A novel method for synthesis of a Ni/Al₂O₃ catalyst with a mesoporous structure using stearic acid salts

Nickel stearate was used as a chemical template and metal source for the easy-and-fast preparation of Ni/Al₂O₃ catalyst with a mesoporous structure. Ni-Nx and Ni-Hx were prepared using an NH ₄OH-treated precipitate and a HCl-treated solution as the chemical template, respectively, and these materials show only the effect of the chemical template, a regular pore size distribution. Ni-Nx with both a developed framework and textural porosity show a larger surface area and pore volume but a less irregular pore structure than Ni-Hx which shows a well-developed framework porosity. The ²⁷Al NMR MAS analysis showed that nickel oxide supported on active alumina allows Ni²⁺ ions to diffuse into the surface lattice vacancies of the alumina spinel structure. Such a migration of metal ions may be limited to the first few layers of the supports, but leads to the production of hard-to-reduce metal oxide (i.e. a high metal-to-support interaction). Ni-Nx was also found to have a more dispersed nickel particle configuration than Ni-Hx after reduction.