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1
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Hydrogen adsorption on Pd(133) surface

100%
Tomaszewska A., Stępień Z. a.
Open Physics
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2009
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vol. 7
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issue 2
286-290
EN
An approach based on measurements of the total energy distribution (TED) of field emitted electrons is used in order to examine properties of the Pd(133) from the aspect of hydrogen adsorption. The most favourable sites offered to a hydrogen atom to be adsorbed are indicated and an attempt to ascribe the peaks of the enhancement factor R in the TED spectrum to the specific adsorption sites is made.
2
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Asymmetric Pd-catalyzed allylic substitution using a large sugar-based monophosphite ligand library. Scope and limitations.

100%
Alegre S., Matta Y., Diéguez M., Pàmies O.
Asymmetric Catalysis
|
2013
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vol. 1
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issue 1
EN
We have applied a modular sugar-based phosphite ligand library for the Pd-catalyzed allylic substitution reactions of several substrates. These ligands are derived from D-(+)-glucose, D-(+)-galactose and D-(+)- fructose, which lead to a wide range of sugar backbones, and contain several substituents at the C-3 carbon of the furanoside backbone and several substituents/ configurations in the biaryl moiety, with different steric and electronic properties. Systematic variation of the ligand parameters indicates that the catalytic performance (activities and enantioselectivities) is highly affected by sugar backbone, the substituents at the C-3 carbon of the furanoside backbone, the configurations at the C-3 and C-4 carbons of the ligand backbone and the type of substituents/configurations in the biaryl phosphite moiety as well as the substrate type. For disubstituted substrates moderate enantioselectivities (up to 72%) were achieved using ligand L8d, while for monosubstituted substrates the highest enantioselectivities (up to 40%) were obtained using ligand L9a.
3
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Optical and electrical properties of nanocrystalline TiO2:Pd semiconducting oxides

100%
Sieradzka K., Kaczmarek D., Domaradzki J., Prociów E., Mazur M., Górnicka B.
Open Physics
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2011
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vol. 9
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issue 2
313-318
EN
Electrical and optical properties of TiO2:Pd thin films deposited from Ti-Pd mosaic targets sputtered in reactive oxygen plasma have been studied. The properties were investigated for thin films with the Pd amount of 5.5 at. %, 8.4 at. % and 23 at. %. Based on resistivity measurements a drop from 103 down to almost 10−3Ωcm has been recorded when the Pd amount was varied from 5.5 at. % to 23 at. %, respectively. Moreover, it was shown that doping with different amounts of Pd results in the possibility of obtaining both types of electrical conduction: n-type for the TiO2 with 5.5 at. % and 8.4 at. % of Pd and p-type for the TiO2 with 23 at. % of Pd thin films. From optical measurements it has been found that as the Pd amount was increased the transmission through the thin films was reduced and position of the fundamental absorption edge was shifted toward a longer wavelength range of up to 600 nm. The optical band gap was calculated for direct and indirect transitions from optical absorption spectra. Structural properties were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The XRD patterns displayed occurrence of the crystalline, TiO2-rutile for lower Pd amounts (5.5 at. %, 8.4 at. %), while the TiO2:Pd (23 at. %) thin films displayed XRD-amorphous behaviour. Images obtained from AFM displayed dense, nanocrystalline structure with homogenous distribution of crystallites. Additionally performed secondary ion mass spectroscopy investigation confirmed homogenous distribution of Pd in the whole thickness of the prepared thin films.
4
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Topography and nanomechanical properties of Pd-C films

88%
Rymarczyk J., Czerwosz E., Richter A.
Open Physics
|
2011
|
vol. 9
|
issue 2
300-306
EN
Atomic force microscopy (AFM) topographical studies and results of nanoindentation experiment for several palladium-carbon films (Pd-C film) deposited on various substrates and with varying palladium content are presented. Pd-C films were prepared by a physical vapor decomposition (PVD) process and next were modified by a chemical vapor decomposition (CVD) method to obtain carbonaceous porous structure with dispersed palladium nanograins and a variation in roughness. The dependence of film topography on the kind of substrate such as Al2O3, Mo polycrystalline foil and fused silica was studied by AFM. Nanomechanical properties such as hardness and the reduced indentation modulus were determined by nanoindentation. A comparison of these values for films with different Pd content deposited on various substrates is presented.
5
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Topography, mechanical and tribological properties of nanocomposite carbon-palladium films

88%
Rymarczyk J., Kolodziejczyk L., Czerwosz E.
Open Physics
|
2015
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vol. 13
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issue 1
EN
In this work, the differences in nanomechanical properties, topography and morphology of carbonpalladium (C-Pd) films were studied. These films were prepared with a Physical Vapour Deposition method on various substrates with different technological parameters. We show that duration of the PVD process is a crucial factor affecting the palladium content in these films. The differences in thickness of films depend on the distance between source boats and substrates. The nanomechanical properties of C-Pd films were studied with nanoindentation. Their topography and morphology was ascertained with Atomic Force Microscopy and Scanning Electron Microscopy. It was found that the mechanical properties of C-Pd films depend on the content of palladium and on the morphology and topography of these films. The various types of carbon-palladium films containing palladium nanograins incorporated in a carbon matrix that were, investigated in this paper, seem to be promising materials for numerous applications.
6
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Molten solvent extraction behavior of palladium with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone at 60 °C

75%
Peng B., Guo X., Mao X., Gao J.
Open Chemistry
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2007
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vol. 5
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issue 3
912-921
EN
The solvent extraction behavior of precious metal palladium with 1-phenyl-3-methyl-4-benzoyl-5-pyrazone (PMBP) into molten paraffin wax has been studied in the temperature range from 55 to 75 °C. The complex consisting of PMBP and palladium was extracted into molten wax phase in the pH range from 1.0 to 3.5 at 60 °C. The extraction efficiency was up to 97% at the experimental pH. The stoichiometry of the extracted species of palladium was determined on the basis of slope analysis method. The effects of time to achieve equilibrium, temperature, and extractant concentration on the extraction were discussed. The thermodynamic data indicate that the extraction is an endothermic reaction and the increase of temperature promotes the extraction of palladium into molten paraffin wax and the extraction of palladium with PMBP is entropy controlled at high temperatures. [...]
7
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Electrocatalytical Properties of Palladium-Decorated Cobalt Coatings Obtained by Electrodeposition and Galvanic Displacment

75%
Skibińska K., Kutyła D., Kołczyk K., Kwiecińska A., Kowalik R., Żabiński P.
Archives of Metallurgy and Materials
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2018
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vol. 63
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issue 3
8
Content available remote

The Influence of Technological PVD Process Parameters on the Topography, Crystal and Molecular Structure of Nanocomposite Films Containing Palladium Nanograins

75%
Rymarczyk J., Czerwosz E., Kozłowski M., Dłużewski P., Kowalski W.
Polish Journal of Chemical Technology
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2014
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vol. 16
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issue 3
18-24
EN
The paper describes the preparation and characteristics of films composed of Pd nanograins placed in carbonaceous matrix. Films were obtained in PVD (Physical Vapor Deposition) process from two sources containing: the first one - fullerene powder and the second one - palladium acetate. The topographical, morphological and structural changes due to different parameters of PVD process were studied with the use of Atomic Force Microscopy and Scanning Electron Microscopy, whereas the structure was studied with the application of the Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy methods. It was shown that topographical changes are connected with the decomposition ratio of Pd acetate as well as the form of carbonaceous matrix formed due to this decomposition. Palladium nanograins found in all films exhibit the fcc structure type and their diameter changes from 2 nm to 40 nm depending on the PVD process parameters.
9
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Surface acoustic wave hydrogen gas sensor based on layered structure of palladium/metal-free phthalocyanine

75%
Jakubik W. P., Urbańczyk M., Maciak E., Pustelny T.
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2008
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vol. 56
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issue 2
10
Content available remote

ToF-SIMS studies of the surface of Pd/ZrO2-TiO2catalyst used in the hydrodechlorination process

75%
Grams J., Góralski J., Kleczewska J., Szczepaniak B., Paryjczak T.
Polish Journal of Chemical Technology
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2007
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vol. 9
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issue 3
81-85
EN
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used in order to obtain the information about the surface composition of Pd/ZrO2-TiO2 catalyst and to estimate the changes in the concentration of particular components on its surface during the hydrodechlorination of CCl4. The results demonstrated that the hydrodechlorination process led to the increase in the concentration of chlorine and the drop in the amount of surface accessible palladium, while the quantity of Pd-Cl bounds did not change considerably. It suggested that the presence of ZrO2 protected the surface of the studied catalyst against the formation of PdCl2.
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