Esterification processes based on functionalized mesoporous solids

• Structure of SBA-15 or MCF has an impact on MPTMS anchoring.
• Nature of transition metal (Nb or Mn) does not influence the MPTMS anchoring.
• Metal incorporation into mesoporous structure enhances MPTMS oxidation.
• Nb containing samples are more active in esterification than Nafion SAC 13.
• 2-Proplyl formation linearly depends on the number of acidic sites.

The abilities of niobium and manganese to enhance oxidation of thiol groups in (3-mercaptopropyl)trimethoxysilane (MPTMS) used for functionalization of SBA-15 and MCF materials, by hydrogen peroxide in order to form catalysts with acidic properties were evaluated. Materials obtained were characterized by: N2 adsorption, XRD, XRF, elemental and thermal analyses and titration of acid sites. The highest concentration of acidic sites was found for SBA-15 structure modified with niobium. The catalytic activities of materials obtained were examined in esterification of acetic acid with ethanol and 2-propanol. Both niobium containing samples (MP-NbSBA-15 and MP-NbMCF) showed high yields of ethyl and 2-propyl acetate. The amount of 2-propyl acetate formed was found to linearly depend on the number of acid sites on the catalyst surface. The reuse tests proved that the drop in the catalyst activity in consecutive catalytic cycles is not too high, which suggests possible application of the materials obtained after further optimization.

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