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

Abstract

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·gcat) 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.