Ceria-doped UiO-66-derived carbon–zirconia supported vanadium catalysts for CO2-ODHP: Synergistic effects of MSI tuning, oxygen vacancies, and spillover behavior

Abstract

In this study, a series of zirconia-supported vanadium oxide catalysts—VZ (V₂O₅@ZrO₂), VZC (V₂O₅@ZrO₂/C, UiO-66-derived), and Ce-VZC (Ce-doped-V₂O₅@ZrO₂/C)—were synthesized and systematically evaluated for the CO₂-assisted oxidative dehydrogenation of propane (ODHP). The incorporation of a carbonaceous framework derived from UiO-66 and the strategic doping of ceria were employed to optimize metal-support interactions (MSI), enhance oxygen vacancy formation, and promote the spillover of key intermediates. A comprehensive characterization strategy—including XRD, FT-IR, HR-XPS, FE-SEM/EDS, BET, H₂-TPR, and H₂/CO₂-TPD—combined with DFT calculations was undertaken to correlate structure–property–performance relationships. The results reveal that Ce-VZC exhibited the highest surface basicity, active site dispersion, reducibility, and oxygen vacancy concentration, all of which translated into superior catalytic performance and stability. DFT calculations confirmed the lowered energy barriers for propane dehydrogenation and CO₂ activation in Ce-VZC, while also demonstrating moderated MSI and longer spillover distances of H, O, and CO₂ species. Among the catalysts, Ce-VZC achieved the highest propane conversion (19.3 %) and propylene yield (13.9 %) with excellent stability over 600 min of time-on-stream. This work highlights the synergistic effect of ceria doping and carbon integration in tuning MSI, redox properties, and intermediate spillover, offering a promising route toward the rational design of high-performance ODHP catalysts.