Crystal plane engineering of CeO2 modulates interfacial electronic structure of V2O5/CeO2 catalysts for enhanced SO2 oxidation in alkylation waste acid valorization

Addressing the key issue of low SO 2 conversion efficiency in the treatment of waste acid from alkylation processes, this study employed a CeO 2 crystal plane engineering strategy to enhance the efficient conversion of SO 2 to SO 3 by modulating the interfacial structure of the V 2 O 5 /CeO 2 catalyst. Combining characterization techniques such as Raman spectroscopy, density functional theory calculations and diffuse reflectance infrared fourier transform spectroscopy, it was revealed that rod-shaped CeO 2 on the {110} crystal plane, due to enhanced interfacial electronic interaction induced by high concentrations of oxygen vacancies and optimal lattice oxygen mobility, promoted the formation of active monodentate sulphate intermediates at the molecular level whilst suppressing the deposition of inert species. The prepared V 2 O 5 /CeO 2 catalyst ({110} crystal plane) achieved an SO 3 yield of 779.5 μmol·g -1 ·h -1 at 350 °C, with a conversion rate of 88.2%, which was 1.51 times and 2.46 times higher than that of V 2 O 5 /CeO 2 ({100} crystal plane) and V 2 O 5 /CeO 2 ({111} crystal plane), respectively; moreover, the activity retention rate remained as high as 95.4% after a 12-hour stability test. This study provided clear structural design guidelines for high-performance SO 2 oxidation catalysts aimed at the high-value utilization of waste acids from alkylation processes.