Facile heterogeneously catalyzed nitrogen fixation by MXenes
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/28771 |
Resumo: | The rate-limiting step for ammonia (NH3) production via the Haber–Bosch process is the dissociation of molecular nitrogen (N2), which requires quite harsh working conditions, even when using appropriate heterogeneous catalysts. Here, motivated by the demonstrated enhanced chemical activity of MXenes— a class of two-dimensional inorganic materials— toward the adsorption of quite stable molecules such as CO2 and H2O, we use density functional theory including dispersion, to investigate the suitability of such MXene materials to catalyze N2 dissociation. Results show that MXenes exothermically adsorb N2, with rather large adsorption energies ranging from −1.11 to −3.45 eV and elongation of the N2 bond length by ∼20%, greatly facilitating their dissociation with energy barriers below 1 eV, reaching 0.28 eV in the most favorable studied case of W2N. Microkinetic simulations indicate that the first hydrogenation of adsorbed atomic nitrogen is feasible at low pressures and moderate temperatures, and that the production of NH3 may occur above 800 K on most studied MXenes, in particular, in W2N. These results reinforce the promising capabilities of MXenes to dissociate nitrogen and suggest combining them co-catalytically with Ru nanoparticles to further improve the efficiency of ammonia synthesis. |
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Facile heterogeneously catalyzed nitrogen fixation by MXenes2D MaterialsAdsorptionAmmonia SynthesisClean MXenesDensity functional theoryMetal Carbides and NitridesMicrokinetic ModelingThe rate-limiting step for ammonia (NH3) production via the Haber–Bosch process is the dissociation of molecular nitrogen (N2), which requires quite harsh working conditions, even when using appropriate heterogeneous catalysts. Here, motivated by the demonstrated enhanced chemical activity of MXenes— a class of two-dimensional inorganic materials— toward the adsorption of quite stable molecules such as CO2 and H2O, we use density functional theory including dispersion, to investigate the suitability of such MXene materials to catalyze N2 dissociation. Results show that MXenes exothermically adsorb N2, with rather large adsorption energies ranging from −1.11 to −3.45 eV and elongation of the N2 bond length by ∼20%, greatly facilitating their dissociation with energy barriers below 1 eV, reaching 0.28 eV in the most favorable studied case of W2N. Microkinetic simulations indicate that the first hydrogenation of adsorbed atomic nitrogen is feasible at low pressures and moderate temperatures, and that the production of NH3 may occur above 800 K on most studied MXenes, in particular, in W2N. These results reinforce the promising capabilities of MXenes to dissociate nitrogen and suggest combining them co-catalytically with Ru nanoparticles to further improve the efficiency of ammonia synthesis.American Chemical Society2020-07-01T09:35:56Z2020-05-01T00:00:00Z2020-05-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/28771eng2155-543510.1021/acscatal.0c00935Gouveia, José D.Morales-García, ÁngelViñes, FrancescGomes, José R. B.Illas, Francescinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:55:38Zoai:ria.ua.pt:10773/28771Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:01:14.138134Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
title |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
spellingShingle |
Facile heterogeneously catalyzed nitrogen fixation by MXenes Gouveia, José D. 2D Materials Adsorption Ammonia Synthesis Clean MXenes Density functional theory Metal Carbides and Nitrides Microkinetic Modeling |
title_short |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
title_full |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
title_fullStr |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
title_full_unstemmed |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
title_sort |
Facile heterogeneously catalyzed nitrogen fixation by MXenes |
author |
Gouveia, José D. |
author_facet |
Gouveia, José D. Morales-García, Ángel Viñes, Francesc Gomes, José R. B. Illas, Francesc |
author_role |
author |
author2 |
Morales-García, Ángel Viñes, Francesc Gomes, José R. B. Illas, Francesc |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Gouveia, José D. Morales-García, Ángel Viñes, Francesc Gomes, José R. B. Illas, Francesc |
dc.subject.por.fl_str_mv |
2D Materials Adsorption Ammonia Synthesis Clean MXenes Density functional theory Metal Carbides and Nitrides Microkinetic Modeling |
topic |
2D Materials Adsorption Ammonia Synthesis Clean MXenes Density functional theory Metal Carbides and Nitrides Microkinetic Modeling |
description |
The rate-limiting step for ammonia (NH3) production via the Haber–Bosch process is the dissociation of molecular nitrogen (N2), which requires quite harsh working conditions, even when using appropriate heterogeneous catalysts. Here, motivated by the demonstrated enhanced chemical activity of MXenes— a class of two-dimensional inorganic materials— toward the adsorption of quite stable molecules such as CO2 and H2O, we use density functional theory including dispersion, to investigate the suitability of such MXene materials to catalyze N2 dissociation. Results show that MXenes exothermically adsorb N2, with rather large adsorption energies ranging from −1.11 to −3.45 eV and elongation of the N2 bond length by ∼20%, greatly facilitating their dissociation with energy barriers below 1 eV, reaching 0.28 eV in the most favorable studied case of W2N. Microkinetic simulations indicate that the first hydrogenation of adsorbed atomic nitrogen is feasible at low pressures and moderate temperatures, and that the production of NH3 may occur above 800 K on most studied MXenes, in particular, in W2N. These results reinforce the promising capabilities of MXenes to dissociate nitrogen and suggest combining them co-catalytically with Ru nanoparticles to further improve the efficiency of ammonia synthesis. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-07-01T09:35:56Z 2020-05-01T00:00:00Z 2020-05-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/28771 |
url |
http://hdl.handle.net/10773/28771 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
2155-5435 10.1021/acscatal.0c00935 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799137667878748160 |