CO oxidation catalyzed by gold supported on MgO: Spectroscopic identification of carbonate-like species bonded to gold during catalyst deactivation

Hao, You-Zeng; Mihaylov, Mihail; Ivanova, Elena; Hadjiivanov, Konstantin; Knözinger, Helmut; Gates, Bruce C.

doi:10.1016/j.jcat.2008.11.005

Cited by 94 publications

(76 citation statements)

References 47 publications

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“…† We emphasize that one important issue in the CO oxidation on Au clusters supported on metal oxides is the formation of carbonate species that poison the active sites. 51 However, one can see that the formation of a carbonate-like species (see the TS state in Fig. 2 Here, we note that, upon Ni-doping, the oxidized Au atom contributes signicantly to the LPDOS by the Fermi level, which promotes such a back-donation process for CO adsorption with an exothermic adsorption energy of 12.157 kJ mol À1 , see Fig.…”

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confidence: 83%

An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect

et al. 2017

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Catalysis using gold nanoparticles supported on oxides has been under extensive investigation for many important application processes. However, how to tune the charge state of a given Au species to perform a specific chemical reaction, e.g. CO oxidation, remains elusive. Here, using first-principles calculations, we show clearly that an intrinsically inert Au anion deposited on oxygen-deficient TiO 2 (110) (Au@TiO 2 (110)) can be tuned and optimized into a highly effective single atom catalyst (SAC), due to the depletion of the d-orbital by substrate doping. Particularly, Ni-and Cu-doped Au@TiO 2 complexes undergo a reconstruction driven by one of the two dissociated O atoms upon CO oxidation. The remaining O atom heals the surface oxygen vacancy and results in a stable bow-shaped surface "O-Au-O" species; thereby the highly oxidized Au single atom now exhibits magnetism and dramatically enhanced activity and stability for O 2 activation and CO oxidation, due to the emergence of high density of states near the Fermi level. Based on further extensive calculations, we establish the "charge selection rule" for O 2 activation and CO oxidation on Au: the positively charged Au SAC is more active than its negatively charged counterpart for O 2 activation, and the more positively charged the Au, the more active it is.

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confidence: 83%

An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect

et al. 2017

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“…However, Frondelius et al [143] observed Au(I) oxide under ambient conditions at the perimeters of the flat gold nanoclusters on an ultrathin MgO film. Gates et al did a series of work on the active state of gold supported on MgO, and they proposed the catalytic activity mainly originated from the positively charged gold [144,145]. Even when all of the gold was reduced during pretreatment under He at 200…”

Section: Active Sites Of the Au/iros For Co Oxidationmentioning

confidence: 99%

“…• C, it could be oxidized to Au ␦+ during CO oxidation reaction [144]. According to the DFT calculation of Li et al [146], the direction for electron transfer between gold and MgO depended on the planes of MgO where gold was positioned.…”

Section: Active Sites Of the Au/iros For Co Oxidationmentioning

confidence: 99%

Catalysis by gold: New insights into the support effect

et al. 2013

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“…For model catalytic studies using metal oxide supported precious metals, the concept of strong metal support interaction (SMSI) was proposed and has been well documented since the late 1970s. 44 ' 45 The SMSI effect was also reported for Au catalysts supported by TiO2, 46 where the wetting of the TiO2 surface by Au at 800 K in a reducing environment and the de-wetting of the support and the sintering of the Au in an oxidation environment were observed. 26 The surface defect sites on the support were shown to contribute significantly to the interaction between Au nanoparticles and the support.…”

Section: Adsorption Diffusion and Desorption Properties Of Tio2mentioning

confidence: 78%

“…46 The NEB method was used to follow the path between the reactant and product states to the point where the perpendicular forces on all of the images along the band were lower than 0.1 eV/A. The dimer method was subsequently used to isolate the transition state to the point where the force acting on the transition state dimer was lower than 0.03 eV/ A.…”

Section: Model System and Computation Detailsmentioning

confidence: 99%

Surface Chemistry on Oxide-Supported Au Nanoparticle Catalysts and High Surface Area Oxide Supports

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Catalytic reactions are of central importance to today's industrial development and productivity, especially when a metal that is normally unreactive becomes active. Gold nanoparticles supported on TiO2 powder have been found to be an outstanding catalyst for various reactions, while neither the TiO2 powder nor the Au nanoparticles by themselves have shown such property. The catalytic activity of a Au/TiO2 catalyst in oxidation reactions was studied using transmission infrared (IR) spectroscopy in this project. Combining high vacuum-cryogenic temperature experimental techniques and density functional theory (DFT) calculations, a special kind of Au-Ti 4 + dual perimeter site located at the interface of Au and TiO2 was identified as the key active site for oxygen activation. We demonstrated the working mechanism of this special site via three different reactions with O2 gas: CO oxidation, H2 oxidation, and acetic acid partial oxidation. Spectroscopic evidence unambiguously identified the active reaction zone at the Au-Ti 4 + dual perimeter sites.In addition, the surface properties of high area metal oxide supports were investigated. The adsorption, diffusion, and desorption of pyridine molecules on powdered nano-crystalline TiO2 and MgO was studied, demonstrating the utility of transmission IR spectroscopy in monitoring such processes. Nano-particle surface crystalline structure, surface acidity, and surface defect sites were found to play important roles in controlling adsorbate diffusivity. The influence of humidity (H2O) on the surface diffusion/desorption behavior of pyridine was also studied, where a dramatic increase in pyridine surface diffusivity over MgO was observed when modified by H2O adsorption to produce Brensted acid sites from Lewis acid sites. A weakly bound IRactive molecular O2 species was detected on the TiO2 surface at low temperatures, and its heat of adsorption was measured to be between -16 and -21 kJ mol -1 . It is suspected to be the precursor to "active" O2 species in various oxidation reactions on the catalyst surface.

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CO oxidation catalyzed by gold supported on MgO: Spectroscopic identification of carbonate-like species bonded to gold during catalyst deactivation

Cited by 94 publications

References 47 publications

An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect

An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect

Catalysis by gold: New insights into the support effect

Surface Chemistry on Oxide-Supported Au Nanoparticle Catalysts and High Surface Area Oxide Supports

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CO oxidation catalyzed by gold supported on MgO: Spectroscopic identification of carbonate-like species bonded to gold during catalyst deactivation

Cited by 94 publications

References 47 publications

An oxidized magnetic Au single atom on doped TiO2(110) becomes a high performance CO oxidation catalyst due to the charge effect

An oxidized magnetic Au single atom on doped TiO2(110) becomes a high performance CO oxidation catalyst due to the charge effect

Catalysis by gold: New insights into the support effect

Surface Chemistry on Oxide-Supported Au Nanoparticle Catalysts and High Surface Area Oxide Supports

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Product

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An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect

An oxidized magnetic Au single atom on doped TiO₂(110) becomes a high performance CO oxidation catalyst due to the charge effect