High purity mullite used as a catalyst carrier

摘要

High purity mullite is produced by heating a single phase inorganic precursor gel to 1000 to 1400 deg C until complete formation of the mullite phase. The precursor gel is produced from an unstable aqueous silicic acid solution containing 0.6 to 18 wt.% SiO2, having a pH of 1.5 to 3.5 and containing condensed silicate ions and reactive silanol groups. After an ageing time of from 5 minutes to 3 days, it is reacted with an aqueous solution containing aluminium-oxo-hydroxo cations with an OH/Al ratio of 2.0 to 2.5 and a pH of 3 to 6.