Catalytic steam and oxysteam reforming of methane to syngas studied involves coupling of exothermic oxidative conversion and endothermic steam-reforming processes over CoxNi1-xO (x = 0.0 - 0.5) supported on MgO precoated commercial low surface area ( < 0.01 mZ g(-1)) macroporous silica-alumina SA-5205 catalyst carrier The influence of the Co/Ni ratio of the catalyst on its performance in steam and oxysteam reforming processes (at 800 and 850 degreesC) was studied For the steam reforming process, the Co/Ni ratio influences strongly on the methane and steam conversion and CO selectivity and product H-2/CO ratio, particularly at lower temperature. When the Co/Ni ratio is increased, the methane and H2O conversion and CO selectivity are decreased markedly. For the oxysteam reforming process, the influence of the Co/Ni ratio on the performance is smaller and depends on process conditions. When the Co/Ni is increased, the methane conversion passes through a maximum at the Co/Ni ratio of 0.17 The influence of the reaction temperature (800 and 850 degreesC) and CH4/O-2 and CH4/H2O ratios on the conversion, selectivity, H-2/CO product ratio, and net reaction heat (DeltaH(r)) was studied in the oxysteam reforming (at space velocity of 47, 000 cm(3 .) g (- 1 .) h (-1)) over the catalyst with an optimum Co/Ni ratio (0.17) and a higher Co/Ni ratio (1.0). The oxysteam reforming process involves coupling the exothermic oxidative conversion of methane and the endothermic methane steam reforming reactions, making the process highly energy-efficient and nonhazardous. This process can he made thermoneutral, mildly exothermic, and mildly endothermic by manipulating process conditions.