Effective CO2 methanation at ambient pressure over Lanthanides (La/Ce/Pr/Sm) modified cobalt-palygorskite composites

Abstract

Hear a series of Lanthanide-modified cobalt-palygorskite composite (LnCoPal, LnLa/Ce/Pr/Sm) for CO2 methanation reaction under atmospheric pressure were prepared by a simple impregnation method. The results showed that the PrCoPal catalyst showed fairly good activity for CO2 methanation, the CO2 conversion rate was 68.05% and the CH4 selectivity was 95.0% at 425 °C and atmospheric pressure (GHSV=15,000). The improved catalytic performance for the PrCoPal composite materials, compared to the other elements doped samples, was attributed to the incorporation of the Pr elements into the Co/Pal system, which enhanced the metal-support interaction between Co and palygorskite (Pal), improved the dispersibility of Co particles on Pal, refined Co particles, and increased catalytically active sites on the surface of the catalyst. The surface modification with a small amount of lanthanides slightly increased the surface alkalinity, enhanced the adsorption of CO2, and improved the overall catalytic performance.