High porosity alumina with high surface area and low density - made by hydrolysis in presence of substances giving ammonia and/or carbon dioxide

摘要

Prepn. of high-porosity alumina with high surface area and low bulk density by hydrolysis of Al alcoholates at 40-90 degrees C in aq. soln. contg. 8-20 wt.% substance (I) which gives off NH3 and/or CO2 or drying or activating. Amt. of (I) is 0.5-3 pts. per 10 pts. Al alcoholates. Cpd. (I) is pref. (NH4)2CO3, ure, urotropin, ammonium acetate or esp. NH4HCO3. Prod. is used as catalysts and carriers in chemical processes, esp. in the oil industry. Alumina with surface area 300-400 m2./g. bulk density 0.13-0.3 g/ml. and pore vol. 1.1-2.1 ml./g. with =50% of pores with dia. 1000 A, is obtd. by a simple process at low temps., without requiring azeotropic distn. of the water present.