Partial oxidation of methane was studied over new Ni nanocatalysts prepared from Ni-impregnated gamma-AlOOH, which were compared with their counterparts derived from impregnated gamma-Al(2)O(3)and alpha-Al2O3. The prepared catalysts were characterized by powder X-ray diffraction (XRD), N-2-sorption, H-2-temperatue programmed reduction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, CO2- and NH3-temperature-programmed desorption, Raman spectroscopy, CO chemisorption, and diffuse reflectance infrared Fourier transform spectroscopy of adsorbed CO. Employing gamma-AlOOH as the support precursor resulted in significantly improved textural properties and catalytic activity. The structure of the support precursor and its surface properties showed a strong influence on the type of Ni active species and their interactions with the support. gamma-AlOOH-derived catalysts showed NiO as the dominant Ni species when calcined at 500 degrees C to 650 degrees C, while NiAl(2)O(4)became the sole phase at higher temperatures. On the other hand, mixtures of NiO and NiAl(2)O(4)formed over gamma-Al2O3, calcined before impregnation, regardless of the precalcination temperature. All gamma-AlOOH-derived catalysts showed higher specific surface areas compared to their counterparts derived from impregnated gamma-Al2O3. Upon calcination at moderate temperatures, gamma-AlOOH-derived catalysts also showed modified textural and morphological properties of the Ni active particles, including higher Ni dispersion, larger metal surface area, and smaller Ni crystallites. The support precursor and the pretreatment conditions showed a strong influence on the catalytic performance, which was referred to their significant effect on the type of the Ni species and interactions with the support. All catalysts showed higher catalytic activity than the alpha-Al2O3-derived catalyst, with CH(4)conversion between 86% and 88.5% at 700 degrees C. While gamma-AlOOH- and gamma-Al2O3-derived catalysts calcined at 650 degrees C showed a stable CH(4)conversion around 88%, and higher syngas selectivity than the other catalysts, Ni/gamma-AlOOH-650 showed the highest selectivity to syngas, with a H-2/CO ratio very close to 2.0. The improved Ni dispersion and the enhanced syngas selectivity obtained in the preset work demonstrate that using gamma-AlOOH as a support precursor holds a great promise for the development of a new route for more efficient Ni catalysts compared with the widely studied gamma-Al(2)O(3)and alpha-Al(2)O(3)support precursors.