stability for long-time operation and great water resistance. By combining an array of analytical techniques with DFT calculations, the results revealed that Fe doping and interfacial redox-precipitation method synergistically resulted in high concentration of oxygen vacancy defect over Fe1Mn5 oxide, which improved lattice oxygen mobility and oxygen species activity, thus enhancing its low temperature reducibility. Meanwhile, in situ DRIFTS analysis revealed that both the adsorbed oxygen species and lattice oxygen with improved mobility could interact with adsorbed toluene, thus facilitating rapid dehydrogenation of methyl and demethylation of toluene and promoting the breakage of CC bond in the aromatic ring.