Role of gold cations in the oxidation of carbon monoxide catalyzed by iron oxide-supported gold

Hutchings, Graham J.; Hall, Matthew S.; Carley, Albert Frederick; Landon, Philip; Solsona, Benjamín; Kiely, Christopher J.; Herzing, Andrew A.; Makkee, Michiel; Moulijn, Jacob A.; Overweg, A.R.; Fierro-Gonzalez, Juan C.; Guzmán, Javier; Gates, Bruce C.

doi:10.1016/j.jcat.2006.06.001

Cited by 321 publications

(242 citation statements)

References 43 publications

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“…The hypothesis was that very finely dispersed gold created a large number of interfacial gold ions, which along with the metallic gold sites contributed to activity. In a more recent examination of this type catalyst, Hutchings et al [29] have claimed that gold cations are key for an active catalyst. However, their samples always contained a mixture of both gold nanoparticles and gold ions.…”

Section: Co Oxidation On Au/fe 2 Omentioning

confidence: 99%

“…There is conflicting information in the literature about the oxidation state of gold during the dry CO oxidation reaction [4,11,14,15,[25][26][27][28][29][30][31][32][33]. There is also an unresolved issue of the importance of gold particle size for this reaction [5,34,35], while a recent theoretical study finds no effect of the type of oxide support if gold clusters with a large number of cus sites are used [36].…”

Section: Introductionmentioning

confidence: 99%

“…The coordination of gold to supports is tunable by the reacting mixture composition [31]. Most of the catalysts incorporating Au(0) also contain cationic gold [26,29,[42][43][44][45] and it is very difficult to separate the function of each. In this paper, we report new data on the catalytic activity and structure of nanoscale Au/ Fe 2 O 3 and Au/CeO 2 in low-temperature CO oxidation and the WGS reactions.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of the activity of Au/CeO2 and Au/Fe2O3 catalysts for the CO oxidation and the water-gas shift reactions

et al. 2007

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We compare the activity and relevant gold species of nanostructured gold-cerium oxide and gold-iron oxide catalysts for the CO oxidation by dioxygen and water. Well dispersed gold nanoparticles in reduced form provide the active sites for the CO oxidation reaction on both oxide supports. On the other hand, oxidized gold species, strongly bound on the support catalyze the water-gas shift reaction. Gold species weakly bound to ceria (doped with lanthana) or iron oxide can be removed by sodium cyanide at pH ‡12. Both parent and leached catalysts were investigated. The activity of the leached gold-iron oxide catalyst in CO oxidation is approximately two orders of magnitude lower than that of the parent material. However, after exposure to H 2 up to 400°C gold diffuses out and is in reduced form on the surface, a process accompanied by a dramatic enhancement of the CO oxidation activity. Similar results were found with the gold-ceria catalysts. On the other hand, pre-reduction of the calcined leached catalyst samples did not promote their water-gas shift activity. UV-Vis, XANES and XPS were used to probe the oxidation state of the catalysts after various treatments.

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Section: Co Oxidation On Au/fe 2 Omentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparison of the activity of Au/CeO2 and Au/Fe2O3 catalysts for the CO oxidation and the water-gas shift reactions

et al. 2007

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“…[2][3][4][5][6][7][8][9][10] The catalytic properties of gold are strongly size-dependent and emerge when the size of particles decreases to 1-5 nm, whereas larger particles and the bulk form of gold are catalytically inert. 1,2,5 The enormous interest in gold nanocatalysis is stipulated by the fact that gold nanoparticles are active and selective even at room temperatures that makes them unique catalysts for many industrial applications.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, the positive charge accumulated on the gold can promote adsorption of CO and hydrocarbons. 7,50 It has been demonstrated that the CO oxidation reaction catalyzed by gold clusters can occur via Langmuir-Hinshelwood (LH) or Eley-Rideal (ER) mechanisms, depending on the cluster charge. Thus the neutral Au 10 can catalyze oxidation of CO via the LangmuirHinshelwood mechanism even below room temperature.…”

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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Recent Developments in Gold Nanomaterial Catalysts for Oxidation Reaction through Green and Sustainable Routes

Chowdhury¹,

Santra²,

Mandal³

et al. 2014

Advanced Materials for Agriculture, Food, and Environmental Safety

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Role of gold cations in the oxidation of carbon monoxide catalyzed by iron oxide-supported gold

Cited by 321 publications

References 43 publications

Comparison of the activity of Au/CeO2 and Au/Fe2O3 catalysts for the CO oxidation and the water-gas shift reactions

Comparison of the activity of Au/CeO2 and Au/Fe2O3 catalysts for the CO oxidation and the water-gas shift reactions

CO oxidation on h-BN supported Au atom

Recent Developments in Gold Nanomaterial Catalysts for Oxidation Reaction through Green and Sustainable Routes

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