Single crystals, oxides, surface definition

The correct pzc of single-crystal faces of Cu was obtained576,578,587 only after a really oxide-free surface was produced, although unsuccessful attempts are still reported.597 The pzc values for the three main faces of Cu show the correct sequence with the crystallographic orientation, i.e., (Ill) >(100) >(110). These three values are still insufficient, however, to give definite evidence in a plot such as Fig. 12 of the characteristic pattern of the dependence on the crystallographic orientation. 

A. The Use of HRTEM and Scanning Electron Microscopy to Investigate the Morphology of Oxides and Chlorides Comparison of the Surface Definition of Dispersed Materials, Films, and Single Crystals... 

A variety of model catalysts have been employed we start with the simplest. Single-crystal surfaces of noble metals (platinum, rhodium, palladium, etc.) or oxides are structurally the best defined and the most homogeneous substrates, and the structural definition is beneficial both to experimentalists and theorists. Low-energy electron diffraction (LEED) facilitated the discovery of the relaxation and reconstruction of clean surfaces and the formation of ordered overlayers of adsorbed molecules (3,28-32). The combined application of LEED, Auger electron spectroscopy (AES), temperature-programmed desorption (TPD), field emission microscopy (FEM), X-ray and UV-photoelectron spectroscopy (XPS, UPS), IR reflection... 

In the in-situ electrochemical STM and electrochemical AFM investigations the first steps of the cyclovoltammetric formation of PPy could be seen. The polymer formed nuclei at a definite distance firom steps on the HOPG working electrode surface (Fig. 1). This can be interpreted as follows. Pyrrole monomers are oxidized at the most reactive centers on the WE surface such as steps and the defect sites of the single crystal surfiice. These oxidized pyrrole... 

Some problems, such as the determination of the support sites adopted by organometallics, may be tackled definitively only by recourse to single crystal surface science techniques. Many electron spectroscopies are inappropriate to the study of metal species on insulating or semiconductor supports. Recent results using specular reflectance FTIR and SEXAFS techniques, however, are encouraging and may be applied to oxide surfaces. These experiments also give data which can be directly compared with results obtained on high-surface-area supports and therefore provide a fruitful interrelationship. 

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