Solid acid catalysts for dehydration of glycerol to acrolein in gas phase

The reaction of glycerol dehydration to acrolein was performed at temperatures 220-300 A degrees C over Keggin-type heteropolyacid (H(3)PW(12)O(40)center dot xH(2)O), supported on alumina and W-modified SBA-15 (Si/W = 20). The supports and catalysts were characterized by nitrogen adsorption, XRD, IR, UV-Vis DRS, SEM, and TPD of NH(3). The acid sites strength, determined according to data from TPD of ammonia, follows the order: HPW/W-SBA-15 > W-SBA-15 > H(3)PW(12)O(40) > HPW/gamma-Al(2)O(3) > gamma-Al(2)O(3). It was found that this order well correlates with the catalytic activity of studied samples. The most active and selective sample, HPW/W-SBA-15, showed acrolein selectivity of about 75% at almost 100% conversion of glycerol in all studied temperature interval.