Gold supported on surface acidity modified Y-type and iron/Y-type zeolite for CO oxidation

Lin, Jheng-Hua; Chen, Jen-Ho; Hsiao, Chih‐Yang; Kang, Yih-Ming; Wan, Ben‐Zu

doi:10.1016/s0926-3373(01)00276-4

Cited by 84 publications

(66 citation statements)

References 27 publications

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“…The peaks of the second species (88.1 and 91.6 eV) are strongly shifted with respect to metallic gold and are assigned to Au 3+ -containing species representing ∼ 21% of the total Au amount. Similar peaks (87.7-88.2 and 91.4-91.8 eV) assigned to Au 3+ -hydroxy species (Au(OH) 3 , Au(OH) 2 + ) were observed in nonreduced Au/Al 2 O 3 [31] and Au/Y-type zeolite [34] prepared by deposition/precipitation using HAuCl 4 . Au 2 O 3 cannot be responsible for these peaks since it presents signals at lower BE, 85.5-86.5 and 89.6 eV [31,34].…”

Section: Au/acf Catalysts Formationsupporting

confidence: 57%

“…Similar peaks (87.7-88.2 and 91.4-91.8 eV) assigned to Au 3+ -hydroxy species (Au(OH) 3 , Au(OH) 2 + ) were observed in nonreduced Au/Al 2 O 3 [31] and Au/Y-type zeolite [34] prepared by deposition/precipitation using HAuCl 4 . Au 2 O 3 cannot be responsible for these peaks since it presents signals at lower BE, 85.5-86.5 and 89.6 eV [31,34]. These species seems also to exist in the sample (not taken into account during the deconvolution), but with a much lower surface concentration than other species.…”

Section: Au/acf Catalysts Formationsupporting

confidence: 57%

“…The spectrum was complex; therefore, it was deconvoluted into several components. The first doublet with peaks at 84.0 and 87.7 eV is characteristic for metallic gold [31][32][33][34]. Metal Au 0 represents ∼ 43% of the total gold deposited and was assigned to the particles of 2 nm observed by HRTEM (Fig.…”

Section: Au/acf Catalysts Formationmentioning

confidence: 93%

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Highly dispersed gold on activated carbon fibers for low-temperature CO oxidation

Bulushev

Yuranov

Suvorova

et al. 2004

Journal of Catalysis

204

132

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Gold nanoparticles of 2-5 nm supported on woven fabrics of activated carbon fibers (ACF) were effective during CO oxidation at room temperature. To obtain a high metal dispersion, Au was deposited on ACF from aqueous solution of ethylenediamine complex [Au(en) 2 ]Cl 3 via ion exchange with protons of surface functional groups. The temperature-programmed decomposition method showed the presence of two main types of functional groups on the ACF surface: the first type was associated with carboxylic groups easily decomposing to CO 2 and the second one corresponded to more stable phenolic groups decomposing to CO. The concentration and the nature of surface functional groups was controlled using HNO 3 pretreatment followed by either calcination in He (300-1273 K) or by iron oxide deposition. The phenolic groups are able to attach Au 3+ ions, leading to the formation of small Au nanoparticles (< 5 nm) after reduction by H 2 . This was confirmed by high-resolution electron microscopy combined with X-ray energy-dispersive analysis. The catalyst with high Au dispersion demonstrated high activity in CO oxidation. The surface carboxylic groups decomposed during interaction with [Au(en) 2 ]Cl 3 solution and reduced Au 3+ to Au 0 , resulting in the formation of bigger (> 9 nm) Au agglomerates after reduction by H 2 . These catalysts demonstrated lower activity as compared to the ones containing mostly small Au nanoparticles. Complete removal of surface functional groups rendered an inert support that would not interact with the Au precursor. The oxidation state of gold in the Au/ACF catalysts was controlled by X-ray photoelectron spectroscopy before and after the reduction in H 2 . The high-temperature reduction in H 2 (673-773 K) was necessary to activate the catalyst, indicating that metallic gold nanoparticles are active during catalytic CO oxidation.  2004 Elsevier Inc. All rights reserved.

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Section: Au/acf Catalysts Formationsupporting

confidence: 57%

Section: Au/acf Catalysts Formationsupporting

confidence: 57%

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Highly dispersed gold on activated carbon fibers for low-temperature CO oxidation

Bulushev

Yuranov

Suvorova

et al. 2004

Journal of Catalysis

204

132

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“…However, the direct hydrogenation of propene to propane, which is observed for particles under 2 nm, is still difficult to explain in the context of such a mechanism. In addition, very few studies have been performed that address the long-term performance of these catalysts (501,503,(533)(534)(535). Some results have indicated that agglomeration of gold particles could pose a serious threat to long-term stable activity (192,394,412,421,476,535).…”

Section: Figure 29mentioning

confidence: 99%

“…In addition, very few studies have been performed that address the long-term performance of these catalysts (501,503,(533)(534)(535). Some results have indicated that agglomeration of gold particles could pose a serious threat to long-term stable activity (192,394,412,421,476,535). Others have attributed the presence (403,432,506) or absence (507,508,512,513) of water as a contributing factor to deactivation.…”

Section: Figure 29mentioning

confidence: 99%

Surface chemistry of catalysis by gold

et al. 2004

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IntroductionGold has long been regarded as an "inert" surface and bulk gold surfaces do not chemisorb many molecules easily. However, in the last decade, largely through the efforts of Masatake Haruta, gold particles, particularly those below 5 nm in size, have begun to garner attention for unique catalytic properties (1-8). In recent years, supported gold particles have been shown to be effective as catalysts for low temperature CO oxidation (9), selective oxidation of propene to propene oxide (10), water gas shift (11), NO reduction (12), selective hydrogenation of acetylene (or butadiene) (13)

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