Investigation of the catalytic properties in the dehydration of 1-phenylethanol in styrene process of an amorphous aluminum hydroxyl gel after its heat treatments

摘要

Styrene is the widely used as a monomer, which is produced by PO-technology using γ-alumina catalyst. It is mainly synthesized by the precipitation of aluminum nitrate solution by ammonia. However, amorphous aluminum compounds are formed after synthesis with pseudoboehmite, which is a precursor of the alumina. Therefore, the product of precipitation and the alumina derived by its heat treatment at the 550 and 750°C were synthesized and investigated. Starting product consists ～86 wt.% of amorphous aluminum compounds and 14 wt.% of pseudoboehmite. These substances transform into amorphous alumina from and γ-Al_2O_3 (1) after calcination at 550°C and show low catalytic characteristics in vapor-phase of 1-phenylethanol into styrene. However, after heat treatment at 750°C, when amorphous alumina transform in γ-Al_2O_3 (2), the conversion, selectivity and styrene yield increase by 10-20%.