Identification of platinum phases on γ-alumina by XPS

Shyu, J.Z.; Otto, K.

doi:10.1016/0169-4332(88)90085-2

Cited by 140 publications

(77 citation statements)

References 10 publications

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“…However, reduction at 773 K caused a strong decrease in the saturation coverage value from 49 to 32 µmol CO/g (also detected by XPS), in agreement with other Pt-Sn (1:1) microcalorimetric studies [15,23,39]. Since Mössbauer results indicate the presence of Pt-Sn alloy after reduction at 773 K, one could expect to find changes in initial adsorption heats of CO on platinum.…”

Section: Co Adsorption Microcalorimetrysupporting

confidence: 69%

Effect of Sn addition to Pt/CeO2–Al2O3 and Pt/Al2O3 catalysts: An XPS, 119Sn Mössbauer and microcalorimetry study

Serrano‐Ruiz

Huber

Sánchez-Castillo

et al. 2006

Journal of Catalysis

141

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The effect of Sn addition to Pt/CeO 2 -Al 2 O 3 and Pt/Al 2 O 3 catalysts was studied with X-ray photoelectron spectroscopy (XPS), 119 Sn Mössbauer spectroscopy and adsorption microcalorimetry of CO at room temperature. Catalysts were reduced in situ at 473 ("non-SMSI state") and 773 K ("SMSI state"). 119 Sn Mössbauer and XPS results indicated that the presence of cerium in bimetallic catalysts inhibited reduction of tin.Furthermore, it was found that tin facilitated reduction of cerium (IV) to cerium (III).Microcalorimetric analysis indicated that cerium addition caused the appearance of a more heterogeneous distribution of active sites, whereas tin addition led to a higher homogeneity of these sites.

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Section: Co Adsorption Microcalorimetrysupporting

confidence: 69%

Effect of Sn addition to Pt/CeO2–Al2O3 and Pt/Al2O3 catalysts: An XPS, 119Sn Mössbauer and microcalorimetry study

Serrano‐Ruiz

Huber

Sánchez-Castillo

et al. 2006

Journal of Catalysis

141

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“…These values are lower than the values usually found for Pt oxide or metallic Pt. 16 After ageing in air at 1000°C the Pt 4d 5/2 signal intensity from the bimetallic PtRh-CeZr-Al catalyst is comparable to the Rh 3d transition and the peak appears at the binding energy of 314.1 eV. In the H 2 -reduction the peak is shifted to a lower binding energy of 313.5 eV.…”

Section: Resultsmentioning

confidence: 91%

The effect of platinum on the reducibility of Rh oxides on CeZr modified alumina supported automotive catalysts

Polvinen

Vippola

Valden

et al. 2004

Surface & Interface Analysis

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The reducibility of Rh oxide on Rh-only and Pt-Rh catalysts was investigated. The catalyst washcoats were composed of alumina modified by La and Ce-Zr mixed oxide. The catalyst ageing was performed in air at 1000• C for 3 h. In order to study the synergistic effect of Pt and Rh on the reducibility of Rh oxide, the propensity of the noble metal oxides to reduction was investigated by exposing the fresh and aged catalysts to 400 mbar of H 2 at 300 • C. XPS was used to observe the changes in chemical state of the noble metals and TEM and XRD were employed to determine the catalyst composition and morphology. Differences were revealed in the behaviour of Rh-only and Pt-Rh catalysts in H 2 -reduction. Rhodium supported on alumina-containing washcoats without Pt was found to react with the support at elevated temperatures to form a reduction-resistive oxide phase. On the Pt-Rh bimetallic catalyst Rh was found to be partly reducible after air ageing and the Rh 3d transition emerged with an unusually low binding energy after H 2 -reduction. Pt-Rh alloy particles were also formed in air ageing.

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“…Here, Pt4d rather than Pt4f data were analyzed, due to the strong interference caused by the Al2p peak [15,38]. The raw data were deconvoluted into three peaks assigned to Pt 4+ [39][40][41], Pt 2+ [42], and Pt 0 [40]. As shown in Figure 14 and Figure 14.…”

Section: Xps Characterization Of Pt Speciesmentioning

confidence: 99%

Pt/MOx/SiO2, Pt/MOx/TiO2, and Pt/MOx/Al2O3 Catalysts for CO Oxidation

et al. 2015

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Conventional supported Pt catalysts have often been prepared by loading Pt onto commercial supports, such as SiO2, TiO2, Al2O3, and carbon. These catalysts usually have simple metal-support (i.e., Pt-SiO2) interfaces. To tune the catalytic performance of supported Pt catalysts, it is desirable to modify the metal-support interfaces by incorporating an oxide additive into the catalyst formula. Here we prepared three series of metal oxide-modified Pt catalysts (i.e., Pt/MOx/SiO2, Pt/MOx/TiO2, and Pt/MOx/Al2O3, where M = Al, Fe, Co, Cu, Zn, Ba, La) for CO oxidation. Among them, Pt/CoOx/SiO2, Pt/CoOx/TiO2, and Pt/CoOx/Al2O3 showed the highest catalytic activities. Relevant samples were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), CO temperature-programmed desorption (CO-TPD), O2 temperature-programmed desorption (O2-TPD), and CO2 temperature-programmed desorption (CO2-TPD).

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Identification of platinum phases on γ-alumina by XPS

Cited by 140 publications

References 10 publications

Effect of Sn addition to Pt/CeO2–Al2O3 and Pt/Al2O3 catalysts: An XPS, 119Sn Mössbauer and microcalorimetry study

Effect of Sn addition to Pt/CeO2–Al2O3 and Pt/Al2O3 catalysts: An XPS, 119Sn Mössbauer and microcalorimetry study

The effect of platinum on the reducibility of Rh oxides on CeZr modified alumina supported automotive catalysts

Pt/MOx/SiO2, Pt/MOx/TiO2, and Pt/MOx/Al2O3 Catalysts for CO Oxidation

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