Preparation of sol-gel derived nickel/gamma-alumina catalytic membrane and its application to methanol-to-hydrogen converter characterization of composite sol and gel

Nickel/bochmite composite gels are prepared from stable sols of different nickel compositions. The particle size in the sols is measured by dynamic light scattering, and the nanostructure of the gels is characterized by nitrogen adsorption, FE-SEM, thermal analysis, XRD and gas permeation. By firing the composite gels, nickel/γ-alumina catalysts are prepared, and the catalytic activity in methanol decomposition (CH₃OH → CO + 2H₂) is studied. The nanostructure and the catalytic performance strongly depend on the nickel content. These results reveal that nickel is classified into two species; nickel effective for nanostructure control and active in methanol decomposition. A pinhole-free composite thin membrane is formed on a porous ceramic support, and the performance as a methanol-to-hydrogen converter is tested.