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Norman, Aaron; Perrichon, V.; Bensaddik, A.; Lemaux, Sylvain; Bitter, Harry; Koningsberger, D.C.

doi:10.1023/a:1016621401560

Cited by 32 publications

(20 citation statements)

References 20 publications

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“…As presently well-established, [24][25][26] in the presence of highly dispersed rhodium, an alternative, much faster mechanism of generating atomic hydrogen species on the oxide surfaces, the spillover, becomes operative. Consequently to this, the kinetic limitations for hydrogen chemisorption on the bare oxides are overcome, and a very significant increase of their reduction rate occurs.…”

Section: Tpr-ms Studies On the Oxide-supported Rhodium Samplesmentioning

confidence: 95%

Redox Behavior of Thermally Aged Ceria−Zirconia Mixed Oxides. Role of Their Surface and Bulk Structural Properties

et al. 2006

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The relationship existing between aging conditions, redox behavior, and surface/bulk structural properties of two thermally aged ceria-zirconia mixed oxides, CZ-MO and CZ-SO, is analyzed. The samples were prepared by applying to a fresh Ce 0.62 Zr 0.38 O 2 mixed oxide two alternative aging routines consisting of a reduction with H 2 at 1223 K (5 h), followed by either a mild, CZ-MO, or severe, CZ-SO, re-oxidation treatment. By combining high-resolution electron microscopy and a number of chemical charcterization techniques, it is shown that the nanostructure of the aged oxides, specifically the total amount and surface presence of the phase exhibiting an ordered cationic sublattice (κ-like phase), is a key factor in determining their redox response. In the low-temperature reduction range (T redn e 773 K), the enhanced reducibility of the CZ-MO sample is proposed to be kinetically controlled by its surface structure mainly consisting of the κ-like phase. In accordance with the reported results, the surface activation of the H 2 molecule, much faster on the CZ-MO sample, is proposed to be the rate controlling step of the overall reduction process. This proposal was further confirmed by the dramatic downward shift observed in the temperatureprogrammed reduction diagrams recorded for the corresponding oxide-supported rhodium samples. By contrast, in the high-temperature reduction range (T redn g 973 K), the observed difference of reducibility, higher in the case of the CZ-MO sample, is interpreted as due to thermodynamic factors related to the nature of the predominant cationic sublattice structure, ordered for CZ-MO and disordered in the case of the CZ-SO sample.

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Section: Tpr-ms Studies On the Oxide-supported Rhodium Samplesmentioning

confidence: 95%

Redox Behavior of Thermally Aged Ceria−Zirconia Mixed Oxides. Role of Their Surface and Bulk Structural Properties

et al. 2006

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“…Finally, some concluding remarks summarising the progress made in the understanding of the strong metal/support interaction phenomena exhibited by the NM/Ce(M)0 2 -x catalysts will be presented in section 4.3.4. electronic conductivity measurements (204,263), V-UV spectroscopy (331,332), FTIR spectroscopy (76,311,333,334), X-ray absorption spectroscopy (XAS) (93,205,289,328,335,336), and magnetic balance (71,93,193,195,204,217,218,331,(337)(338)(339)(340). Chemical techniques, like the temperature programmed reduction (TPR) (27)(28)(29)58,61,73,110,186,201,219,248,337,338,(341)(342)(343)(344)(345)(346), and, re-oxidation studies by oxygen pulses (98,…”

Section: Some Challenging Aspects Of These Characterisation Studiesmentioning

confidence: 99%

“…not modified by the different reduction treatments. This is the case of the ceria-zirconia system, for which a number of magnetic balance studies have already been reported (93,310,333,337,338,(347)(348)(349). Also very important, the Faraday microbalance allows the magnetic measurements to be performed in a wide range of temperatures, under varying chemical environments (71,193,195,204,340).…”

Section: Faraday Magnetic Balance Studiesmentioning

confidence: 99%

“…A number of magnetic balance studies carried out on Rh/Ce0 2 (193,195,217,218), Pd/Ce0 2 (71), and Pd/Ceo.esZro^Oj (93) catalysts, an example of which is presented in Table 4.3, have clearly shown that large amounts of hydrogen can be transferred to support, even at room temperature. Consequently, as reported in Table 4.5, conventional chemisorption studies at 298 K. may lead to H/M » 1.…”

Section: H 2 Chemisorption Studiesmentioning

confidence: 99%

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Chemical and Nanostructural Aspects of the Preparation and Characterisation of Ceria and Ceria-Based Mixed Oxide-Supported Metal Catalysts

Bernal

Calvino

Gatica

et al. 2002

Catalysis by Ceria and Related Materials

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“…45 Óvári és munkatársai megfigyelték, hogy a Co/CeO2(111) rendszerben a Co a hordozó redukcióját okozza, mialatt a fém Co részlegesen oxidálódott. Az etanollal való reakció alatt, hőmérséklet emelés hatására mindkét katalizátorkomponens reduká-lódott.…”

Section: Mintákunclassified

CeO2 hordozós Rh-Co katalizátorok felületi és morfológiai jellemzése

Varga

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Untitled

Cited by 32 publications

References 20 publications

Redox Behavior of Thermally Aged Ceria−Zirconia Mixed Oxides. Role of Their Surface and Bulk Structural Properties

Redox Behavior of Thermally Aged Ceria−Zirconia Mixed Oxides. Role of Their Surface and Bulk Structural Properties

Chemical and Nanostructural Aspects of the Preparation and Characterisation of Ceria and Ceria-Based Mixed Oxide-Supported Metal Catalysts

CeO2 hordozós Rh-Co katalizátorok felületi és morfológiai jellemzése

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