The role of ZnO in Cu/ZnO methanol synthesis catalysts — morphology effect or active site model?

Choi, Yeongsoo; Futagami, Katsuya; Fujitani, Tadahiro; Nakamura, Junji

doi:10.1016/s0926-860x(00)00712-2

Cited by 168 publications

(62 citation statements)

References 20 publications

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“…An optimized CO 2 hydrogenation catalyst might thus require an increase in the Zn-promoted Cu sites active in methanol formation at the expense of the unpromoted clean Cu sites that likely form CO [31,47]. However, it seems that the former have unique and very special structural properties as represented for instance by the fully Zn-covered surface step, which can be used as model for the active site capable of explaining the ''Cu-Zn synergy'' [14,25].…”

Section: Methanol Synthesismentioning

confidence: 99%

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

Kunkes

Studt

Abild‐Pedersen

et al. 2015

Journal of Catalysis

262

211

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This work is dedicated to the memory and achievements of Dr. Haldor Topsøe.Keywords: H/D substitution Methanol Copper Reverse water gas shift DFT Kinetics Mechanism CO 2 hydrogenation a b s t r a c t H/D exchange experiments on a Cu/ZnO/Al 2 O 3 catalyst have shown that methanol synthesis and RWGS display a strong thermodynamic isotope effect, which is attributed to differences in the zero-point energy of hydrogenated vs. deuterated species. The effect is larger for methanol synthesis and substantially increases the equilibrium yield in deuterated syngas. In the kinetic regime of CO 2 hydrogenation, an inverse kinetic isotope effect of H/D substitution was observed, which is stronger for methanol synthesis than for CO formation suggesting that the two reactions do not share a common intermediate. Similar observations were also made on other catalysts such as Cu/MgO, Cu/SiO 2 , and Pd/SiO 2 . In contrast to CO 2 hydrogenation, the CO hydrogenation on Cu/ZnO/Al 2 O 3 did not show such a strong kinetic isotope effect indicating that methanol formation from CO 2 does not proceed via consecutive reverse water gas shift and CO hydrogenation steps. The inverse KIE is consistent with formate hydrogenation being the rate-determining step of methanol synthesis from CO 2 . Differences in the extent of product inhibition by water, observed for methanol synthesis and reverse water gas shift indicate that the two reactions proceed on different surface sites in a parallel manner. The consequences for catalyst design for effective methanol synthesis from CO 2 are discussed.

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Section: Methanol Synthesismentioning

confidence: 99%

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

Kunkes

Studt

Abild‐Pedersen

et al. 2015

Journal of Catalysis

262

211

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“…[4] It is widely accepted that zinc oxide can improve the dispersion of copper and thereby the catalytic activities. [5] Copper-zinc oxide nanocomposites are usually prepared by co-precipitation from aqueous solutions. Typically, a mixed solution of copper and zinc salts (usually nitrates or acetates) is prepared and the precipitation of both carbonates is induced by addition of sodium or ammonium carbonate whilst stirring, followed by drying and calcination.…”

Section: Introductionmentioning

confidence: 99%

A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)₃]

2005

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Keywords: Cyanides / Copper / Zinc / Thermochemistry / EXAFS spectroscopy Copper-zinc nanocomposites were prepared by thermolysis of copper-zinc cyanides under mild conditions. Two different routes were used for the preparation of the cyanide complex: A batch precipitation method and the continuous overflow precipitation method. The thermolysis of the cyanides was studied in-situ by thermogravimetry coupled with infrared spectroscopy (TG-IR) and by thermogravimetry coupled with mass spectroscopy (TG-MS). The structure of the nanocomposites was investigated by X-ray powder diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). Geometric models were suggested on the atomic scale based on EXAFS results for the precursor, the mixed oxides (CuO/

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“…A synergism between Cu 0 and Cu + sites is the most adopted explanation for the activity of Cu/ZnO-promoted catalysts [38,61,67,68]; however, Cu 0 sites [69,70] and/or Cu-Zn alloy [71][72][73] have been proposed to have a catalytic role as well.…”

Section: Us-assisted Synthesis Of Cu-zno Catalysts and Of Their Impromentioning

confidence: 99%

Microwave, Ultrasound, and Mechanochemistry: Unconventional Tools that Are Used to Obtain “Smart” Catalysts for CO2 Hydrogenation

Manzoli

Bonelli

2018

Catalysts

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Abstract:The most recent progress obtained through the precise use of enabling technologies, namely microwave, ultrasound, and mechanochemistry, described in the literature for obtaining improved performance catalysts (and photocatalysts) for CO 2 hydrogenation, are reviewed. In particular, the main advantages (and drawbacks) found in using the proposed methodologies will be discussed and compared by focusing on catalyst design and optimization of clean and efficient (green) synthetic processes. The role of microwaves as a possible activation tool used to improve the reaction yield will also be considered.

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The role of ZnO in Cu/ZnO methanol synthesis catalysts — morphology effect or active site model?

Cited by 168 publications

References 20 publications

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)₃]

Microwave, Ultrasound, and Mechanochemistry: Unconventional Tools that Are Used to Obtain “Smart” Catalysts for CO2 Hydrogenation

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The role of ZnO in Cu/ZnO methanol synthesis catalysts — morphology effect or active site model?

Cited by 168 publications

References 20 publications

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

Hydrogenation of CO2 to methanol and CO on Cu/ZnO/Al2O3: Is there a common intermediate or not?

A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)3]

Microwave, Ultrasound, and Mechanochemistry: Unconventional Tools that Are Used to Obtain “Smart” Catalysts for CO2 Hydrogenation

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A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)₃]