Investigation of the effect of cobalt on the Ni–Al2O3 catalyst prepared by the mechanochemical method for CO2 methanation

Various Ni–Co catalysts supported on alumina were produced by the mechanochemical technique and applied to CO2 Methanation. X-ray diffraction, temperature-programmed reduction with H2 (H2–TPR), and nitrogen physisorption were used to characterize the produced catalysts. The results of investigating three active phase percentages of Ni–Co, including 10%, 15%, and 20%, showed that the activity of Ni-based catalysts was affected with the cobalt addition. The introduction of Co improved the dispersion of Ni particles in the catalyst, and the incorporation of cobalt into the Ni–Al2O3 caused a decline in the surface area and an increase in crystal size. The effect of adding equal amounts of 5, 10, and 15% Co to 5 N, 10 N, and 15 N was also investigated in this study. The changes in the molar ratios of Ni/Co had a remarkable effect on the performance of the catalyst at temperatures from 200 to 500 °C. From our results on the effect of adding an equal amount of 5, 10, and 15% Co to 5 N, 10 N, and 15 N, it can be concluded that the 10N10C catalyst is more active than 10Ni while 5N5C and 15N15C showed lower activities than 5 N and 15 N.