First principles analysis of hydrogen chemisorption on Pd–Re alloyed overlayers and alloyed surfaces

Pallassana, Venkataraman; Neurock, Matthew; Hansen, Lars Henrik; Nørskov, Jens K.

doi:10.1063/1.481119

Cited by 76 publications

(96 citation statements)

References 38 publications

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“…[23] This correlates well with the corresponding binding energies given in Figure 3. The linear relationships show that the further the d-band center is from the Fermi level, the weaker the bond between the adsorbates and the substrate, reflecting the correctness and transportability of the d-band center model.…”

Section: H 2 O Adsorption and Dissociation On Mono-and Bimetallic Sursupporting

confidence: 86%

Do Ni/Cu and Cu/Ni Alloys have Different Catalytic Performances towards Water‐Gas Shift? A Density Functional Theory Investigation

et al. 2014

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Density functional calculations were preformed to investigate whether adding Ni into a Cu surface (denoted as Cu/Ni) or adding Cu into a Ni surface (Ni/Cu) is more efficient for catalyzing the water-gas shift (WGS)? The reactions of water dissociation and monoxide dissociation were selected to assess the activity and selectivity towards WGS, respectively. Our results show that Ni-atom modification of surfaces is thermodynamically favorable for both reactions. Kinetically, compared with pure Cu, water dissociation is greatly facilitated on Ni-modified surfaces, and the activity is insensitive to the Ni concentration; however, monoxide dissociation is not well-promoted on one Ni-atom-modified surfaces, but two Ni-atom modification can notably decrease the dissociation barriers. Overall, on the basis of these results, we conclude that 1) the catalytic performance of bimetallic metals is superior to monometallic ones; 2) at the same Ni concentration on the surface, Cu/Ni and Ni/Cu alloys have almost the same performance towards WGS; and 3) to acquire high WGS performance, the surface Ni atoms should either be low in concentration or highly dispersed.

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Section: H 2 O Adsorption and Dissociation On Mono-and Bimetallic Sursupporting

confidence: 86%

Do Ni/Cu and Cu/Ni Alloys have Different Catalytic Performances towards Water‐Gas Shift? A Density Functional Theory Investigation

et al. 2014

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“…The physical principle underlying equation (1) is simply that the importance of different surface metal atoms in determining the interaction energy with an adsorbate is given by the strength of the coupling (measured by the square of the coupling matrix element [23]) between the adsorbate and the metal d-states; a derivation of this equation is given in the Appendix. We note that heuristic versions of this expression have been used in previous work [15,24].…”

Section: Resultsmentioning

confidence: 99%

Understanding the Effect of Steps, Strain, Poisons, and Alloying: Methane Activation on Ni Surfaces

2005

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It is shown that a single parameter characterizing the electronic structure of a transition metal surface, the d-band center (e d ), can be used to provide a unified description of a range of phenomena in heterogeneous catalysis. Using methane activation on Ni surfaces as an example, we show that variations in e d can be used to quantitatively describe variations in the activation energy when the surface structure is changed, when the coverage of carbon is changed, when the surface is strained, when the surface is alloyed, and when the surface is poisoned by sulfur. The d-band center is, therefore, a very general descriptor of the reactivity of a surface.

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“…This concept was first introduced in the analysis of hydrogen chemisorption on Pd−Re alloyed overlayers and surfaces. 59 The weighted d-band center for a given surface can be calculated from eq 3 To summarize, alloying Ru with the V(110) surface apparently destabilizes the adsorption of the nitrogen atom on the surface and in the first subsurface layer. By introducing different metals to the surface, the electronic property, i.e., the d-band center of the surface, is modified, thereby affecting the reactivity of the surface.…”

Section: Atomic Nitrogen Diffusion Into Subsurface Layer Of V(110)mentioning

confidence: 99%

Nitrogen Adsorption, Dissociation, and Subsurface Diffusion on the Vanadium (110) Surface: A DFT Study for the Nitrogen-Selective Catalytic Membrane Application

2014

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Catalytic nitrogen (N 2 )-selective membrane technology with potential applications of indirect CO 2 capture and ammonia synthesis is introduced. Metallic membranes made from Earth-abundant group V metals, i.e., vanadium (V), and alloys with ruthenium (Ru) are considered. Similar to a traditional palladium (Pd)-based hydrogen (H 2 )-selective membrane for hydrogen purification, N 2 molecules preferentially adsorb on the catalytic membrane and dissociate into two nitrogen atoms. Atomic nitrogen subsequently diffuses through the crystal lattice by hopping through the interstitial crystal sites of the bulk metal, ultimately leading to atomic nitrogen on the permeate side of the membrane. This study is focused on the nitrogen interactions only at the membrane surface and the first subsurface layer. The adsorption energies of molecular as well as atomic nitrogen on the vanadium surface (V(110)) and Ru-alloyed V surface (V x Ru 100−x /V(110), where x is the atomic composition of vanadium in the alloy) are calculated using first-principles and compared against traditional catalysts for ammonia synthesis, i.e., iron (Fe). The N 2 dissociation pathway and its corresponding activation barrier are also determined. Additionally, the diffusion of atomic nitrogen from the V(110) surface to its subsurface layers is investigated to determine the rate-limiting step of nitrogen transportation across membrane surface. It has been found that N 2 and atomic nitrogen bind on the V(110) surface very strongly compared to adsorption on corresponding Fe surfaces. Although the activation energy (ca. 0.4 eV) for nitrogen dissociation on the V(110) surface is greater than that of the Fe surfaces, it is comparable to that of the Ru surfaces. Atomic nitrogen slightly prefers to stay on the V(110) surface rather than in the subsurface layers. Coupling this with the relatively high activation barrier for subsurface diffusion (ca. 1.4 eV), it is likely that the subsurface diffusion of nitrogen is the rate-limiting step of nitrogen transport across a membrane. Alloying Ru with V reduces the adsorption energy of atomic nitrogen on the Ru-alloyed V(110) surface in addition to the subsurface layer. Therefore, it is expected to facilitate nitrogen transport across the membrane surface.

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First principles analysis of hydrogen chemisorption on Pd–Re alloyed overlayers and alloyed surfaces

Cited by 76 publications

References 38 publications

Do Ni/Cu and Cu/Ni Alloys have Different Catalytic Performances towards Water‐Gas Shift? A Density Functional Theory Investigation

Do Ni/Cu and Cu/Ni Alloys have Different Catalytic Performances towards Water‐Gas Shift? A Density Functional Theory Investigation

Understanding the Effect of Steps, Strain, Poisons, and Alloying: Methane Activation on Ni Surfaces

Nitrogen Adsorption, Dissociation, and Subsurface Diffusion on the Vanadium (110) Surface: A DFT Study for the Nitrogen-Selective Catalytic Membrane Application

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