Crystal plane engineering of CeO₂ modulates interfacial electronic structure of V₂O₅/CeO₂ catalysts for enhanced SO₂...

Addressing the key issue of low SO₂ conversion efficiency in the treatment of waste acid from alkylation processes, this study employed a CeO₂ crystal plane engineering strategy to enhance the efficient conversion of SO₂ to SO₃ by modulating the interfacial structure of the V₂O₅/CeO₂ 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 CeO₂ 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 V₂O₅/CeO₂ catalyst ({110} crystal plane) achieved an SO₃ 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 V₂O₅/CeO₂ ({100} crystal plane) and V₂O₅/CeO₂ ({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 SO₂ oxidation catalysts aimed at the high-value utilization of waste acids from alkylation processes.