In this study, biopolymer chitosan is presented as a template for synthesizing and shaping the mesoporous γ‐Al2O3 macrospheres. This porous γ‐Al2O3 granule has a high surface area (310 m2/g), high pore volume (.6148 cm3/g), and pore diameter between 2 and 10 nm. The full factorial design based on a mathematical model was implemented to study the acid concentration, chitosan amount, ammonia concentration, and aging time affecting the responses (Brunauer–Emmett–Teller surface area and pore volume). Predicted responses were found to be in satisfactory agreement with experimental values (R2 = .9580 and .9109, respectively). The adequacy of the model was examined by analyzing the residual distribution plots and Pareto graph. X‐ray diffraction, scanning electron microscopy (SEM), thermogravimetric analysis, and N2 adsorption/desorption techniques are employed to characterize the structure of the prepared γ‐alumina sample.

Sol-gel/oil-drop granulation technique was used to prepare mesoporous ?-Al2O3 granules of 1.5-2mm with high specific surface area and pore volume of 295m2/g and 0.47 cm3/g, respectively. The structure of granules was studied using powder XRD, DTA, TEM and N2 adsorption/desorption techniques. A response surface methodology (RSM) holding CCD approach was used for modelling the influence of process variables on the granule pore structure, having a quadratic function relating the independent variables (calcination temperature, acid amount and ammonia concentration) to the responses (specific surface area, mean pore diameter and pore volume). The interaction effect of variables on each response was studied and all were in acceptable accordance with experimental values. Accordingly, the granules synthesized using 20ml of nitric acid, aged in a 9.25wt.% ammonia solution and calcined at 450?C showed the best properties. The predicted values for the specific surface area and pore volume were 315.64m2/g, 7 nm and 0.53 cm3/g, respectively, which were compatible with experimental values.