A theoretical study of water adsorption and dissociation on Ni(111) surface during oxidative steam reforming and water gas shift processes

Wang, Wenju; Wang, Guoping

doi:10.1016/j.joei.2014.07.004

Cited by 17 publications

(4 citation statements)

References 52 publications

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“…The O-H bond length of 0.98 Å and the =HOH bond angle of 105.4˝, as listed in Table 2, are almost identical to those of a free H 2 O molecule (0.98 Å and 104.4˝, respectively). Similar adsorption behaviors of H 2 O on Ni(111) [53][54][55], Ni(100) [55], Ni(110) [55], Cu(111) [56], Cu(100) [57] and Cu(110) [58,59] were observed.…”

Section: Adsorption Of H 2 O Oh O and H On The Clean Fe(100) Surfacesupporting

confidence: 61%

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

Wang

Shao

2016

Catalysts

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Abstract:The O-H bond breaking in H 2 O molecules on metal surfaces covered with pre-adsorbed oxygen atoms is an important topic in heterogeneous catalysis. The adsorption configurations of H 2 O and relevant dissociation species on clean and O-pre-adsorbed Fe(100) surfaces were investigated by density functional theory (DFT). The preferential sites for H 2 O, HO, O, and H were investigated on both surfaces. Both the first H abstraction from adsorbed H 2 O and the subsequent OH dissociation are exothermic on the O-pre-adsorbed Fe(100) surface. However, the pre-adsorbed O significantly reduces the kinetics energy barriers for both reactions. Our results confirmed that the presence of pre-adsorbed oxygen species could significantly promote H 2 O dissociation.

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Section: Adsorption Of H 2 O Oh O and H On The Clean Fe(100) Surfacesupporting

confidence: 61%

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

Wang

Shao

2016

Catalysts

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“…The interaction of a water molecule on the clean Ni(111) surface has been theoretically studied several times. − In all works, a water molecule was found to adsorb on top of a Ni surface atom through an O–Ni bond, while “OH” and “H” are energetically more stable in hollow sites. The reported water adsorption energy E ads varied considerably from −0.03 to −0.52 eV, depending mostly on the unit cell size (typically using 2 × 2, 3 × 3, or 4 × 4 cells), the functional used, the inclusion or not of VDW corrections, and the Ni slab’s thickness (always between 3 and 4 Ni layers).…”

Section: Computational Resultsmentioning

confidence: 99%

MoS₂ Effect on Nickel Electrochemical Activation: An Atomistic/Experimental Approach

et al. 2021

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Hybrid Ni–MoS2 electrocatalysts are one of the most promising materials for the generation of hydrogen in an alkaline medium. This paper presents a simple and economical method for the rational synthesis of Ni–MoS2 nanocomposites, maximizing the contact area and reducing the contact resistance between MoS2 and the nickel surface. In this way, it is possible to maximize the synergistic effect between both materials, obtaining a hybrid nanomaterial with high electroactivity toward the generation of hydrogen. A conventional nickel catalyst (NWts) was compared with the one obtained by dispersing a small amount of MoS2 (0.1425 μg cm–2) over the surface denoted as NMS, and with the same type of catalyst after a 10 s electrodeposition of Ni (NMSN), to have a Ni–MoS2–Ni laminar structure. Thus, the NMSN catalyst shows a current density value of 59% higher than the observed value on the NMS catalyst and 113% higher than that found in the conventional NWts catalyst. Finally, these results were analyzed using DFT theoretical studies. DFT calculations predict a charge transfer between MoS2 and nearby Ni atoms, which becomes more important when a second Ni layer is placed on MoS2 explaining the increase in catalytic activity in the NMSN catalyst. Furthermore, the high hydrophobicity of the MoS2 plays an important role in the electrochemically active surface when comparing NMS and NMSN catalysts.

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“…Corresponding optimized configurations were depicted in Figure 8A‐E. All energetical and structural parameters were summarized in Table 3.Wang et al 84 theoretically investigated adsorption of H 2 O on the top, bridge, and hollow (fcc and hcp) sites of the Ni(111) surface. Adsorption of water O on top the Ni atom is found to be more favorable.…”

Section: Resultsmentioning

confidence: 99%

“…Among many adsorption configurations, we reported here only model-a where H 2 O was adsorbed on the Ag atom, model-b where H 2 O was adsorbed on the surface Ni atom, model-c where H 2 O was at the bridge position between Ag and Ni, and one H atom was pointing toward the Ag atom, model-d and model-e where H 2 O was at the bridge position between Ag and Ni, and O was pointing toward the Ag atom. Corresponding optimized configurations were depicted in Figure 8A-E. All energetical and structural parameters were summarized in Table 3.Wang et al 84 Selected optimized adsorption configurations of the proton on the Ni/Ag surface were indicated by model-f where proton was at the fcc site of the surface and being closer to the Ag atom, model-g where proton was at the hcp site of the surface and farther from the Ag atom, model-h where proton was at the fcc site of the surface and Ag atom changes its position to the hcp site, and model-i where proton was on top of the Ni atom and Ag changes its position to the bridge site of the surface, see Figure 8F-I. As energetical parameters summarized in Table 3 suggested, proton always prefers to interact directly with the Ni(111) surface instead of adsorbing on the Ag atom.…”

Section: Theoretical Analysismentioning

confidence: 99%

Experimental and theoretical study on hydrogen production by using Ag nanoparticle‐decorated graphite/Ni cathode

et al. 2020

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Summary In this study, graphite (G) electrode was coated with nickel and decorated with silver nanoparticles (G/Ni/Ag) with the help of galvanostatic method, and electrodes were used as a cathode in alkaline water electrolysis system. The characterization was achieved using X‐ray diffraction and field emission scanning electron microscopy. Hydrogen evolution performance of electrodes was investigated via cyclic voltammetry, chronoamperometry, cathodic polarization curves, and electrochemical impedance measurements. Electrochemical results showed that hydrogen production efficiency significantly increased and charge transfer resistance decreased via G/Ni/Ag. The electrochemical water splitting performance of G/Ni/Ag, was established in a joint experimental and computational effort. Water and proton adsorption on Ag‐decorated Ni surface were investigated using density functional theory. Electronic structure calculations identified the role of Ag adatom and Ni surface on water and proton adsorptions. From the computational studies, O in water was more reliable to adsorb at the bridge position of the Ag and Ni atoms, leading improved orbital overlap between H and Ni atoms and maximized chemical and physical interactions between the H2O molecules. Therefore, the Ag‐decorated Ni(111) surface provides preferable adsorption site for the O atom in water and direct interactions between water Hs and available surface Ni atoms promote water dissociation.

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A theoretical study of water adsorption and dissociation on Ni(111) surface during oxidative steam reforming and water gas shift processes

Cited by 17 publications

References 52 publications

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

MoS₂ Effect on Nickel Electrochemical Activation: An Atomistic/Experimental Approach

Experimental and theoretical study on hydrogen production by using Ag nanoparticle‐decorated graphite/Ni cathode

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A theoretical study of water adsorption and dissociation on Ni(111) surface during oxidative steam reforming and water gas shift processes

Cited by 17 publications

References 52 publications

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

MoS2 Effect on Nickel Electrochemical Activation: An Atomistic/Experimental Approach

Experimental and theoretical study on hydrogen production by using Ag nanoparticle‐decorated graphite/Ni cathode

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Product

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MoS₂ Effect on Nickel Electrochemical Activation: An Atomistic/Experimental Approach