Synthesis of Cr_2O_3-Al_2O_3 powders with various Cr_2O_3/Al_2O_3 molar ratios and their applications as support for the preparation of nickel catalysts in CO_2 methanation reaction

摘要

The Methanation of CO2 to CH4 is a significant route to save energy and reduce CO2 emission. In this work, a series of Cr2O3-Al2O3 powders were synthesized by a novel and simple solid-state method and considered as the carrier for the nickel catalysts in CO2 methanation. The BET area and pore volume of the supports decreased with the decrease in Al2O3/Cr2O3 molar ratio. The results indicated that the increase in Cr2O3 content improved the catalytic performance and 15 wt%Ni/Cr2O3 catalyst exhibited the highest CO2 conversion of 80.51%, and 100% CH4 selectivity at 350 degrees C. The results indicated that the CO2 conversion improved with the increment in H-2/CO2 molar ratio from 2 to 5. The improvement in CO2 conversion was also observed with decreasing GHSV due to the longer residence time of the reactants on the catalyst surface. Also, the results showed that increasing calcination temperature led to a decrease in CO2 conversion. The 15 wt%Ni/Cr2O3 catalyst exhibited high stability in carbon dioxide methanation reaction. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.