CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations

Two types of single-atom Si-embedded N-doped graphene sheets, denoted as SiNxC3−x and SiNxC4−x, were designed for CO2 activation and electroreduction. The first-principles calculations show that CO2 can be chemically adsorbed at the single-atom Si sites of SiN1C2, SiN2C1, SiN3C0, SiN3C1, and SiN4C0...

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Autores principales:	Lei Fang, Zexing Cao
Formato:	article
Lenguaje:	EN
Publicado:	AIP Publishing LLC 2021
Materias:	Physics QC1-999
Acceso en línea:	https://doaj.org/article/5596540b9f574a43b2c4d07e3832724e
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spelling	oai:doaj.org-article:5596540b9f574a43b2c4d07e3832724e2021-12-01T18:52:06ZCO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations2158-322610.1063/5.0067934https://doaj.org/article/5596540b9f574a43b2c4d07e3832724e2021-11-01T00:00:00Zhttp://dx.doi.org/10.1063/5.0067934https://doaj.org/toc/2158-3226Two types of single-atom Si-embedded N-doped graphene sheets, denoted as SiNxC3−x and SiNxC4−x, were designed for CO2 activation and electroreduction. The first-principles calculations show that CO2 can be chemically adsorbed at the single-atom Si sites of SiN1C2, SiN2C1, SiN3C0, SiN3C1, and SiN4C0 monolayers with quite low-energy barriers and exothermicity to some extent. Unexpectedly, CO2 activation and capture at the atomically dispersed Si sites of SiNxC3−x and SiNxC4−x follow different electron mechanisms where the three-coordinated Si in SiNxC3−x behaves as an electron donor while the four-coordinated Si acts as an electron shuttle for the electron transfer from the SiNxC4−x framework to CO2. For SiNxC4−x, the low-energy Si-pz center is a prerequisite for the Si site to capture the electron from the support framework, which is beneficial for the electron transfer to CO2. The activity of SiNxC3−x depends on both the Si-pz band center and the electron population at the three-coordinated Si, resulting in the conventional linear correlation between the activity and the p-band center not being observed. Furthermore, the SiN3C0 sheet is predicted to be quite a promising electrode material for CO2 electrochemical reduction to HCOOH, CH3OH, and CH4 with quite low limiting potentials.Lei FangZexing CaoAIP Publishing LLCarticlePhysicsQC1-999ENAIP Advances, Vol 11, Iss 11, Pp 115302-115302-7 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Physics QC1-999
spellingShingle	Physics QC1-999 Lei Fang Zexing Cao CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
description	Two types of single-atom Si-embedded N-doped graphene sheets, denoted as SiNxC3−x and SiNxC4−x, were designed for CO2 activation and electroreduction. The first-principles calculations show that CO2 can be chemically adsorbed at the single-atom Si sites of SiN1C2, SiN2C1, SiN3C0, SiN3C1, and SiN4C0 monolayers with quite low-energy barriers and exothermicity to some extent. Unexpectedly, CO2 activation and capture at the atomically dispersed Si sites of SiNxC3−x and SiNxC4−x follow different electron mechanisms where the three-coordinated Si in SiNxC3−x behaves as an electron donor while the four-coordinated Si acts as an electron shuttle for the electron transfer from the SiNxC4−x framework to CO2. For SiNxC4−x, the low-energy Si-pz center is a prerequisite for the Si site to capture the electron from the support framework, which is beneficial for the electron transfer to CO2. The activity of SiNxC3−x depends on both the Si-pz band center and the electron population at the three-coordinated Si, resulting in the conventional linear correlation between the activity and the p-band center not being observed. Furthermore, the SiN3C0 sheet is predicted to be quite a promising electrode material for CO2 electrochemical reduction to HCOOH, CH3OH, and CH4 with quite low limiting potentials.
format	article
author	Lei Fang Zexing Cao
author_facet	Lei Fang Zexing Cao
author_sort	Lei Fang
title	CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
title_short	CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
title_full	CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
title_fullStr	CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
title_full_unstemmed	CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations
title_sort	co2 activation at atomically dispersed si sites of n-doped graphenes: insight into distinct electron mechanisms from first-principles calculations
publisher	AIP Publishing LLC
publishDate	2021
url	https://doaj.org/article/5596540b9f574a43b2c4d07e3832724e
work_keys_str_mv	AT leifang co2activationatatomicallydispersedsisitesofndopedgraphenesinsightintodistinctelectronmechanismsfromfirstprinciplescalculations AT zexingcao co2activationatatomicallydispersedsisitesofndopedgraphenesinsightintodistinctelectronmechanismsfromfirstprinciplescalculations
_version_	1718404692457816064

CO2 activation at atomically dispersed Si sites of N-doped graphenes: Insight into distinct electron mechanisms from first-principles calculations

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