Mesoporous materials as catalysts for the production of chemicals: Synthesis of alkyl glucosides on MCM-41

The synthesis of alkylglucosides from glucose and n-butanol has been carried out successfully on Al-MCM-41 mesoporous materials. The influence of the chemical composition (Si/Al) and pore dimensions on activity and selectivity has been studied. It has been found that a higher concentration of acid sites does not guarantee a better catalytic performance, and the adsorption-desorption properties of the material play a determinant role in this reaction where the two reactants and the product have very different polarities. On the other hand, in the range of pore sizes studied here, the larger the diameter of the pore at the same level of Al contents, the more active is the final catalyst. The catalyst loses activity during the process due to the presence of strongly adsorbed molecules. Soxhlet extraction by methanol followed by water does not recover all the initial activity but produces a loss of crystallinity. However, the catalyst could be fully regenerated by calcination in air at 773 K. (C) 1999 Academic Press.