Samarium-impregnated nickel catalysts over SBA-15 in steam reforming of CH4 process
Promoted Ni/SBA-15 catalysts with varying amounts of Sm promoter (0.5, 1.5, 3 and 6 wt.%) were prepared and employed in steam reforming of methane (SRM) process. The catalysts were synthesized by a two-solvent impregnation method and characterized by low and high angles XRD, BET, TPO, TEM, ED, and FE-SEM techniques. The results demonstrated that increasing in Sm content from 0.5 to 3 wt.% diminished the specific surface area of catalysts from 504 to 371 m2/g and decreased the average nickel crystallite size from 31 to 12 nm. The catalytic results exhibited that adding Sm promoter enhanced the catalytic activity from 31% in unprompted catalyst to 70% for 3 wt.% Sm-promoted catalyst. Also, the catalyst with 3 wt.% of Sm possessed the highest H2 production yield, about 66%. In addition, the TPO, TEM and ED tests revealed the formation of carbon with nanotube nature on the catalyst surface.