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Stone, F. S.

doi:10.1023/a:1023592407825

Cited by 105 publications

(52 citation statements)

References 22 publications

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“…[14]. It is interesting to note that the reverse water gas shift activities reported by Stone and Waller [16] as a function of Cu:Zn ratio follow a trend, which is very similar to the evolution of Cu surface areas observed for our samples shown in Fig. 2.…”

Section: Resultssupporting

confidence: 87%

“…4). Upon co-precipitation, first an amorphous precipitate is formed, which is transformed into the crystalline precursor during the ageing period in the mother liquor, typically after a few hours [3,8,9]. This crystallization is accompanied by a minimum in pH, an increase on turbidity and a change of color from blue to bluish green (after 65 min in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Finally, the catalyst is activated by reduction of the Cu oxide component. A large body of work reports on the complex dependencies of the catalyst's properties on the various parameters of the precipitation and ageing process [3][4][5][6][7][8][9] and this phenomenon is referred to as the chemical memory of the system [9]. The detailed work of Waller et al [3] identified zincian malachite, (Cu,Zn) 2 (OH) 2 CO 2 , as the relevant precursor phase, while other authors suggest that the presence of aurichalcite, (Cu,Zn) 5 (OH) 6 (CO 3 ) 2 , is essential for preparation of an active Cu/ZnO catalyst [10,11].…”

Section: Introductionmentioning

confidence: 99%

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Meso- and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts

Behrens

2009

Journal of Catalysis

228

203

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A concept is presented, which helps to rationalize the success of the industrially applied preparation route for Cu/ZnO/(Al2O3) catalysts. Many studies can be found in the open literature, which describe the critical dependency of the final catalyst's properties on precursor chemistry. In line with previous reports, this concept identifies zincian malachite as the relevant precursor phase and includes a simple relation of precursor crystal structure and final Cu surface area. It comprises two hierarchical microstructure-directing effects, for which particle morphology and degree of Cu 2+ substitution by Zn 2+ in the zincian malachite phase are the key properties: (i) meso-structuring of the precursor phase upon ageing of the coprecipitate in the mother liquor and (ii) nano-structuring of the oxide phase upon decomposition. Consequences for further optimization of the Cu,Zn,Al system are discussed.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Meso- and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts

Behrens

2009

Journal of Catalysis

228

203

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“…A linear relationship between the activity of the catalyst and the surface area of metallic Cu was obtained. 34 Additionally, Chen et al have reported that Cu/SiO 2 with a potassium promoter offers better catalytic activity (12.8% of CO 2 conversion at 600 1C) than that without promoter (5.3% of CO 2 conversion at 600 1C). 35 The created new active sites located at the interface between copper and potassium favor the formation of formate (HCOO) species, which is the key intermediate for CO production.…”

Section: Metal-based Heterogeneous Catalystsmentioning

confidence: 99%

Recent advances in catalytic hydrogenation of carbon dioxide

et al. 2011

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Owing to the increasing emissions of carbon dioxide (CO 2 ), human life and the ecological environment have been affected by global warming and climate changes. To mitigate the concentration of CO 2 in the atmosphere various strategies have been implemented such as separation, storage, and utilization of CO 2 . Although it has been explored for many years, hydrogenation reaction, an important representative among chemical conversions of CO 2 , offers challenging opportunities for sustainable development in energy and the environment. Indeed, the hydrogenation of CO 2 not only reduces the increasing CO 2 buildup but also produces fuels and chemicals. In this critical review we discuss recent developments in this area, with emphases on catalytic reactivity, reactor innovation, and reaction mechanism. We also provide an overview regarding the challenges and opportunities for future research in the field (319 references).

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“…An effective and industrially applied preparative route for these catalysts is via a multi-step synthesis involving co-precipitation of mixed Cu/Zn hydroxycarbonate precursors, calcination to give a mixture of oxides and reduction of the CuO component. A vast number of studies on this system, performed by many different research groups, have shown that the synthetic parameters during the very early stages of the preparation process crucially affect the physicochemical properties of the precursor material [1][2][3][4][5][6][7][8][9][10][11][12] and, in turn, the catalytic activity of the final catalyst. This phenomenon is termed the "chemical memory" of the system.…”

Section: Introductionmentioning

confidence: 99%

Minerals as Model Compounds for Cu/ZnO Catalyst Precursors: Structural and Thermal Properties and IR Spectra of Mineral and Synthetic (Zincian) Malachite, Rosasite and Aurichalcite and a Catalyst Precursor Mixture

et al. 2009

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The Cu/ZnO system is a model for Cu/ZnO/Al2O3 catalysts, which are employed industrially for the synthesis of methanol. These catalysts are usually prepared from mixed basic carbonate precursors. A complex phase mixture, with constituents structurally related to the minerals rosasite andaurichalcite, is present at the industrially applied composition (Cu/Zn ≈ 70:30). Using minerals and phase‐pure synthetic samples as references, a comprehensive characterisation of such a phase mixture, including the determination of the individual compositions of the different phases, has been attempted by complementary analytical laboratory techniques (XRD, TGA, IR). The results are critically discussed in light of the complexity of the system. A thermally very stable carbonate species ― well‐known for mixed synthetic systems ― is also detected for the mineral reference samples. Significant amounts of amorphous phases are found to be present in the synthetic zincian malachite sample but not in synthetic aurichalcite or the catalyst precursor. A simplified explanation for the shift of the characteristic 20$\bar {1}$ reflection of the malachite structure as a function of Zn incorporation based on the varying average Jahn–Teller distortion of the MO6 octahedra is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Cited by 105 publications

References 22 publications

Meso- and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts

Meso- and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts

Recent advances in catalytic hydrogenation of carbon dioxide

Minerals as Model Compounds for Cu/ZnO Catalyst Precursors: Structural and Thermal Properties and IR Spectra of Mineral and Synthetic (Zincian) Malachite, Rosasite and Aurichalcite and a Catalyst Precursor Mixture

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