CO2 conversion to methane using Ni/SiO2 catalysts promoted by Fe, Co and Zn

• Published in: Journal of environmental chemical engineering Vol. 9; no. 1; p. 104629
• Main Authors: Dias, Yan Resing, Perez-Lopez, Oscar W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2021
• Subjects: Carbon dioxide conversion; Energy storage; Metal promotion; Methanation; Ni/SiO2 catalyst; Methanation; Ni/SiO2 catalyst; Carbon dioxide conversion; Metal promotion; Energy storage
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2020.104629

[Display omitted] •Fe, Co and Zn promoted Ni/SiO2 catalysts were evaluated in CO2 methanation.•Fe and Co enhanced significantly both CO2 conversion and CH4 selectivity.•Zn promoted catalyst decreases the CO2 conversion and increases the CO selectivity.•Co decreases the catalyst sintering whereas Fe decreases the carbon deposition.•Ni/SiO2 catalysts promoted by Co and Fe show high potential for the CO2 methanation. Mitigation of CO2 emissions has become an important issue nowadays, as well as its reutilization as a carbon source to obtain chemicals and fuels. CO2 conversion to CH4 comes up as an interesting alternative, since it is a natural gas substitute and H2 storage source. In this study, Ni/SiO2 catalysts promoted by Fe, Co and Zn were prepared by simple wet impregnation and evaluated in the CO2 conversion to methane. The samples were characterized by TGA-DTA, XRD, N2 physisorption, H2-TPR and TPO-DTA. The reactions were carried out at 1 atm in a fixed bed reactor with H2/CO2 = 4 and online GC analysis. The addition of a second metal enhanced the surface area and lowered the Ni° crystallite size, indicating that metallic dispersion was improved. These characteristics had positive influence on the methanation performance of the Fe and Co promoted catalysts, which showed improved CO2 conversion and CH4 selectivity in comparison to unpromoted catalysts. Ni-Co/SiO2 presented the best results, attaining 73 % of CO2 conversion and 98.5 % of CH4 selectivity at 350 °C and high resistance to sintering. The catalyst promoted by Fe presented the higher resistance to carbon formation, whereas the promotion with Zn led to a strong decrease in selectivity for CH4 and a consequent increase in selectivity for CO. These results suggest the use of both Fe and Co as promoters of Ni/SiO2 catalysts has a high potential for the CO2 conversion to CH4.