Synthesis of mesoporous pseudoboehmite and alumina templated with 1-hexadecyl-2,3-dimethyl-imidazolium chloride

Synthesis of mesoporous pseudoboehmite and alumina in the reaction of aluminum tri-sec-butoxide with excess and deficient water using 1-hexadecyl-2,3-dimethyl-imidazolium chloride as a template is reported. The amount of water shows contrasted effects on morphology, crystal phase, and porosity for the resulting particles. In the case of excess water, the as-prepared particles are fibrous pseudoboehmite phase, which are almost destroyed at 550 °C and transformed into γ-Al2O3 after 800 °C calcination, together with change of particle morphology. The calcined samples have a textural porosity. In the case of deficient water, the as-prepared particles are amorphous and plate-shaped. They show framework porosity, with a narrow pore-size distribution after 550 °C calcination. These particles are also transformed into γ-Al2O3 at 800 °C, but the shape is retained. The 1-hexadecyl-2,3-dimethyl-imidazolium chloride molecules contained in the as-prepared samples can be removed before 550 °C.