Synthesis of porous γ-alumina with resorcinol-formaldehyde gel template via spray drying

Abstract

The synthesis of porous alumina powder by aluminium preformed sol and the controlling textural properties of alumina by using synthesized carbon template via spray drying process have been studied. Firstly, aluminium acetylacetonate (A) has been dissolved with formaldehyde solution (F) to form aluminium preformed sol. Resorcinol-formaldehyde solution has been also prepared by sol-gel processing as assisted-template to obtain high porosity alumina. The conditions to prepare the preformed aluminium sol and RF-gel were studied in the different aging time. In addition, the sol-gel reaction was studied with the different aluminium acetylacetonate to formaldehyde (A/F) molar ratio and resorcinol (A/R) molar ratio. The preformed aluminium sol was added into RF solution and use ethanol as solvent of the mixed gel. To obtain the powder of aluminium/RF-gel composite, the mixed gel was dried via spray dryer. The powder was further calcined to obtain porous γ-alumina at 800°C. The results show the maximum surface area of conventional dried alumina is 327 m²/g while the maximum surface area of spray dried alumina is 209 m²/g. Although the alumina particle from spray dryer is lower surface area than the particle from conventional drying, the spray dried products has uniform mesopore size.