Methanol–steam reforming on Cu/ZnO/Al2O3. Part 1: the reaction network

Peppley, Brant A.; Amphlett, J. C.; Kearns, Lyn M.; Mann, R. F.

doi:10.1016/s0926-860x(98)00298-1

Cited by 543 publications

(277 citation statements)

References 12 publications

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“…It can be concluded that the changes of bulk phase and gaseous product composition observed during oxygen addition cycles permit one to distinguish between different active states of copper operative in the Cu/ZnO system. The results support previous assumption based on kinetic analysis of surface reactions that parallel reaction might occur on different active copper phases during methanolsteam reforming ( 8,6). Interestingly, the oxidation and reduction curves of Cu metal in the upper graph in Fig.…”

Section: Steam Reforming Of Methanolsupporting

confidence: 90%

“…Fig. 2 (a) 6 (CO 3 ) 2 ) (27). The influence of the precursor structure which is apparently preserved in the calcined CuO/ZnO precursor can lead to an enhanced reduction rate through the beneficial interaction of various types of defects leading to an increased reactivity of the solid phase.…”

Section: I) In Situ Xrdmentioning

confidence: 99%

“…They have shown that the specific activity is not directly correlated to the Cu metal surface area and concluded that preparation parameters determine to a large extent the activity for a given Cu surface area. In a recent publication by Peppley et al a kinetic model for methanol-steam reforming is presented ( 6). It was found that the methanol steam reforming reaction and the methanol decomposition to CO and hydrogen proceed on different active sites, although the rate-determining step (dehydrogenation of absorbed methoxy groups) is the same in both cases.…”

Section: Effects Of Precursor Preparation and Reduction Conditions Onmentioning

confidence: 99%

“…CO 2 + 3H 2 ) can be regarded as the reversed methanol synthesis reaction. However, a detailed reaction mechanism is still under debate (5,6,7). In a kinetic model by Peppley et al it is assumed that different active phases are responsible for the methanol decomposition, methanol-steam reforming, and the water-gas shift reaction (8).…”

Section: Introductionmentioning

confidence: 99%

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Redox Behavior of Copper Oxide/Zinc Oxide Catalysts in the Steam Reforming of Methanol Studied by in Situ X-Ray Diffraction and Absorption Spectroscopy

Günter

Ressler

Jentoft

et al. 2001

Journal of Catalysis

249

162

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The bulk structure of copper in various binary Cu/ZnO catalysts for steam reforming of methanol under activation and working conditions is studied by in situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). The evolution of bulk phases from CuO/ZnO precursors during activation with hydrogen was studied using temperature programmed reduction (TPR) (448 -523 K, 2 vol-% H 2 with and without water vapor). With decreasing copper content the onset of reduction is shifted from 473 K (pure CuO) to 443 K (40 mol-% Cu) accompanied by a decrease in Cu crystallite sizes (from 210 Å to 40 Å). Using time -resolved in situ XANES measurements at the Cu K edge during TPR experiments the degree of reduction was monitored. It is shown that Cu(I) oxide forms prior to Cu. Adding oxygen to the feed gas leads to the formation of a mixture of Cu(II) and Cu(I) oxide accompanied by a complete loss of activity. After switching back to steam reforming conditions a higher activity is attained while the catalyst shows an increased Cu crystallite size (up to 40%). EXAFS measurements at the Cu K and the Zn K edge indicate a structural disorder of the Cu particles in the medium range order based on increasing Debye-Waller factors for higher Cu-Cu shells . Furthermore, the dissolution of Zn atoms (up to ~ 4 mol-%) in the copper lattice is detected. Upon oxidation/reduction cycles activity is increased, the disorder in the copper particles increases, and Zn segregates out of the copper bulk. A structural model is proposed which ascribes the enhanced activity to structurally disordered (strained) copper particles due to an improved interface interaction with ZnO.

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Section: Steam Reforming Of Methanolsupporting

confidence: 90%

Section: I) In Situ Xrdmentioning

confidence: 99%

Section: Effects Of Precursor Preparation and Reduction Conditions Onmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Redox Behavior of Copper Oxide/Zinc Oxide Catalysts in the Steam Reforming of Methanol Studied by in Situ X-Ray Diffraction and Absorption Spectroscopy

Günter

Ressler

Jentoft

et al. 2001

Journal of Catalysis

249

162

View full text Add to dashboard Cite

show abstract

“…In the literature, copper-based catalysts have received considerable attention for production of H 2 by SRM [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Recent papers have discussed the POM reaction [22][23][24], as well as the combined process for production of H 2 [25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

Production of hydrogen from methanol over Cu/ZnO catalysts promoted by ZrO2 and Al2O3

Agrell

Birgersson

Boutonnet

et al. 2003

Journal of Catalysis

370

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Catalyst development and kinetics for methanol fuel processing

Peppley

Amphlett

Mann

2010

Handbook of Fuel Cells

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The reactions involved in methanol fuel processing are discussed. It is stated that the direct reaction of methanol and steam to form carbon dioxide and hydrogen is the key hydrogen producing reaction. Catalysis by Cu/ZnO/Al 2 O 3 is described in general terms. The literature on the kinetics of methanol–steam reforming is described in detail. Early kinetic models that were adequate for a limited range of operating conditions are discussed. The importance of understanding the surface reaction mechanism for developing models that are valid over wide ranges of conditions is described, followed by a description of the evolution of surface mechanisms for the process leading to a comprehensive kinetic model. The usefulness of this mechanistically‐based model is described in detail. The relative importance of the water–gas shift reaction, in particular, is revealed. Subsequently, the limitations and operating problems associated with Cu‐based catalysts are discussed. Both deactivation and pyrophoric behavior are cited as major problems. Finally, alternatives to Cu‐base catalysts are discussed. These include Ni‐hydrotalcites and Pt on ceria. Although these catalysts have lower activity than Cu‐based catalysts at temperature below 300 °C, their thermal stability at temperatures as high as 390 °C makes them more practical in fuel processors for methanol‐fuelled fuel cell systems.

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Methanol–steam reforming on Cu/ZnO/Al2O3. Part 1: the reaction network

Cited by 543 publications

References 12 publications

Redox Behavior of Copper Oxide/Zinc Oxide Catalysts in the Steam Reforming of Methanol Studied by in Situ X-Ray Diffraction and Absorption Spectroscopy

Redox Behavior of Copper Oxide/Zinc Oxide Catalysts in the Steam Reforming of Methanol Studied by in Situ X-Ray Diffraction and Absorption Spectroscopy

Production of hydrogen from methanol over Cu/ZnO catalysts promoted by ZrO2 and Al2O3

Catalyst development and kinetics for methanol fuel processing

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