Carbon dioxide methanation using Ni catalysts supported on low-cost Lynde Type A zeolite synthesized from pretreated Iranian coal gangue

Coal gangue is solid waste generated from coal mining. Reducing carbon dioxide emissions is a challenge to mitigate the problems caused by global warming. In this work, zeolite LTA-5A is synthesized for the first time from the coal gangue of Iranian mines and used as catalyst support for preparing nickel catalysts for carbon dioxide methanation. These catalysts are characterized using XRD, FESEM, SEM, TEM, EDX, elemental mapping, H2-TPR, 2-TPR, CO2-TPD, 2-TPD, TGA, and low-temperature nitrogen adsorption. The methanation tests reveal that the 15% NiCGLTA-5A has the best catalytic performance among the catalysts, showing 73 +/- 2% CO2 2 conversion and 91 +/- 2% CH4 4 selectivity at 450 degrees C. The performance of these catalysts is comparable to those prepared from fly ash. Using coal gangue, an industrial waste with many environmental problems, as the primary source of silicon and aluminum can create a positive economic and ecological impact.