2026-09-15T23:40:58Zhttps://gredos.usal.es/oai/request

oai:gredos.usal.es:10366/1531862025-04-30T19:51:00Zcom_10366_4164com_10366_4055com_10366_3946com_10366_3823col_10366_4165

Lechkar, Ali Blanco, Ginesa Pintado, José María Soussi el Begrani, Mohamed Bogeat Barroso, Adrián 2023-10-06T07:21:29Z 2023-10-06T07:21:29Z 2018 Lechkar, A., Barroso-Bogeat, A., Blanco, G., Pintado, J., Soussi el Begrani, M. (2018). Methanation of carbon dioxide over ceria-praseodymia promoted Nialumina catalysts. Influence of metal loading, promoter composition and alumina modifier, Fuel, 234 pp 1401-1413. https://doi.org/10.1016/j.fuel.2018.07.157 0016-2361 http://hdl.handle.net/10366/153186 10.1016/j.fuel.2018.07.157 [EN] Two series of ceria-praseodymia promoted Ni-alumina catalysts were prepared from two different commercial modified alumina supports (3.5 wt% SiO2-Al2O3 and 4.0 wt% La2O3-Al2O3) by the incipient wetness impregnation method in two successive steps. The resulting materials were characterized in terms of their physicochemical properties by means of N2 physical adsorption at −196 °C, powder X-ray diffraction (XRD) and temperature programmed reduction with H2 (H2-TPR). Furthermore, the as-prepared catalysts were tested for the CO2 methanation reaction in a fixed-bed reactor at atmospheric pressure, gas hourly space velocity (GHSV) of 72,000 cm3·(h·gcat)−1 and CO2/H2 molar ratio of 1/4 over the temperature range from 25 up to 850 °C. The influence of the nominal Ni loading (3, 5 and 10 wt%), molar composition of the Ce/Pr mixed oxide promoter (80/20 and 60/40), and alumina modifier (silica and lanthana) on the catalytic performance was carefully analyzed. Among these three composition parameters, the alumina dopant and especially the Ni content appear to have by far a much more pronounced effect on both the CO2 conversion and CH4 selectivity as compared to the Ce/Pr mixed oxide composition. Specifically, from the catalytic tests the sample containing a 10 wt% Ni loading, a Ce/Pr mixed oxide promoter of 80/20 molar composition, and silica as modifier provides the highest catalytic activity in terms of CO2 conversion and CH4 selectivity. Such behaviour has been ascribed to a complex interplay between several factors, mainly the larger fraction of catalytically active β-type NiO species eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional CO2 methanation Ni-alumina catalysts Ceria-praseodymia promoter Modified alumina support Methanation of carbon dioxide over ceria-praseodymia promoted Ni-alumina catalysts. Influence of metal loading, promoter composition and alumina modifier info:eu-repo/semantics/article