Sulfonic-functionalized SBA-15 as an active catalyst for the gas-phase dehydration of glycerol

Sulfonic-functionalized mesoporous silicas (SBA-15) were used as catalysts in the gas-phase dehydration of glycerol at moderate temperature (275 and 300 ºC). For the tested conditions all the samples show a very high catalytic activity. At the lowest temperature and for 140 h on stream a nearly constant selectivity to acrolein of ca. 80 % could be obtained. Both the pore size and density of acid sites play an important role in the deactivation rate and selectivity: larger pore size may extend significantly the catalytic activity and high density of acid sites may reduce acrolein production. Increasing the temperature to 300 ºC is beneficial to the acrolein production, but it also leads to an increase of the deactivation rate