Visible light driven Z-scheme Fe2O3/SmFeO3/palygorskite nanostructure for photo-SCR of NOx

Commercial V–Ti oxide catalysts are widely used in the selective catalytic reduction (SCR) of NOx, however it requires high reaction temperature and poisonous V components. In addition, the deactivation induced by the SO2 and H2O in the flow gases has restricted its extensive applications. To address those problems, a series of Fe2O3/SmFeO3/palygorskite (Pal) with various Fe/Sm molar ratios (nFe/nSm) were prepared by a sol–gel method for photocatalytic assisted SCR of NOx at low temperature. The morphology and structural properties of as-prepared catalysts were characterized by various measurements. Results indicated that the rational addition of Fe species could not only formed Z-scheme heterostructure Fe2O3/SmFeO3 with high redox property, but also effectively restrained the generation of sulfate species. The catalysts achieved the highest 95% conversion rate and 100% N2 selectivity when the nFe/nSm = 2 with remarkable SO2 and H2O resistance.