Influence of Fe, La, Zr, Ce, and Ca on the catalytic performance and coke formation in dry reforming of methane over Ni/MgO.Al2O3 catalyst

Abstract

The catalytic and structural properties of the mesoporous nanocrystalline 10 wt.% Ni–MeOx (Me= Fe, La, Zr, Ce, Ca)-MgAl2O4 catalysts were investigated in dry reforming of methane. The catalysts were synthesized simultaneously via a simple and novel surfactant-free self-assembly sol-gel method. The prepared samples with different promoters showed the high surface area ranging from 283.61 to 312.86m2/g. The characterization of prepared catalysts was determined using different BET, XRD, SEM, TPR and TPO analysis. The addition of Ce to Ni/MgAl2O4 dramatically improved the catalytic performance and the Ce-promoted catalysts exhibited the highest CH4 conversion among the promoted and unpromoted catalysts. Also Ce suppressed the carbon deposition because CeO2 enhanced the Ni dispersion and reactivity of carbon deposits. The findings of the study showed 3 wt. % Ce promoted catalysts exhibited the best performance in temperature and stability test, more than 50% CH4 with a lower amount of deposited carbon among other powders in dry reforming reaction. Also, no deactivation was observed for this catalyst at a period of 900 minutes of time on stream and at the special condition which despite high feed ratio CH4/CO2=2 and the high GHSV=24000 mL h-1 g-1cat.