Characterization of silica-supported copper catalysts by means of temperature-programmed reduction

Grift, C.J.G. van der; Mulder, Anne-Claire; Geus, J.W.

doi:10.1016/s0166-9834(00)82181-8

Cited by 111 publications

(54 citation statements)

References 16 publications

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“…The low temperature peaks of TPR due to highly dispersed CuO and/or Cu(II) species have also been observed for supported CuO. 44,45 Van der Grift et al 46 and Robertson et al 47 further supported this observation concluding that the highly dispersed copper oxide species are more easily reduced than bulk CuO. CAPS-CuO seemed to have no bulk copper oxide and was therefore reduced at very low temperatures, while com-CuO comprises both dispersed and bulk-like CuO resulting in a shift in reduction peak to higher temperatures without exhibiting true bulk behavior.…”

Section: Characterization Of Caps- Mes-and Com-cuomentioning

confidence: 77%

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

Poreddy

Engelbrekt

Riisager

2015

Catal. Sci. Technol.

138

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Section: Characterization Of Caps- Mes-and Com-cuomentioning

confidence: 77%

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

Poreddy

Engelbrekt

Riisager

2015

Catal. Sci. Technol.

138

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“…Incomplete reductions of Cu-ZnO/Al 2 O 3 at 503 K [16,17] and of Cu/SiO 2 at 500 K [28,36,37] have been reported and the reduction of CuO x phases may lead to an increase in reaction rates with time on stream. van der Grift et al [36,37] found by temperature programmed reduction (TPR) that several copper hydrosilicate phases reduced only above 600 K. Brands et al [28] found that Cu metal surface area increased, when a Cu/SiO 2 catalyst previously reduced at 600 K was re-reduced at 700 K. Clausen et al [26] reported that the morphology of Cu particles formed on SiO 2 by reduction in various synthesis gas mixtures at 493 K was insensitive to gas composition. Although Cu particle sizes were not reported, inspection of the EXAFS data presented with the paper indicates that the Cu particles on SiO 2 were similar in size to the particles on ZnO, for which dynamical behavior was clearly observed.…”

Section: Discussionmentioning

confidence: 99%

New insights into methanol synthesis catalysts from X-ray absorption spectroscopy

Meitzner¹,

Iglesia

1999

Catalysis Today

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X-ray absorption spectroscopic studies from several different groups provide a consistent structural picture of methanol synthesis catalysts. Copper metal is the principal Cu species detected in all in-situ XAS studies. A small amount of Cu(II) persisted in many samples reduced below 600 K, but it appears to be catalytically irrelevant. Cu(I) was not detected in any of the in-situ XAS studies. The Zn structure did not change in response to chemical treatments in any of the ZnO-containing methanol synthesis catalysts.We conclude that the slow approach to steady-state rate of methanol synthesis from CO/H 2 mixtures cannot result from changes in the Cu metal component of Cu/SiO 2 catalysts. By eliminating this possibility, we provide indirect evidence for the proposal that initial induction periods reflect slow changes in the surface of the SiO 2 or ZnO component in the catalysts. A bifunctional mechanism involving the formation of formate from CO on support hydroxyl groups would increase methanol synthesis rates as OH groups are formed by hydrolysis of Si-O bonds using the H 2 O formed in slow methanation side reactions. The bifunctional mechanism is not required for the synthesis of methanol from CO 2 -containing mixtures, because formate can form on Cu directly from CO 2 and H 2 .

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“…It has been reported by van der Grift et al. 30,31 After reduction, the characteristic structure of ZnO·SiO 2 still remained in Cu 2 Zn 2 Si 4 , whereas CuO was reduced. The XRD Peaks at 2 = 50.44°, and 74.10° for Cu species were more visible when calcination temperature was increasing, which clearly shows that the crystal size of Cu increased with the increasing calcination temperatures.…”

Section: Methodsmentioning

confidence: 62%

Hydrogenation of Ethyl Acetate to Ethanol over Bimetallic Cu-Zn/SiO₂Catalysts Prepared by Means of Coprecipitation

Zhu¹,

Shi²

2014

Bulletin of the Korean Chemical Society

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A series of bimetallic Cu-Zn/SiO 2 catalysts were prepared via thermal decomposition of the as-synthesized CuZn(OH) 4 (H 2 SiO 3 ) 2 ·nH 2 O hydroxides precursors. This highly dispersed Cu-solid base catalyst is extremely effective for hydrogenation of ethyl acetate to ethanol. The reduction and oxidation features of the precursors prepared by coprecipitation method and catalysts were extensively investigated by TGA, XRD, TPR and N 2 -adsorption techniques. Catalytic activity by ethyl acetate hydrogenation of reaction temperatures between 120 and 300 o C, different catalyst calcination and reduction temperatures, different Cu/Zn loadings have been examined extensively. The relation between the performance for hydrogenation of ethyl acetate and the structure of the Cu-solid base catalysts with Zn loading were discussed. The detected conversion of ethyl acetate reached 81.6% with a 93.8% selectivity of ethanol. This investigation of the Cu-Zn/SiO 2 catalyst provides a recently proposed pathway for ethyl acetate hydrogenation reaction to produce ethanol over Cusolid base catalysts.

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Characterization of silica-supported copper catalysts by means of temperature-programmed reduction

Cited by 111 publications

References 16 publications

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

New insights into methanol synthesis catalysts from X-ray absorption spectroscopy

Hydrogenation of Ethyl Acetate to Ethanol over Bimetallic Cu-Zn/SiO₂Catalysts Prepared by Means of Coprecipitation

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Characterization of silica-supported copper catalysts by means of temperature-programmed reduction

Cited by 111 publications

References 16 publications

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

New insights into methanol synthesis catalysts from X-ray absorption spectroscopy

Hydrogenation of Ethyl Acetate to Ethanol over Bimetallic Cu-Zn/SiO2Catalysts Prepared by Means of Coprecipitation

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Product

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About

Hydrogenation of Ethyl Acetate to Ethanol over Bimetallic Cu-Zn/SiO₂Catalysts Prepared by Means of Coprecipitation