Application of hollow promoted Ni-based catalysts in steam methane reforming

This work deals with the application of Y-promoted Ni-based catalysts supported on both bulk and hollow Al2O3 supports with spherical shape in the steam reforming of methane (SRM) process. For evaluating the influence of Ni and Y loadings, 15, 20, and 25 wt% Ni and 1.5, 3.0, and 4.5 wt% Y were loaded on both alumina supports. Furthermore, for enhancing the stability and activity of SRM Ni-based catalysts, reaction temperature (600, 650, and 700 degrees C) and steam to methane (S/M) molar ratio (1.5 to 3.0) are also adjusted in this research. Various characterizing techniques listed as X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), N2 adsorption/desorption, energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), H2 temperature programmed reduction (H2-TPR), and temperature programmed oxidation (TPO) were employed on the fresh and used catalyst. Improvements in metal dispersion, catalytic performance, and long-time stability in SRM were achieved with the aim of a hollow Ni-Y-Al catalyst. As a result, 20Ni-3.0Y/HAl depicted the highest methane conversion of 95.77 %, hydrogen yield of 97.74 %, and H2/CO molar ratio of 6.61 at 700 degrees C, which is probably due to the higher surface area of hollow alumina support in comparison with bulk one.