Multiscale Modeling Reveals Poisoning Mechanisms of MgO-Supported Au Clusters in CO Oxidation

Stamatakis, Michail; Christiansen, Matthew A.; Vlachos, Dionisios G.; Mpourmpakis, Giannis

doi:10.1021/nl301318b

Cited by 55 publications

(87 citation statements)

References 54 publications

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“…For a general overview of KMC approaches and applications in heterogeneous catalysis the reader is referred to Ref. 55. Here, we will briefly review the framework and present in detail the calculation of the energetics which is the focus of the present work.…”

Section: Methodsmentioning

confidence: 99%

Parallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions

Nielsen

d’Avezac

Hetherington

et al. 2013

The Journal of Chemical Physics

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143

279

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Section: Methodsmentioning

confidence: 99%

Parallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions

Nielsen

d’Avezac

Hetherington

et al. 2013

The Journal of Chemical Physics

Self Cite

143

279

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show abstract

“…22 The accumulation or depletion of electron density at a metal active sitethe atomic chargecan significantly alter adsorbate binding strength and, as a result, reactivity. 21,44 To analyze the effects of catalyst−support interactions on charge transfer, we used Bader charge analysis. 45,46 Here, we are interested in trends and not specific values of the charges, which can be very different, depending on the method used to The Journal of Physical Chemistry C Article estimate charges.…”

Section: ■ Introductionmentioning

confidence: 99%

Effect of Support Preparation and Nanoparticle Size on Catalyst–Support Interactions between Pt and Amorphous Silica

et al. 2015

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The interaction between catalytic nanoparticles (NPs) and their supports, which are often amorphous oxides, has not been well characterized at the atomic level, although it is known that, in some cases, NP−support interactions dominate the catalytic activity of the system. Furthermore, there is a lack of understanding of how support preparation affects both the stability of the NP (resistance to sintering) and the catalytic activity. We present first-principles density functional theory (DFT) calculations on amorphous silica supported Pt NPs of various sizes. Our calculations predict that support preparation methods that lead to higher hydroxyl density when NPs are deposited on the support will lead to higher resistance to sintering. We find that the total charge on supported NPs, which can affect catalyst activity, depends linearly on the number of Pt−silica bonds formed during NP deposition. The number of bonds between an NP of a known geometry and the silica support with a known hydroxyl density can be estimated from very fast discrete element method simulations, enabling the prediction of both the net charge and the adhesion energy of the particle from a linear fit correlation derived from DFT calculations of a series of differently sized Pt clusters. This work quantifies interactions between Pt NPs and amorphous silica supports and demonstrates a new method for rapid estimation of NP−support interactions on amorphous supports. ■ INTRODUCTIONRecent developments in both computational methods 1−11 and experimental characterization techniques 12−14 have facilitated detailed characterization of catalytic materials at the atomic level. Insights relating structural and electronic properties to catalytic reactivity, selectivity, and stability have provided some general rules for tailoring catalyst properties via what is now ubiquitously termed "rational design." 7−11,14,15 Many computational results have been shown to agree quite well with experimental observations, in particular, correlations involving simple properties (e.g., coordination number and adsorbate binding energies) and simple systems (e.g., extended metal surfaces and diatomic reactants). Catalytic materials research, however, has recently shifted toward ever-smaller nanoparticles (NPs) and increasingly complex support materials. Whereas approaches to understanding simple catalytic materials have been well-established and researched in recent years, 7−11,14−16 atomistic studies of supported NP systems have been limited to idealized, perfectly crystalline supports. 17−21 Numerous studies have exploited geometry-constrained calculations to isolate the effects of coordination number and NP size. 7,8,11 This approach often provides clear trends and powerful insight regarding catalyst design. However, distortion of the support structure has been shown to significantly alter the structure and electronic properties of supported NPs. 17,22 Amorphous supports exhibit a diverse range of local surface structures, which result in a distribution of catalyst−support...

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“…17,24 One of the simplest and the most studied catalytic reaction on gold clusters is a low-temperature CO oxidation by molecular oxygen. 1,2,10,12,17,[24][25][26][27][28][29][30][31] It has been demonstrated that dispersed gold supported on Co 3 O 4 , NiO, TiO 2 , and Fe 2 O 3 possesses high catalytic activity for CO oxidation. [32][33][34][35] These supports affect dramatically the catalytic activity of gold clusters.…”

Section: Introductionmentioning

confidence: 99%

CO oxidation on h-BN supported Au atom

Gao

Lyalin

Taketsugu

2013

The Journal of Chemical Physics

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The mechanism of CO oxidation by O 2 on Au atoms supported on the pristine and defected hexagonal boron nitride (h-BN) surface has been studied theoretically using density functional theory. It is found that O 2 binds stronger than CO on an Au atom supported on the defect free h-BN surface and h-BN surface with nitrogen vacancy (V N @h-BN), but weaker than CO on a free Au atom or Au trapped by a boron vacancy (V B @h-BN). The excess of the positive or negative charge on Au can considerably change its catalytic properties and enhance activation of the adsorbed O 2 . Coadsorption of CO and O 2 on Au, Au/V N @h-BN, and Au/V B @h-BN results in additional charge transfer to O 2 . Various pathways of the CO oxidation reaction by molecular oxygen are studied. We found two different pathways for CO oxidation: a two-step pathway where two CO 2 molecules are formed independently, and a self-promotion pathway where oxidation of the first CO molecule is promoted by the second CO molecule. Interaction of Au with the defect-free and defected h-BN surface considerably affects the CO oxidation reaction pathways and barriers. Therefore, Au supported on the h-BN surface (pristine or defected) cannot be considered as pseudo-free atom and support effects have to be taken into account, even when the interaction of Au with the support is weak.

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Multiscale Modeling Reveals Poisoning Mechanisms of MgO-Supported Au Clusters in CO Oxidation

Cited by 55 publications

References 54 publications

Parallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions

Parallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions

Effect of Support Preparation and Nanoparticle Size on Catalyst–Support Interactions between Pt and Amorphous Silica

CO oxidation on h-BN supported Au atom

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