Electronic Factors Governing Ethylene Hydrogenation and Dehydrogenation Activity of Pseudomorphic PdML/Re(0001), PdML/Ru(0001), Pd(111), and PdML/Au(111) Surfaces

Pallassana, Venkataraman; Neurock, Matthew

doi:10.1006/jcat.1999.2724

Cited by 380 publications

(314 citation statements)

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“…With the advent of Density Functional Theory (DFT) it became possible to compute the effect of defects in smooth terraces and highly active singularities such as steps on metal surfaces in promoting dissociative adsorption, AB(g) = A(ad) + B(ad) [10][11][12]. Recently the BEP correlation has found wide application in these heterogeneous dissociative-attachment reactions as a means of relating barrier height to energy release [13][14][15][16][17][18] and has also been applied to atomic diffusion on metals [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Ning

Polanyi

2013

Zeitschrift für Physikalische Chemie

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The first calculation of reaction dynamics was made in 1931 by H. Eyring and M. Polanyi for the gas-phase exchange reaction H(g) + H 2 (g) = H 2 (g) + H(g). Here we use Density Functional Theory to explore the dynamics of an analogous exchange reaction, H(ad) + H 2 (ad) = H 2 (g) + H(ad), taking place at coinage metal surfaces; Cu(100), Ag(100) and Au(100). The attacking atom, H(ad), recoils in a preferred direction toward the physisorbed H 2 (ad), as envisioned in other studies of 'Surface Aligned Reaction' (SAR). The dynamics of SAR for the above reaction is compared with gas-phase reaction, employing the same initial state geometry in the absence of the surface. The effect of weak physisorption at the metal surface is to approximately halve the bond dissociation energy of H 2 (ad) as compared with H 2 (g). As a result, the surface markedly catalyzes the exchange reaction, decreasing the energy barrier due to increased heat of reaction in the adsorbed state, in accord with the Brønsted, Evans and Polanyi (BEP) relationship.

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Section: Introductionmentioning

confidence: 99%

Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Ning

Polanyi

2013

Zeitschrift für Physikalische Chemie

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“…the Brønsted-Evans-Polanyi (BEP) relations, is able to show that the transition state energy of a reaction is linearly depending on the reaction energy. 7,8,9,10,11,12 Herein, we investigate the transition state energies of a large number of essential bond breaking and forming reactions that play a key role in the catalytic transformation of a large fraction of base chemicals. The transition state energies investigated include C-C, C-O, C-N, N-O, N-N, and O-O coupling and have been calculated on different stepped surfaces of transition metals such as Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au.…”

mentioning

confidence: 99%

Universal Brønsted-Evans-Polanyi Relations for C–C, C–O, C–N, N–O, N–N, and O–O Dissociation Reactions

Temel²,

et al. 2010

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It is shown that for all the essential bond forming and bond breaking reactions on metal surfaces, the reactivity of the metal surface correlates linearly with the reaction energy in a single universal relation. Such correlations provide an easy way of establishing trends in reactivity among the different transition metals. Keywords Density Functional Theory -Stepped surfaces -Coupling reactions -Bond breaking reactions -BEP relations -Scaling relationsTo bridge the gap between macroscopic properties of a catalyst, such as turn-over rates and selectivity and the microscopic properties obtained from electronic structure methods based on density functional theory (DFT), an in depth understanding of the underlying thermodynamics and kinetics of the corresponding metal surfaces is needed. Today, DFT has reached a level of sophistication where it can be used to describe complete catalytic reactions and hence provide an insight that pinpoints to the origin of the catalytic activity and selectivity. 1,2,3,4,5,6 However, extensive DFT calculations that eventually lead to this understanding are still computationally demanding. A simplification that connects the reactivity and selectivity of a catalytic surface to one or few descriptors is therefore extremely useful. Such a simplification, e.g. the Brønsted-Evans-Polanyi (BEP) relations, is able to show that the transition state energy of a reaction is linearly depending on the reaction energy. 7,8,9,10,11,12 * Corresponding author SLAC-PUB-14285 2 Herein, we investigate the transition state energies of a large number of essential bond breaking and forming reactions that play a key role in the catalytic transformation of a large fraction of base chemicals. The transition state energies investigated include C-C, C-O, C-N, N-O, N-N, and O-O coupling and have been calculated on different stepped surfaces of transition metals such as Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au. For a dissociation reaction (AB → A+B), the transition state energy (E ts ) is calculated by Equation (1), in which E ts/slab , E slab and E gas are the total energies of the slab with transition states, the clean slab, and the gas phase molecules relevant for the reactions, respectively. The dissociative adsorption energy (E diss ) is calculated by Equation (2), in which E A/slab and E B/slab are the total energies of the slab with adsorbates A and B, respectively.(1)All calculations were performed using the DACAPO plane-wave pseudo potential DFT code. 13 Ionic cores were described by ultrasoft pseudopotentials 14, and the Kohn-Sham one-electron valence states were expanded in a basis of plane wave functions with a cutoff energy up to 340 eV. For most adsorption systems, the surface Brillouin zone was sampled using a Monkhorst-Pack grid of size 4×4×1, while 2×3×1 was used for O 2 , and 8×6×1 was used for N 2 and NO as a test of the parameters. The self-consistent electron density was determined by iterative diagonalization of the Kohn-Sham Hamiltonian. A Fermi distribution for the population of...

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“…[9,16,19,20] Recently, a single transition state scaling relation has been identified for a large number of C-C, C-O, C-N, N-O, N-N, and O-O coupling reactions.…”

mentioning

confidence: 99%

“…[9,16,19,20] Recently, a single transition state scaling relation has been identified for a large number of C-C, C-O, C-N, N-O, N-N, and O-O coupling reactions. [21] The scaling relations provide a powerful tool for the investigation of reaction mechanisms and the prediction of potential energy surfaces.…”

mentioning

confidence: 99%

Descriptor‐Based Analysis Applied to HCN Synthesis from NH₃ and CH₄

et al. 2011

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The design of solid metal catalysts using theoretical methods has been a long-standing goal in heterogeneous catalysis. [1, 2] Recent developments in methodology and computer technology as well as the establishment of a descriptor-based approach for the analysis of reaction mechanisms and trends across the periodic table allow for the fast screening for new catalytic materials and have lead to first examples of computational discoveries of new materials. [3][4][5][6][7][8] The underlying principles of the descriptor-based approach are the existence of relations between the surface electronic structure, adsorption energies and activation barriers that result in volcanoshaped activity plots as function of simple descriptors, such as atomic binding energies or the d-band center. [1,6,[9][10][11][12][13][14][15][16][17] Linear scaling relations have been established between the adsorption energies of hydrogen-containing molecules such as CH x , NH x , OH x and SH x and the C, N O and S adsorption energies on transition-metal surfaces.[18] Transition-state energies have also beenshown to scale linearly with adsorption energies in a similar fashion. [9,16,19,20] Recently, a single transition state scaling relation has been identified for a large number of C-C, C-O, C-N, N-O, N-N, and O-O coupling reactions.[21] The scaling relations provide a powerful tool for the investigation of reaction mechanisms and the prediction of potential energy surfaces. They limit the number of independent variables to a few, typically adsorption energies of key atoms. Using this information as input to a microkinetic model provides an understanding of trends in catalytic activity across the transition metals. In most cases a volcano-shaped relation between activity and the key variables, the descriptors, is observed.[16]In the present paper we will provide an example of the approach outlined above and show how one can obtain an understanding of activity/selectivity trends of a reaction with just a few new calculations. We take the synthesis of hydrogen cyanide (HCN), a versatile synthetic building block in organic chemistry, as an example.[ The industrially used Pt/Rh gauze catalysts reach their optimal activity only after an extended activation period under reaction conditions.[23] SEM [26] and STM [27] characterization of the catalyst have shown that during this activation period the catalysts surface area is increased (roughening) and random faceting occurs. As an approximation of the active site on this surface, we use the stepped (211) facet, which has also been shown to dominate the catalytic activity in other reactions. [28] . Pt is the active catalytic component of the Pt/Rh catalyst, while the role of Rh is to increase the long term stability.[23]We consider the following elementary steps, including 9 different routes for C-N coupling between CH x and NH y with x,y = 0,1,2, where X* denotes an adsorbed species and * represents an empty surface site: CH 4 (g) + 2* → CH 3 * + H* CH 3 * + * → CH 2 * + H* CH 2 * + * → CH* + H* CH* +...

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Electronic Factors Governing Ethylene Hydrogenation and Dehydrogenation Activity of Pseudomorphic PdML/Re(0001), PdML/Ru(0001), Pd(111), and PdML/Au(111) Surfaces

Cited by 380 publications

References 70 publications

Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Universal Brønsted-Evans-Polanyi Relations for C–C, C–O, C–N, N–O, N–N, and O–O Dissociation Reactions

Descriptor‐Based Analysis Applied to HCN Synthesis from NH₃ and CH₄

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Electronic Factors Governing Ethylene Hydrogenation and Dehydrogenation Activity of Pseudomorphic PdML/Re(0001), PdML/Ru(0001), Pd(111), and PdML/Au(111) Surfaces

Cited by 380 publications

References 70 publications

Catalyzed Surface-Aligned Reaction, H(ad) + H2(ad) = H2(g) + H(ad) on Coinage Metals

Catalyzed Surface-Aligned Reaction, H(ad) + H2(ad) = H2(g) + H(ad) on Coinage Metals

Universal Brønsted-Evans-Polanyi Relations for C–C, C–O, C–N, N–O, N–N, and O–O Dissociation Reactions

Descriptor‐Based Analysis Applied to HCN Synthesis from NH3 and CH4

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Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Catalyzed Surface-Aligned Reaction, H(ad) + H₂(ad) = H₂(g) + H(ad) on Coinage Metals

Descriptor‐Based Analysis Applied to HCN Synthesis from NH₃ and CH₄