Cerium Containing Siliceous MCM-22: Preparation, Characterization and Its Potential Application towards Oxidation of Isoeugenol to Vanillin

Abstract

The main objective is to prepare cerium containing aluminium-free siliceous MCM-22 (AF-CeMCM-22) catalyst by in-situ hydrothermal method, its characterization, and catalytic application for the conversion of biomass model components. Powder XRD, FTIR, and BET surface area were used to study the microstructure of the samples. The powder XRD patterns showed a distinguished MCM-22 framework structure with a uniform dispersion of cerium ions in the MCM-22 framework. SEM images of the cerium AF-CeMCM-22 showed a spherical morphology formed out of platelet flakes which have a surface area in the range of 173-145 m2g1. 29Si NMR and DR-UV-Vis studies confirmed the well-condensed nature of the silica framework in MCM-22 and the presence of cerium ions as Ce(IV) in the extra framework environment. The resultant AF-CeMCM-22 was found to be a promising catalyst for the conversion of isoeugenol to vanillin at 60 ℃ in presence of H2O2 (oxidant) with a selectivity of 71%. Further, the activity is retained for several cycles. Zeolites and zeolite like microporous materials are well known as potential heterogeneous acid catalysts, whose discovery has made a significant impact in the petroleum, petrochemical and fine chemical industries. ]. In recent years, zeolite, zeolites like molecular sieves, and inorganic oxide-based heterogeneous catalysts played a significant role in biomass valorization to receive value-added chemicals. Thus we focused on utilization of zeolite for biomass transformation. Preparation of Cerium containing aluminium-free siliceous MCM-22 (AF-CeMCM-22) by the in-situ hydrothermal method and explore its importance on biomass transformation. Powder XRD, FTIR and BET surface area were used to study the microstructure of the samples. SEM and FE-SEM were used to study morphology, TGA was used to evaluate the thermal stability, and 29Si NMR and DR-UV-Vis were used to study the environment of the MCM-22 framework. The prepared and confirmed material was used for the oxidation of levulinic acid over the liquid phase setup. Gas chromatography was used to evaluate the catalytic study, such as conversion and selectivity; also, GCMS was used for the confirmation of products.