Enhanced low-temperature activity of CO2 methanation over ceria-promoted Ni-Al2O3 nanocatalyst

Abstract

The present article, the influence of promoters (Zr, Ce, La, and Mo) on the structural properties and low temperature activity features of Ni-Al2O3 catalyst has been addressed in CO2 methanation reaction. The catalysts were made ready by the ultrasound assisted co-precipitated procedure and their features were described through XRD, H2-TPR, BET, SEM, CO2-TPD, TGA/DTA, and TPO techniques. The H2-TPR analysis showed the addition of promoters leading to the stronger interaction between nickel species and alumina, resulting in the formation of smaller crystallite size. Among the promoters, ceria can positively affect the catalytic performance of Ni-Al2O3 catalyst in CO2 methanation. The characterization results revealed that adding ceria favored the dispersion of NiO species, reduced Ni particle size, and increased the metal-support interaction. The 25wt.%Ni-5wt.%CeO2-Al2O3 catalyst possessed the superior catalytic activity and stability that attained the maximum CO2 conversion of 76.4% and CH4 selectivity of 99.1% at 350 °C.