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Clavilier method

Clavilier method for crystal preparation and flame annealing has been improved since 1980 and is employed as a standard procedure for singlecrystal electrode experiments using Pt, Pt metals, and Au. [Pg.184]

Polycrystalline gold and platinum electrodes can be converted into clean, well-ordered single-crystal electrodes by heating the respective wires in an Hj h- O2 flame. This is the so-called Clavilier method (134-137). Such electrodes are prepared by melting one end of a pure wire (1 mm diameter)—a zone-refining process. The crystallinity of the bead is usually... [Pg.146]

In the 1970s and 1980s the major trend was to study the electrooxidation reaction mechanisms and elucidate the surface adsorbed species acting as intermediates and/or catalytic poisons. This was facilitated by progress in experimental apparatus (e.g., development of methods for electrode potential-dependent analysis of surface and bulk intermediates and reaction products) and introduction of new techniques for easy preparation of clean single crystal electrodes (i.e., the Clavilier method [19]). [Pg.166]

The piezoelectric method should be noted as another technique for measuring the pzc. Introduced by Clavilier and Huong,213 and used by Bard et a/.,214 215 the piezoelectric method has been used more recently by Seo etal 16 and Dickinson etal.211... [Pg.42]

Some measurements with Pt single-crystal faces have been published recently.140,210,773 Iwasita and Xia210 prepared platinum single crystals according to the method of Clavilier et a/.186 773 After flame annealing and cooling in an H2 + Ar mixture, the electrode was protected... [Pg.133]

Kolb, reconstruction of, 85 Gold-solution interface (Clavilier and Nguyen Van Huong), 77 Guidelli, and the methods for the determination of the potential of zero charge, 63... [Pg.633]

Prior to the publication in 1980 of Clavilier s historic paper (1) reporting anomalous voltammetry of Pt(lll), there had been a number of studies of the voltammetry of single crystal Pt electrodes, with some using modern methods of surface analysis (e.g., LEED or RHEED) for characterization of the structure of the crystal prior to immersion in electrolyte (2-6). and all were in qualitative agreement with the seminal work (in 1965) on Pt single crystals by Will (7.). [Pg.37]

In contrast to the successful implementation of the bead method in studying the anomalous features, the contributions from studies with UHV-electrochemical systems has been limited to just a few. Subsequent work from our apparatus following corroboration of Clavilier s results concentrated on the effect of potential cycling through "oxide formation potential on the surface structure (19). and later on the effect of pH and type of anion (Wagner, F.T. Ross, P.N., J. Electroanal. Chem.. in press) on the anomalous features. Using the system in Yeager s laboratory, Hanson (20) was able to reproduced Clavilier s voltammetry not only for the (111) surface, but also the (100) and (110) surfaces as well. In spite of the relatively small number of contributions to the literature that have come from the UHV-electrochemical systems, they have made and essential validation of the bead method of surface preparation, and have verified the structure sensitivity of the anomalous features inferred from purely electrochemical observations. [Pg.40]

Clavilier s currently recommended procedure is as follows. Two cooling processes of the crystal after flame-annealing treatment are carried out between steps (a) and (b) in Fig. 1 i.e., air cooling until the temperature of the crystal becomes 200-300°C and cooling in pure water under an H2 -I- Ar stream. The transfer of the crystal into the cell in step (c) of Fig. 1 with a droplet of H2 + Ar-saturated pure water on the crystal face is important for protecting the crystal surface from impurities in air. Then the crystal surface is exposed to the solution by the dipping method of Fig. 1. [Pg.184]

FIGURE 1.10 Current intensity versus electrode potential voltammetric profile for platinum single crystals, Pt(100) (cooled in air) with blue lines, Pt(110) with black lines and Pt(lll) in red lines, in 0.5 M sulfuric acid solution run at 0.05 V s 1 at room temperature. A difference with respect to the early single crystal preparation method by Will [18] is that the ones reported here are those obtained by Clavilier early in 1980. After 50 years of the first paper by Will on the use of single crystals for the oxygen electroreduction reaction and his finding of the given preferred activities on (111) and (100) planes, the industry still uses polycrystalline surfaces. [Pg.15]

The Au(l 11) is often employed in air and ECSTM due to its inertness. The Au(l 11) can be prepared as a thin film grown on mica or glass.Gold beads can also be used as substrates. They are formed by melting the end of a wire on a torch following the method of Clavilier. The beads present flat areas suitable for molecular adsorption. The Au surfaces are cleaned by thermal annealing in a flame before molecular adsorption. When well prepared, the Au(lll) surface presents a reconstruction known as 22 xJ3. This structure is characterized by a pair of dislocation lines and is sometimes preserved upon molecular adsorption. Other compounds promote the lifting of the reconstruction. The other low Miller index faces of Au. namely, Au(l 10) and Au(lOO), normally employed as monocrystals, were also studied. [Pg.1203]

Flame-annealing and Quenching Method A unique and very convenient way to expose well-defined clean Pt into aqueous solution was proposed by Clavilier in 1980, in which mechanically exposed... [Pg.6555]

The experimental procedures specific to the UHV-EC [7] and STM-EC [5c,8] investigations have been described in detail elsewhere. UHV-EC work, carried out at Texas A M University (College Station, TX) employed a commercially oriented and metallographically polished, 99.9999%-pure Pd(llO) single-crystal electrode. STM-EC studies, undertaken at Tehoku University (Sendai, Japan) were done with Pd(llO) single-crystal surfaces prepared from 99.995%-pure polyciystalline Pd wires by the method of Clavilier [3] modified to compensate for the imique chemical properties of Pd metal. Commercial instruments were used in the UHV-EC (Perkin-Elmer, Eden Prairie, MN) and STM-EC (Digital Instruments, Santa Barbara, CA) experiments. [Pg.275]


See other pages where Clavilier method is mentioned: [Pg.182]    [Pg.183]    [Pg.189]    [Pg.189]    [Pg.277]    [Pg.268]    [Pg.6211]    [Pg.182]    [Pg.183]    [Pg.189]    [Pg.189]    [Pg.277]    [Pg.268]    [Pg.6211]    [Pg.39]    [Pg.531]    [Pg.210]    [Pg.413]    [Pg.40]    [Pg.485]    [Pg.41]    [Pg.13]    [Pg.182]    [Pg.92]    [Pg.236]    [Pg.114]    [Pg.838]    [Pg.6211]    [Pg.185]    [Pg.166]    [Pg.352]    [Pg.305]    [Pg.702]    [Pg.704]   
See also in sourсe #XX -- [ Pg.268 ]




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