The interaction effects of dehydration function on catalytic performance and properties of hybrid catalysts upon LPDME process

Moradi, Gholamreza; Nazari, Mohadese; Yaripour, Fereydoon

doi:10.1016/j.fuproc.2008.09.014

Cited by 30 publications

(13 citation statements)

References 18 publications

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“…Since XRD data did not show appreciable changes in the average CuO particle size for the hybrid catalysts with respect to the bare CZA catalyst, as previously discussed, small variations in the reducibility of CuO species probably reflect subtle modifications in the interaction strength of this oxide with the zeolite [13,34,64]. As qualitatively appreciated in Fig.…”

Section: Properties Of Cu Species In Cza/zeolite Hybrid Catalystssupporting

confidence: 64%

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

García‐Trenco

Valencia

Martı́nez

2013

Applied Catalysis A: General

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Section: Properties Of Cu Species In Cza/zeolite Hybrid Catalystssupporting

confidence: 64%

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

García‐Trenco

Valencia

Martı́nez

2013

Applied Catalysis A: General

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“…As shown in Fig. 3, two distinctive reduction peaks were observed with the first reduction peak below temperature of 250°C (T R1 ), which can be attributed to the bulk reduction of CuO, and the second reduction peak above 250°C (T R2 ), which can be assigned to the reduction of the strongly interacted CZA particles on the strong acid sites of the mesoporous c-Al 2 O 3 by forming strong metal-support interaction [22,[26][27][28][29]. A first reduction peak can be separated into two peaks, which can be possibly attributed to the different dispersion of copper species in the CZA matrix, and the maximum reduction peak temperature was found to be lower at *185 and 240°C on CZA/Al 2 O 3 (10) compared to other hybrid catalysts, which showed first reduction temperatures at around 195-215 and 255-285°C.…”

Section: Surface Acidity and Metal-support Interaction On The Cza/al mentioning

confidence: 95%

The role of the acidity of alumina prepared by aluminum-carbon black composite for CO hydrogenation to dimethyl ether on hybrid Cu–ZnO–Al2O3/alumina

Ham

Jeong

Koo

et al. 2015

Reac Kinet Mech Cat

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The effects of surface area and the acidity of mesoporous c-Al 2 O 3 , which is prepared by calcining aluminum-carbon black composite (Al/CB) of the precipitated aluminum nitrate on carbon black at different weight ratios, were investigated to verify the roles of carbon black in the surface properties and stability of Cu-ZnO-Al 2 O 3 for the direct synthesis of dimethyl ether (DME) from syngas. A high surface area of *100 m 2 /g with a large pore diameter of *25 nm originated from the occupied spaces of carbon black enhanced the dispersion of the active Cu-ZnO-Al 2 O 3 particles by forming a strong and stable interaction with mesoporous solid acid c-Al 2 O 3 surfaces. The enhanced dispersion of copper-containing particles, being strongly interacted with the acid sites of the hybrid Cu-ZnO-Al 2 O 3 / Al 2 O 3 catalyst using c-Al 2 O 3 prepared at an optimal Al/CB weight ratio of 10, is mainly responsible for the high CO conversion with a high yield to oxygenates and a suppressed aggregation of active copper species during the direct synthesis of DME from syngas.Keywords Dimethyl ether (DME) Á Syngas Á Cu-ZnO-Al 2 O 3 Á Hybrid catalyst Á Composite of carbon black and alumina Á Acid sites Electronic supplementary material The online version of this article (

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“…7a is, in principle, valid for hybrids prepared by mixing the pellets of CZA (oxide precursor) and zeolite components in the desired proportion. However, a widely applied method for preparing the hybrids is by grinding the components in their powder form and then pelletizing the homogenous solid mixture to the wanted particle size [17,18,35]. Therefore, in order to clear up whether or not the conclusion regarding the influence of zeolite acidity on the STD behavior can be generally applied for other preparation methods, hybrids prepared by the grinding method (G-series, see section 2.1.3 of Experimental) with exactly the same composition than those obtained by mixing the pellets (M-series) were evaluated under the same experimental conditions.…”

Section: Influence Of Zeolite Acidity On Methanol Dehydration Activitymentioning

confidence: 99%

Direct synthesis of DME from syngas on hybrid CuZnAl/ZSM-5 catalysts: New insights into the role of zeolite acidity

García‐Trenco

Martı́nez

2012

Applied Catalysis A: General

139

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A commercial HZSM-5 zeolite (Si/Al=16) was submitted to mild acid treatment and we have found that different conclusions regarding the effect of zeolite acidity may be reached depending on the specific method used for preparing the hybrid catalysts when the overall STD process becomes controlled by the methanol synthesis rate on the Cubased catalyst (i.e. using hybrids with a CZA:zeolite mass ratio of 2:1, that is, with an "excess" of acid sites). Thus, for hybrids prepared by mixing the pre-pelletized components, the same CO conversion and product selectivity (with values approaching those predicted by the thermodynamic equilibrium at the studied conditions) with no signs of deactivation during at least 50 h on stream was attained irrespective of the zeolite acidity. By contrast, significant differences in catalyst stability were found for hybrids prepared by grinding the component powders prior to pelletizing, pointing towards the occurrence of detrimental interactions between the CZA and zeolite components during the grinding preparation stage. Moreover, the different TOS behaviors observed between these hybrids depending on the particular zeolite used suggested that the kind and extent of such detrimental interactions should be tightly related to the acidity and/or chemical composition of the ZSM-5 zeolite.

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The interaction effects of dehydration function on catalytic performance and properties of hybrid catalysts upon LPDME process

Cited by 30 publications

References 18 publications

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

The impact of zeolite pore structure on the catalytic behavior of CuZnAl/zeolite hybrid catalysts for the direct DME synthesis

The role of the acidity of alumina prepared by aluminum-carbon black composite for CO hydrogenation to dimethyl ether on hybrid Cu–ZnO–Al2O3/alumina

Direct synthesis of DME from syngas on hybrid CuZnAl/ZSM-5 catalysts: New insights into the role of zeolite acidity

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