Natural clay based nickel catalysts for dry reforming of methane: On the effect of support promotion (La, Al, Mn)

Fe modified natural clay supported Ni catalysts promoted with Lanthanum (La), aluminum (Al) and Manganese (Mn) were prepared by impregnation method. Calcined or reduced catalysts were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), H-2-temperature programmed reduction (H-2-TPR) and CO2-temperature programmed desorption (CO2-TPD). The addition of La, Al and Mn obviously affected the specific surface area and catalyst basicity. The presence of La, Al and Mn resulted in smaller Ni-0 crystallite size and further promoted Ni dispersion. Al-promoted catalysts improved the Ni reducibility compared to La and Mn-promoted catalysts. After a reduction step at 900 degrees C, the studied catalysts have been tested in dry reforming of methane (DRM) from 850 to 600 degrees C. Al-promoted Fe-clay based catalysts presented the best catalytic performance in DRM. Both CH4 and CO2 conversions, and H-2/CO molar ratio followed the trend of thermodynamic calculations. Furthermore all conversions and H-2/CO molar ratio were close to theoretical values that were also forecasted by thermodynamics by means of HSC Chemistry 5.0. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.