Monitoring by in situ NAP-XPS of active sites for CO2 methanation on a Ni/CeO2 catalyst
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Título: | Monitoring by in situ NAP-XPS of active sites for CO2 methanation on a Ni/CeO2 catalyst |
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Autor/es: | López-Rodríguez, Sergio | Davó-Quiñonero, Arantxa | Bailón-García, Esther | Lozano-Castello, Dolores | Villar-Garcia, Ignacio J. | Perez Dieste, Virginia | Onrubia-Calvo, Jon A. | González-Velasco, Juan R. | Bueno López, Agustín |
Grupo/s de investigación o GITE: | Materiales Carbonosos y Medio Ambiente |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Química Inorgánica |
Palabras clave: | CO2 methanation | Ceria | Nickel | NAP–XPS | Redox active sites |
Área/s de conocimiento: | Química Inorgánica |
Fecha de publicación: | 24-mar-2022 |
Editor: | Elsevier |
Cita bibliográfica: | Journal of CO2 Utilization. 2022, 60: 101980. https://doi.org/10.1016/j.jcou.2022.101980 |
Resumen: | Ni/CeO2 catalysts are very active and selective for total hydrogenation of CO2 to methane, but the nature of the active sites is still unclear. The surface of a Ni/CeO2 catalyst has been monitored under CO2 methanation conditions by Near Ambient Pressure-XPS (NAP-XPS) using synchrotron radiation, and has been concluded that the species involved in the redox processes taking place during the CO2 methanation mechanism are the Ni2+-CeO2/Ni0 and Ce4+/Ce3+ pairs. In addition, a small fraction of nickel is present on the catalyst surface forming NiO and Ni2+-carbonates/hydroxyls (around 20% of the total surface nickel), but these species do not participate in the redox processes of the methanation mechanism. Under CO2 methanation conditions the H2 reduction rate of the Ni2+-CeO2/Ni0 and Ce4+/Ce3+ couples is much faster than their CO2 reoxidation rate (2 times faster, at least, at 300ºC), but a certain proportion of nickel always remains oxidized under reaction conditions. The high activity of Ni/CeO2 catalysts for CO2 methanation is tentatively attributed to the simultaneous presence of Ni2+-CeO2 and Ni0 active sites where CO2 and H2 are expected to be efficiently dissociated, respectively. |
Patrocinador/es: | Generalitat Valenciana, Spain (PROMETEO/2018/0765) Ministry for Science and Innovation MICINN, Spain (Projects PID2019-105960RB-C21 and PID2019-105960RB-C22) Junta de Andalucía, Spain (Project P18-RTJ-2974); European Union’s Horizon 2020 Research and Innovation Program (Marie Skłodowska-Curie grant agreement No 713567) Science Foundation Ireland Research Centre, Ireland (award 12/RC/2278_P2) ALBA synchrotron, Spain (Proposal number: ID 2020094556). |
URI: | http://hdl.handle.net/10045/122324 |
ISSN: | 2212-9820 (Print) | 2212-9839 (Online) |
DOI: | 10.1016/j.jcou.2022.101980 |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/article |
Derechos: | © 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Revisión científica: | si |
Versión del editor: | https://doi.org/10.1016/j.jcou.2022.101980 |
Aparece en las colecciones: | Investigaciones financiadas por la UE INV - MCMA - Artículos de Revistas |
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