Magnetically recoverable support-free mesoporous Ni/NiO catalyst for conversion of oxygenates to fuels and chemicals

Abstract Mesoporous Ni/NiO with highest reported surface area among unsupported Ni/NiO catalyst is reported. The catalyst was prepared by chemical reduction in the presence of an organosilane template to stabilize the Ni/NiO structure and to create mesopores. Ni nanoparticles were embedded in NiO nanosheets. The material showed high surface area (282 m 2 /g) with 10–20 nm average Ni crystallite size and 20% metal dispersion. The concentration of Ni° in leached mesoporous Ni/NiO is 30% from XPS analysis, while 66% from EXAFS analysis. The catalyst showed intrinsic acidity of 0.2 mmol/g and ferromagnetic nature. Hydrodeoxygenation and hydrogenation reactions were studied. Nearly complete hydrodeoxygenation of methyl oleate and jatropha oil (99%), with >90% C9-C18 hydrocarbons selectivity, has been achieved. Hydrodeoxygenation of methyl oleate followed pseudo-first-order kinetics, and the activation energy was calculated as 48 kJ/mol. Nearly complete phenol hydrogenation (99%), and 100% selectivity for cyclohexanol was obtained. The activity of mesoporous leached Ni/NiO was found to be higher than the supported Pd and Ni catalysts due to desirable structure, high metal dispersion, large surface area, and high porosity.