PREPARATION OF NANOFIBROUS γ-Al_2O_3 PARTICLES WITH LARGE PORE VOLUME FROM H_2O_2 AND SODIUM ALUMINATE SOLUTIONS

Nanofibrous γ-Al 2O 3 with very large pore volume was successfully prepared by precipitation from H 2O 2 and sodium aluminate solutions combined with dispersing and washing the precipitate with ethanol.The effects of ethanol washing and water washing on structure, morphology and texture properties of pseudoboehmite-calcined γ-Al 2O 3 were comparatively studied with XRD, FT-IR,TG-DSC,TEM,BET and mercury porosimeter.The ethanol-processed γ-Al 2O 3 presented fibrous-like texture about 10 nm thick and over 100 nm long whose pore volume and BET surface area could reach about 2.23 ml·g -1 and 222.0 m2·g -1, respectively.However,the secondary particles of the water-processed γ-Al 2O 3 had no regular shape and its as-mentioned texture properties of pore volume and BET surface were only 0.37 ml·g -1 and 162.3 m2·g -1,respectively. CH 3CH 2O—groups on the surface of ethanol-processed pseudoboehmite particles could not only induce fiber formation through hydrogen bonding between the oxide groups and the surface OH—groups, but also inhibit chemical Al—O—Al bonds formation among the adjacent particles and thus hard agglomerate could be prevented.