A DFT study of H 2 O dissociation on metal‐precovered Fe (100) surface

et al. 2021

Mat. Res.

The O 2 adsorption and dissociation on M-doped (M=Al, Ag, W) Cu ( 111) surface were studied by density functional theory. The adsorption energy of adsorbate, the average binding energy and surface energy of Cu surface, and the doping energy of doping atom were calculated. All the doped atoms can be stably combined with Cu atoms and improve the surface activity of Cu surface, while the Al and W atoms would strengthen the bonding effect between the atoms on the Cu (111) slab except Ag doping atom. Due to the different electronegativity of three metals of Al, Ag, W, these doping atoms can resist the dissociation of O 2 by DOS analysis. The potential energy surface was computed, and the result showed that the dissociation reaction of O 2 on the surfaces not only reflected in the barrier energy, but also the reaction energy. Ag atoms had the best resistance effect on the O 2 dissociation comparing with Al and W atoms because of the large barrier energy and reaction energy.

Section: O 2 Dissociation On Pristine/doped Cu (111) Surfacesupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Study of the M-doped Effect (M=Al, Ag, W) on the Dissociation of O2 on Cu Surface Using a First Principles Method

Qiao

Xu²,

et al. 2021

Mat. Res.

“…In order to fundamentally understand the process of FTS reaction, it is essential to investigate the mechanism of CO activation hydrogenation on the surface of Fe- and Co-based catalysts, and several pathways for CO activation have been proposed, including direct CO dissociation, hydrogenation, and insertion into the growth chain for activation [ 33 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. It is generally accepted that CO dissociation is the rate-determining step [ 42 , 46 ].…”

Section: H 2 O Derivatives Mediate Co Activationmentioning

confidence: 99%

“…There are two parallel CO activation pathways on the surface of Fe and Co-based catalysts, which are unassisted activation and H-assisted activation [ 39 , 40 , 41 , 42 , 43 , 44 , 66 ]. Reaction paths and products vary under different reaction conditions.…”

Section: H 2 O Derivatives Mediate Co Activationmentioning

confidence: 99%

H2O Derivatives Mediate CO Activation in Fischer–Tropsch Synthesis: A Review

Wang

et al. 2023

Molecules

The process of Fischer–Tropsch synthesis is commonly described as a series of reactions in which CO and H2 are dissociated and adsorbed on the metals and then rearranged to produce hydrocarbons and H2O. However, CO dissociation adsorption is regarded as the initial stage of Fischer–Tropsch synthesis and an essential factor in the control of catalytic activity. Several pathways have been proposed to activate CO, namely direct CO dissociation, activation hydrogenation, and activation by insertion into growing chains. In addition, H2O is considered an important by-product of Fischer–Tropsch synthesis reactions and has been shown to play a key role in regulating the distribution of Fischer–Tropsch synthesis products. The presence of H2O may influence the reaction rate, the product distribution, and the deactivation rate. Focus on H2O molecules and H2O-derivatives (H*, OH* and O*) can assist CO activation hydrogenation on Fe- and Co-based catalysts. In this work, the intermediates (C*, O*, HCO*, COH*, COH*, CH*, etc.) and reaction pathways were analyzed, and the H2O and H2O derivatives (H*, OH* and O*) on Fe- and Co-based catalysts and their role in the Fischer–Tropsch synthesis reaction process were reviewed.

“…The structure determines the property, and the surface structure affects the process of surface adsorption and dissociation. The vacancy, substitution, doping, and defect are all typical types of surface structure, in which the surface‐doped elements are an important dissociated affecting factor because they could penetrate the substrate actively, change the surface activity, and affect the binding of adsorbate on the surface 11–13 . From this point of view, it can be considered that the dissociation of O 2 can be steered by the surface structure 14 .…”

Section: Introductionmentioning

confidence: 99%

O₂ dissociative adsorption on the Cu‐, Ag‐, and W‐doped Al(111) surfaces from DFT computation

Qiao

Surface & Interface Analysis

et al. 2020

The O2 adsorption and dissociation on M‐doped (M = Cu, Ag, W) Al(111) surface were studied by density functional theory. The adsorption energy of adsorbate, the average binding energy and surface energy of Al surface, and the doping energy of doping atom were calculated. All the doped atoms can be stably combined with Al atoms, while being slightly embedded in the surface to a certain depth. The TOP‐type surfaces are the most stable doped surfaces for O2 adsorption, which is related to the orbital hybridization between the adsorbate and the surface atoms, the electronegativity, and the orbital energy level of the doping atoms. Moreover, the O atoms and doping atoms contribute significantly to the density of states (DOS), especially the O‐p orbital electrons and the d orbital electrons of doping atoms. The degree of O2 dissociation is related to the doping atoms on Al surfaces, and the doping atoms actually resist the dissociation of O2. W atoms have the best resistance effect on the O2 dissociation as compared with Cu and Ag atoms, especially W‐1NN surface, which has both large barrier energy and reaction energy.