Superacid ZrO2/SO42- (SZ) was supported on mesoporous alumina (MA) to synthesize a novel superacid catalyst (SZMAP) with high active surface area. The synthesized catalyst was characterized by both physical and chemical methods, including XRD, BET, NH3-TPD and TEM. The prepared superacidic mesoporous alumina (SZMAP) showed typical gamma-alumina phase patterns and uniform mesoporous structures with a regular channel arrangement. NH3-TPD analysis indicated that SZMAP has superacidic characteristics. The SZMAP catalyst was used in the dehydration of glycerol to acrolein. Results showed that SZMAP showed much higher catalytic activity than the bulk superacid, ZrO2/SO42-. (SZ), and MA due to the high dispersion of active SZ molecules, which results from a large surface area and uniform mesopores of mesoporous alumina.