The production of vanillin from lignin-derived vanillyl alcohol poses a great deal of research interest because of the availability of renewable lignin in abundant quantities. In the present study, a series of copper-doped ceria (CeO₂) catalysts were prepared by a modified template-assisted method, characterized by various techniques, and explored for the oxidation of vanillyl alcohol to vanillin with molecular oxygen as the oxidant at normal atmospheric pressure. Interestingly, a 10% Cu-doped ceria (Cu_0.1Ce_0.9O_2−δ) catalyst exhibited superior catalytic activity for the oxidation of vanillyl alcohol with 95% and 100% conversions at atmospheric and moderate pressures, respectively, with 100% vanillin selectivity in both cases. A thorough characterization (XRD, BET surface area, Raman spectroscopy, SEM, TEM, XPS, and H₂-TPR) of the synthesized mesoporous oxides (CuO, CeO₂, Cu_0.05Ce_0.95O_2−δ, Cu_0.1Ce_0.9O_2−δ, and Cu_0.15Ce_0.85O_2−δ) revealed that mixed oxide catalysts exhibit more oxygen vacancies and better redox behavior in comparison to the single oxides, which lead to improved catalytic activity and selectivity. Reaction parameters, such as reaction temperature, reaction time, catalyst amount, and the solvent, were also optimized for the reaction.

The Ce_0.7Bi_0.3O₂ catalyst exhibited superior catalytic activity in comparison to other cerium and bismuth based mixed oxides for styrene oxidation with 95% conversion and 85% selectivity to styrene epoxide.

A series of mesoporous ceria-supported vanadium oxide catalysts were prepared and explored for aerobic oxidation of ethylbenzene to acetophenone without the involvement of any solvent or additive. Catalysts with varying contents of V₂O₅ (3, 6, and 10 wt%) on a mesoporous CeO₂ support were prepared by the wet-impregnation method. Catalysts were characterized using techniques namely, XRD, Raman spectroscopy, BET surface area analysis, ICP-OES, FE-SEM, HR-TEM, XPS, and H₂-TPR to establish a correlation between the physicochemical properties and catalytic performance. Among the investigated catalysts, the catalyst with 6 wt% of V₂O₅ on mesoporous ceria showed better activity with 69% ethylbenzene conversion and 88% acetophenone selectivity. The superior activity of this catalyst was ascribed to a strong synergetic interaction between ceria and vanadia as well as the formation of a CeVO₄ phase, and a high specific surface area. The reaction parameters like temperature, pressure, and the amount of catalyst were optimized for possible commercial utilization. The stability of the catalyst was also investigated by the reusability test and was found to be stable and active up to five cycles.