Effects of Ce, La, Cu, and Fe promoters on Ni/MgAl₂O₄ catalysts in steam reforming of propane

The effects of nickel loading and type of promoter on the performance of xNi/MgAl₂O₄ (x=5, 10, and 15 wt%) and 10Ni-3M/MgAl₂O₄ (M=Ce, La, Cu, Fe) catalysts, respectively, in steam reforming of propane (SRP) were investigated. The catalyst support (MgAl₂O₄) was synthesized by co-precipitation method with a MgO/Al₂O₃ mole ratio of 1.0. The catalysts were then prepared by impregnation of nitrates of nickel and promoters on the support. The catalysts were characterized by the XRD, nitrogen adsorption-desorption, TPR, SEM, EDX mapping, and TGA, and the SRP performance was evaluated in a fixed bed reactor at reaction temperature=500–700 °C, pressure=1 atm, C₃H₈:N₂: steam feed ratio=1:1:3, and GHSV=30,000 ml/(h·g_cat) during 420 min time on stream. The results indicated that C₃H₈ conversion, H₂ yield, and catalyst stability varied significantly with nickel loading and type of promoter in the catalyst. The 10Ni/MgAl₂O₄ catalyst showed highest C3H8 conversion (78%), H2 yield (49%), and stability (96%) as compared to the other unpromoted catalysts due to optimum nickel loading and less carbon deposition. Moreover, cerium promoter remarkably enhanced the performance of 10Ni-3Ce/MgAl₂O₄ catalyst (C₃H₈ conversion=93%, H₂ yield=60%, and stability= 100%) via more coke gasification in the course of SRP reaction.