Influence of temperature, surface composition and electrochemical environment on 2-propanol decomposition at the Co<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msub><mml:mrow/><mml:mn>3</mml:mn></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"><mml:msub><mml:mrow/><mml:mn>4</mml:mn></mml:msub></mml:math> (001)/H<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mm

Omranpoor, Amir H.; Kox, Tim; Spohr, Eckhard; Kenmoe, Stéphane

doi:10.1016/j.apsadv.2022.100319

Cited by 7 publications

(4 citation statements)

References 29 publications

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“…We considered the B-termination of the Co 3 O 4 (001) surface in an oxidative environment, which as mentioned in our previous molecular dynamics study 19 , was created by removing 8 hydrogen atoms from the water film in contact with the surface and the solutes. Out of the total MD simulation time of 20 ps, snapshots of the three main oxidation steps corresponding to the formation of 2-propanol, 2-propoxide, and acetone, respectively, were selected, and the electronic properties of the corresponding configurations were analyzed.…”

Section: Computational Detailsmentioning

confidence: 99%

“…Snapshots of equilibrium trajectories of (a) 2-propanol, (b) 2-propoxide, and (c) acetone molecules on the B-terminated Co 3 O 4 (001) surface in a humid environment (taken from ref ). For the sake of better visualization, only water molecules in the contact layer and at the vicinity of the adsorption site are shown.…”

Section: Computational Detailsmentioning

confidence: 99%

“…The B-termination ended by Co 3+ atoms and oxygen atoms was found to be the catalytically relevant facet in oxidative conditions and at room temperature. We observed that oxidation occurs via a three-step process: molecular adsorption on 2-propanol on Co 3+ sites, deprotonation of the alcoholic O and formation of 2-propoxide and dehydrogenation of the carbonyl group, and formation of acetone on the same active site …”

Section: Introductionmentioning

confidence: 97%

“…We observed that oxidation occurs via a three-step process: molecular adsorption on 2-propanol on Co 3+ sites, deprotonation of the alcoholic O and formation of 2-propoxide and dehydrogenation of the carbonyl group, and formation of acetone on the same active site. 19 However, this study only addressed the dynamics of the systems and the changes in characteristic geometrical features and bond lengths to exteriorize the decomposition of the 2propanol molecule. For a clear picture of the oxidation process, deeper insight on the nature of the active sites, namely their electronic properties and the reaction mechanisms, should be provided.…”

Section: Introductionmentioning

confidence: 99%

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Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

et al. 2023

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We use theoretical X-ray absorption near-edge spectroscopy (XANES) to investigate the electronic structure of the active sites on the Co3O4 (001) surface during 2-propanol oxidation to acetone in humid conditions. In the gas phase, the O K-edge spectra of 2-propanol and acetone, as well that of 2-propoxide considered as a reaction intermediate, present no pre-edge peaks. Upon 2-propanol adsorption at the Co site of the Co3O4 (001) surface, the O K-edge spectrum presents a distinct peak preceded by a bump in the pre-edge region, both due to dipole transitions from O 1s to 2p states hybridized with Co 3d empty states. The formation of 2-propoxide leads to two distinct pre-edge peaks due to the increase of 3d empty states. A further increment of these pre-edge peaks is observed when acetone is formed and is rather ascribed to the new contributions of carbon 2p empty states in the transitions occurring in the pre-edge region. The changes observed in the pre-edge peak along the oxidation were correlated to the electronic configuration and hybridization of the cobalt atom directly bonded to alcohol. The variation of electron densities was also monitored for all surface cobalt atoms including the ones on which molecular water and dissociated water are adsorbed. The PDOS analysis and crystal field theory showed that adsorption of 2-propanol and molecular water on the surface does not change the oxidation state of +3, while surface cobalt atoms bonded to OH groups have an oxidation state of +4. The 3d Löwdin charges analysis shows pronounced cooperative effects between both Co sites during the last oxidation step which corresponds to the decomposition of 2-propoxide to acetone.

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Section: Computational Detailsmentioning

confidence: 99%

Section: Computational Detailsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

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Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

et al. 2023

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Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn3O4) spherical particles

Ndouka,

Kenmoe,

Mache

et al. 2024

ChemPhysMater

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Atomic-Scale Understanding of Electrified Interfacial Structures and Dynamics during the Oxygen Reduction Reaction on the Fe–N₄/C Electrocatalyst

Wang,

Yan,

Cao

et al. 2023

ACS Catal.

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Understanding electric double layers (EDLs) and electrochemical processes represents significant challenges in electrocatalysis. In this study, we employed classic molecular dynamics (MD) and ab initio molecular dynamics (AIMD) simulations with an explicit water solvent to investigate interfacial structures on the Fe−N 4 −C catalyst and acquire dynamic observation of the oxygen reduction reaction (ORR). The orientation and population of interfacial water are potentialdependent. When potential shifts positively, water molecules evolve from structurally "two O−H down" to 'one O−H parallel, one O− H down,' "two O−H parallel," and eventually to "two O−H up." Our finding also suggests that hydrogen bonds (denoted as Hbonds) vary depending on the potential and follow an asymmetric M-shape pattern. It confirms that interfacial water with "two O−H parallel" structures maximizes the number of hydrogen bonds (Hbonds), while more water with 'one O−H down, one O−H up' suppresses H-bond formation. We provided detailed information on how the electrode potential influences H-bonds by impacting the orientations of interfacial water molecules. The above analysis of interfacial water is completely general and could be applicable to any water-based energy conversion and storage systems. Then, we focused on the reaction process and local environments around the ORR reaction center. Our simulations show that the proton transfer to oxygenous intermediates directly occurs at the applied potential. We also demonstrate that the applied potential induces charge redistribution and water reorientation around the reaction center. We further identified a quadratic function relationship between the reaction free energy/activation barrier and the potential for the key elementary ORR steps, in which the hydrogenation of the oxygenous intermediate is less favorable at higher potentials as the local water is stabilized and pulled away from the reaction center through the H-bond interaction. Our analysis provides a profound understanding of electric double layers and electrochemical processes, which are critical to experimental exploration and electrocatalyst application.

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Influence of temperature, surface composition and electrochemical environment on 2-propanol decomposition at the Co3O4 (001)/H2

Cited by 7 publications

References 29 publications

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn3O4) spherical particles

Atomic-Scale Understanding of Electrified Interfacial Structures and Dynamics during the Oxygen Reduction Reaction on the Fe–N₄/C Electrocatalyst

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Influence of temperature, surface composition and electrochemical environment on 2-propanol decomposition at the Co3O4 (001)/H2

Cited by 7 publications

References 29 publications

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co3O4 (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co3O4 (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn3O4) spherical particles

Atomic-Scale Understanding of Electrified Interfacial Structures and Dynamics during the Oxygen Reduction Reaction on the Fe–N4/C Electrocatalyst

Contact Info

Product

Resources

About

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Probing the Local Environment of Active Sites during 2-Propanol Oxidation to Acetone on the Co₃O₄ (001) Surface: Insights from First-Principles O K-Edge XANES Spectroscopy

Atomic-Scale Understanding of Electrified Interfacial Structures and Dynamics during the Oxygen Reduction Reaction on the Fe–N₄/C Electrocatalyst