Enhanced sulfur resistance by constructing MnOx-Co3O4 interface on Ni foam in the removal of benzene

The catalytic degradation of volatile organic compounds (VOCs) in the presence of SO2 remains an urgent issue for industrial applications. Herein, we constructed an MnOx-Co3O4 interface on Ni foam (MnxCoy-NF catalysts) to improve SO2 resistance for benzene degradation. The surface decoration of MnOx on MnxCoy-NF catalysts could generate a Co-Mn interface to tune the redox ability and active oxygen species. The Mn1Co1-NF catalyst showed high Co3+/Co2+ and Mn3+/Mn4+ ratios as well as a high O-latt/O-ads ratio, which are conducive to excellent low-temperature reducibility. Benefiting from abundant interfacial active sites, the Mn1Co1-NF catalyst exhibited superior catalytic activity with T-50 and T-90 values of 259 and 290 degrees C and SO2-tolerance for benzene degradation. Results of in situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculation revealed that surface metal sulfate species were preferentially formed on surface Mn sites rather than Co sites, thereby retarding the poisoning of Co-Mn interfacial active sites. Correspondingly, the ring-opening of benzoquinone into maleate species on the Mn1Co1-NF catalyst was only slightly inhibited by the introduction of SO2. This work provides a novel route to design SO2-resistant catalysts for VOC degradation in practical applications.