PT structures

GP 1] [R 1] A comparison of four micro reactors with different Pt loadings (Pt impregnated on anodically oxidized alumina support) and different Pt structures confirmed that cluster size has an impact on the single Pt-atom activity (6 vol.-% NHj, 88 vol.-% O2, balance He 0.51 ms 260-380 °C) [28, 98]. At low Pt loadings, isolated atoms are formed. Calculated ammonia consumption rates amount to 20 s at 300 °C. At high Pt loadings, clusters are formed. Turn over frequencies (TOP) of about 40 s are determined. 

Ashwell GJ, Sambles JR, Martin AS, Parker WG, Szablewski M (1990) Rectifying characteristics of Mg I (C16H33-Q3CNQ LB film) I Pt structures. J Chem Soc Chem Commun 1374-1376... 

Rectifying characteristics of Mg[(C16H33Q3CNQ LB film)]Pt structures. J Chem Soc Chem Commun 1374... 

EXAFS experiments of Pt/Si02 and tin-modified platinum catalysts demonstrate that Sn addition has strong effects on Pt structures. The results obtained from the fit of EXAFS spectra gave us important information on the structures present in... 

MM7525 99SM(101)11), although the emission of substituted PTs is not very predictable due to the interplay of several factors (steric effects, regioregularity, electronic effects, side-chain crystallization, etc.), the full visible range of PL and EL emission, from red to blue, can be covered by variations of the PT structure via substituents in 3,4-positions. 

The PT structure has filled P layers and one T layer filled between P layers. Zinc sulfide has two modifications zinc blende or sphalerite... 

Figure 19.20 Piezoelectric vibration maps of phase ((a), (c)) and amplitude ((b), (d)) (3x3 /um2) of a fatigued Pt-PZT-Pt structure after positive ((a), (b)) and negative ((c), (d)) poling. Bright and dark phase areas correspond to bottom-to-top and top-to-bottom polarization orientations, respectively.

Jellinek has pointed out also that the tetragonal structure of coop-erite, PtS, is related to NiAs. In diamagnetic PtS (d8), four d-orbitals are doubly occupied and one is empty. Therefore, two anions from a hypothetical octahedron have been removed, and the cation is in a square-planar coordination the anion is coordinated by four cations that form a deformed tetrahedron. The cooperite structure is shown in Figure 7. The relationship between the NiS and PtS structure is similar to that between... 

Relatively little is known about anhydrous oxides of palladium. The only well-characterized simple oxide is PdO, which has the PtS structure with four coplanar Pd-O distances of 2.01A (4, 21). Recently, Guiot (1) presented x-ray evidence suggesting that a new palladium oxide surface compound is formed as an intermediate step when palladium metal is oxidized in air to PdO. However, the stoichiometry of this compound is unknown, since it can be obtained only as a minor constituent, with major amounts of Pd metal and PdO. Higher anhydrous oxides (e.g., Pd02) have been reported, but their existence has never been firmly established. 

Robson s early work yielded some elegant examples of crystal engineering in which 3-D networks of simple, known structure types, such as the diamondoid and Re03 structures, were built from suitable combinations of metal ions and rigid linkers. Fig. 6 shows a simple example based upon the PtS structure.19 Others have exploited the same concept, including Carlucci el al.,20 who reported some remarkable open-frame-work structures based upon silver in combination with ligands such as pyrazine (Fig. 7). Some of the most striking examples... 

Studies of altered PT structure in schizophrenia have reported a reduced or reversed hemispheric asymmetry, or bilateral reductions in volume. Not all laboratories replicate these findings, and the literature is difficult to decipher because of the various methods used by different laboratories. The following discussion reviews these findings in the context of the different methods used. O Table 3.3-2 provides an overview of studies that used volume measurements. A more complete review of earlier studies that used length and surface area measurements is available elsewhere (Shapleske et al., 1999, 2001). 

The disulfides have pyrite (Ru3 and Os), distorted pyrite (Pd) and Cdl2 (Pt) structures all are diamagnetic. There are various mixed sulfides such as Ta2PdS6. 

Anisotropic bimetallic nanoparticles can also be synthesized by radiolysis. Indeed, /-irradiation of an aqueous solution containing silver and platinum metal ions and a polymer (PVA), at dose rates lower than 0.5 kGy.h , led to the synthesis of wire-like Ag-Pt structures with lengths up to 3.5 pm and diameters between 3 and 20 nm.ii7... 

Fig. 26. Temperature dependence of the splitting S of the satellites in the modulated PTS structure according to Ref. 95...

PTS structure 6.1), a and y will be nonzero but p will be zero because of inversion symmetry. For molecules such as p-nitroaniline and polymer chains such as isotactic polyphenylacrylate, P, as well as a and 7, is nonzero. 

PdO. In this structure also (which is that of PtS) the metal atoms form four coplanar bonds the coordination of 0 is tetrahedral (Fig. 12.4). As noted in Chapter 1 the bond angles represent a compromise between the ideal values of 90° and 109 ° due to purely geometrical factors. CuO has a less symmetrical variant of the PtS structure, and it is interesting that whereas CuO has the less symmetrical... 

Reaction barriers were determined from the TS structures. In agreement with many experimental findings, the activation energies are distinctly lower for palladium complexes than for the corresponding Pt structures the average difference is 9.7 kcal/mol, which indicates that the hydration processes are about 106 times faster in the palladium case. This is 1-2 orders of magnitude more than the values obtained from experimental data. 

Shimamoto, Y, Okamoto, T., Aono, H., Montanaro, L. and Sadaoka, Y, (2004) Deterioration phenomena of electrochemical CO2 sensor with PL Na2CO3/Na2O-Al2O3-4SiO2//YSZ/Pt structure. Sens. Actuators B, 99 (1-2), 141-8. 

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