A co-current dropwise addition method was employed to prepare γ-alumina with a large pore volume with sodium aluminate (NaAlO2) and aluminum sulfate (Al2(SO4)3) used as raw materials. The effects of the reaction pH during the precipitation process

raw material concentration

aging pH and adding surfactant sodium dodecyl benzene sulfonate (SDBS) were investigated. It was found that raw material concentration could affect the nucleation-growth process and result in different morphologies

such as irregular sheets

fibers or granules

in which fibers could form the largest pore volume. When the NaAlO2 concentration was 0.5-0.75 mol/L

the reaction pH was controlled at 8-9.5 and the aging pH was controlled at about 9

the obtained γ-alumina is fibrous. Besides

adding SDBS during the aging process could further improve the pore volume and pore size distribution. The method successfully prepared fibrous γ-alumina with a pore volume of 1.35-2.19 ml/g

a specific surface area of 300-500 m2/g and an average pore diameter of 14-21 nm

a fiber length of 50-60 nm and diameter about 5 nm. It can provide a good catalyst carrier for the residue hydrogenation process.