On the role of the activation procedure of supported hydrotalcites for base catalyzed reactions: Glycerol to glycerol carbonate and self-condensation of acetone

Bulk and carbon nanofiber supported MgAl hydrotalcites have been investigated as solid base catalysts for the synthesis of glycerol carbonate and dicarbonate and for the self-condensation of acetone. The supported materials exhibited a 300 times higher activity compared to bulk activated hydrotalcites for the transesterification. The materials could be reused while maintaining a high yield of glycerol carbonate. The activity of the mixed oxide, i.e., hydrotalcite materials after high temperature activation was considerably higher than both gas-phase and liquid phase rehydrated samples for the glycerol reactions. In contrast in the acetone self-condensation reaction the rehydrated samples were more active. This indicates that the polarity of the catalyst related to the reactant properties has a huge impact on the performance of a solid base catalyst.