H2 dissociation on γ-Al2O3 supported Cu/Pd atoms: A DFT investigation

Wang, Hongtao; Chen, Lijuan; Lv, Yongkang; Ren, Rui-Peng

doi:10.1016/j.apsusc.2013.11.019

Cited by 26 publications

(9 citation statements)

References 53 publications

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“…The γ‐Al 2 O 3 (1 1 0) surface was cleaved from Digne's γ‐Al 2 O 3 model to make a three‐layer slab with a (2×2) unit cell, where the top layer was relaxed and the bottom two layers were fixed in their bulk position. The calculated lattice parameters for bulk γ‐Al 2 O 3 were a =5.577 Å, b / a =1.506, c / a =1.447, α = γ =90°, and β =90.54°, and in good agreement with the previous works of Digne and Wang et al . All slabs were separated with a vacuum of 14 Å along the normal direction to the surface.…”

Section: Methodssupporting

confidence: 89%

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

et al. 2017

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Rapid computational screening to aid novel catalyst design has evolved into an important and ubiquitous tool in modern heterogeneous catalysis. A possible shortcoming of this approach, however, is the material gap, that is, simplified computational models used for catalyst screening do not always capture the complexity of real catalytic systems. Here we investigate the importance of the material gap for complete methane oxidation over supported Pd/γ‐Al2O3 catalysts using a combination of DFT simulations and temperature‐programmed oxidation experiments. The Pd/γ‐Al2O3 active site was approximated by four models of increasing complexity, namely Pd(1 0 0), Pd(2 1 1), PdO(1 0 1), and Pd10/γ‐Al2O3(1 1 0), and each was also modified with metal promoters to discover reactivity trends. Although the unpromoted Pd model surfaces exhibit different methane activation activities, our DFT results indicate that an experimentally verified performance trend can be predicted for their promoted counterparts irrespective of the active‐site representation. We attribute the robustness of the trend predictions in this particular system to localized changes in the electron density during methane activation. Overall, our work supports the commonly practiced active‐site model simplifications during computational catalyst screening and provides fundamental insight into the qualitative agreement between theory and experiment for methane oxidation over promoted Pd catalysts.

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Section: Methodssupporting

confidence: 89%

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

et al. 2017

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“…Each slab consists of an equivalent of four layers in which the top two were allowed to relax and the bottom two were fixed to their bulk positions. The calculated lattice parameters for bulk g-Al 2 O 3 were a = 5.577 , b/a = 1.506, c/a = 1.447, a = g = 908,a nd b = 90.548,a nd in good agreement with the previous works of Digne [41] and Wang et al [42] All slabs were separated with av acuum of 14 along the normal direction to the surface. [40] The calculated lattice constants are a = 3.958 for Pd and a = 3.100 and c/a = 1.755 for PdO.…”

Section: Methodssupporting

confidence: 89%

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

et al. 2017

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“…The adsorption and dissociation of the diatomic H 2 molecule on metal surfaces have always been of huge interest due to their great value in both academic and industrial fields. − The interaction of H 2 with metal surfaces has long received much theoretical and experimental attention on the basis of the enormous application potential in many fields, such as heterogeneous catalysis, chemical corrosion, and fuel cells, as well as the nuclear industry and aerospace industry, and so on, − in which a detailed description about H 2 adsorption and dissociation on metal surfaces will help better understand the activation processes of H 2 and make improvements for the applications. Therefore, it is significantly necessary to make a fundamental understanding of the adsorption and dissociation behaviors of H 2 over metal surfaces at the atomic scale; as a result, the activation of H 2 at the initial stage and its further hydrogenation will be clarified.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Study about the Effect of Coverage on H₂ Adsorption and Dissociation over a Rh(100) Surface

et al. 2015

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The adsorption and dissociation of H 2 with different coverages over the Rh(100) surface have been systematically investigated to probe into the effect of coverage on H 2 adsorption and dissociation. Here, the results are obtained using the density functional theory (DFT) method together with the periodic slab model. Both the parallel and vertical modes of H 2 adsorption on the Rh(100) surface have been identified, and the detailed studies corresponding to H 2 adsorption and dissociation at different coverages are presented. Our results show that the parallel mode of a single H 2 adsorbed on the Rh(100) surface is more favorable than the vertical mode, in which the top site is the most stable adsorption site. However, the parallel modes of single H 2 adsorbed at the bridge and 4F hollow sites, as well as the vertical mode of single H 2 adsorbed at the 4F hollow site are all the dissociative adsorption. On the other hand, with the increasing of H 2 coverage from low to high, the most stable adsorption configurations of H 2 is the parallel adsorption mode at the top site, and the adsorption energies of these adsorbed H 2 molecules will decrease gradually until the saturated adsorption with H 2 coverage of 6/12 ML, further, the dissociation of these adsorbed H 2 molecules is more favorable both kinetically and thermodynamically than their desorption, suggesting that the dissociation of the adsorbed H 2 molecule is more favored than their desorption. Finally, considering the dissociative adsorption of the single H 2 molecule with the parallel modes at the bridge and 4F hollow sites, as well as the vertical mode at the 4F hollow site, our results still show that the adsorptions of H 2 with different coverages at these sites are still the dissociative adsorption with the dissociative H atoms adsorbed on the Rh surface. Therefore, H 2 dominantly exists in the form of H atoms on Rh catalyst under realistic conditions.

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H2 dissociation on γ-Al2O3 supported Cu/Pd atoms: A DFT investigation

Cited by 26 publications

References 53 publications

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

First-Principles Study about the Effect of Coverage on H₂ Adsorption and Dissociation over a Rh(100) Surface

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H2 dissociation on γ-Al2O3 supported Cu/Pd atoms: A DFT investigation

Cited by 26 publications

References 53 publications

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

From Active‐Site Models to Real Catalysts: Importance of the Material Gap in the Design of Pd Catalysts for Methane Oxidation

First-Principles Study about the Effect of Coverage on H2 Adsorption and Dissociation over a Rh(100) Surface

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First-Principles Study about the Effect of Coverage on H₂ Adsorption and Dissociation over a Rh(100) Surface