Photoelectron-spectroscopic and reactivity investigation of thin Pd–Sn films prepared by magnetron sputtering

Škála, Tomáš; Veltruská, Kateřina; Sedláček, L.; Mašek, K.; Matolı́nová, Iva; Matolín, Vladimı́r

doi:10.1016/j.apsusc.2006.12.017

Cited by 4 publications

(6 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To verify this hypothesis, Pd and Ga core levels were analysed. Pd 3d spectra (not shown) exhibited shapes similar to the previous case (section 3.1) but the FWHMs were slightly lower and the binding energies were higher, similar to their behaviour in other Pd intermetallic systems, see [21] and references therein. The evolution of the Pd 3d 5/2 binding energy is plotted in figure 1(b) by red squares.…”

Section: Pd/ga-ce-o Systemsupporting

confidence: 79%

“…This decrease is less steep, which is most probably caused by an excess of tin in this surface layer (contrary to the gallium case, the amount of tin is so high that there is not only the oxidized but also the metallic, phase present). Also the binding energy of the Pd 3d 5/2 peak (figure 1(b)) lying above 336 eV for all deposition steps of palladium in comparison to the data in [21] suggest an excess of Sn in the Pd-Sn alloy. On the sample of Pd deposited onto a Sn-Ce-O layer with a lower amount of tin (0.07 nm) we expected to see better the effects of the Pd-Sn interaction and the results are very surprising.…”

Section: Pd/sn-ce-o Systemmentioning

confidence: 67%

“…On the sample with 0.07 nm of tin (figures 6(a) and (b)) the presence of palladium causes the appearance of an (inter)metallic feature at lower binding energy that was not present before. This feature can be attributed either to metallic tin or to Pd-Sn intermetallic alloy since the binding energies of Sn in both systems are very similar [21,23] and do not depend strongly on the alloy stoichiometry. However, the formation of the Pd-Sn alloy is In figure 3 the evolution of the Ce 3+ /Ce 4+ and of the D ratio is plotted.…”

Section: Pd/sn-ce-o Systemmentioning

confidence: 93%

See 2 more Smart Citations

Palladium interaction with CeO₂, Sn–Ce–O and Ga–Ce–O layers

Škála

Šutara

Škoda

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Using photoemission, we have studied the interaction of palladium with thin layers of stoichiometric ceria (Ce(4+) character) and two mixed oxides, Ga-Ce-O and Sn-Ce-O, where cerium in the Ce(3+) oxidation state is present. Palladium was found to partially reduce the CeO(2) layer by introducing oxygen vacancies most probably in the vicinity of the growing Pd particles. In mixed oxide systems palladium very strongly interacts with both added metals-gallium and tin-leading to a breaking of metal-ceria bonds and the establishment of Pd-Ga(Sn) intermetallic compounds. As a consequence the ceria reoxidizes back to a Ce(4+) oxidation state.

show abstract

Section: Pd/ga-ce-o Systemsupporting

confidence: 79%

Section: Pd/sn-ce-o Systemmentioning

confidence: 67%

Section: Pd/sn-ce-o Systemmentioning

confidence: 93%

See 1 more Smart Citation

Palladium interaction with CeO₂, Sn–Ce–O and Ga–Ce–O layers

Škála

Šutara

Škoda

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…It is thus interesting to consider tin; its role in these systems is usually connected (correlated) with the modification of Pd d-band and consequently related with particle adsorption properties. X-ray photoelectron spectroscopy (XPS) investigation of Pd-Sn alloy indicated a strong bimetallic interaction resulting in a noble metal-like electronic structure [35][36][37][38]. Therefore, a great effort has been made to investigate bimetallic systems based on palladium and tin in order to prepare novel catalysts for various applications .…”

Section: Introductionmentioning

confidence: 99%

Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al2O3

et al. 2021

View full text Add to dashboard Cite

One of the key factors for producing highly dispersed controlled nanoparticles is the method used for metal deposition. The decomposition of metal-organic precursors is a good method for deposition of metal nanoparticles with very small sizes and narrow size distributions on the surface of various supports. The preparation process of Pd and bimetallic Pd-Sn nanoparticles supported onto γ‑Al2O3 is considered. The samples were prepared by diffusional co-impregnation of the γ‑Al2O3 support by using organometallic Pd(acac)2 and Sn(acac)2Cl2 precursors. To achieve the formation of Pd and bimetallic Pd-Sn nanoparticles on the support surface, the synthesized samples were then subjected to thermal decomposition under Ar (to decompose the organometallic bound to the surface while keeping the formed nanoparticles small) followed by an oxidation in O2 (to eliminate the organic compounds remaining on the surface) and a reduction in H2 (to reduce the nanoparticles oxidized during the previous step). A combination of methods (ICP-OES, TPR-H2, XPS, TEM/EDX) was used to compare the physical-chemical properties of the synthesized Pd and bimetallic Pd-Sn nanoparticles supported on the γ‑Al2O3. The three samples exhibit narrow size distribution with a majority on nanoparticles between 3 and 5 nm. Local EDX measurements clearly showed that the nanoparticles are bimetallic with the expected chemical composition and the measured global composition by ICP-OES. The surface composition and electronic properties of Pd and Sn on the γ-Al2O3 support were investigated by XPS, in particular the chemical state of palladium and tin after each step of thermal decomposition treatments (oxidation, reduction) by the XPS method has been carried out. The reducibility of the prepared bimetallic nanoparticles was measured by hydrogen temperature programmed reduction (TPR-H2). The temperature programmed reduction TPR-H2 experiments have confirmed the existence of strong surface interactions between Pd and Sn, as evidenced by hydrogen spillover of Pd to Sn (Pd-assisted reduction of oxygen precovered Sn). These results lead us to propose a mechanism for the formation of the bimetallic nanoparticles.

show abstract

“…В частности, в литературе опубликовано много исследований, посвященных биметаллическим системам Pd-Sn. Биметаллическая система Pd-Sn характеризуется сильным взаимодействием между Pd и Sn за счет гибридизации sp-орбиталей Pd и Sn, что приводит к образованию сплавов Pd-Sn электронной структуры, подобной благородным металлам [1][2][3][4]. Как правило, используются различные способы получения биметаллических наночастиц Pd-Sn: нанесение обоих металлов на оксидный носитель, таких как оксид алюминия и силикагель [5], а также нанесение палладия на SnO2 [6].…”

Section: Introductionunclassified