Surface species INDEX

KfAn) Index of the first surface species in surface phase n ... 

Absolute entropy, 51 Absorption edge, 351 Activated carbon, 710-713 adsorption of metal cations on, 712, 713 de-ashed, 713 heteroelenients in, 711 lEP and PZC of, 711, 712 reductive adsorption on, 711 Activation, 710 energy, 532 Activity, 50 coefficient, 588, 589 of surface species, 591 Adhesion method, 84 Adsolubilization, 494 Adsorbates, index of, 356-358, 428 32, 476, 477 Adsorption capacity, 581 competition, 510-530 dynamic studies, 335 edge, 328 envelope, 328 isotherm, 327... 

Subscript i identifies species, and J is a dummy index all summations are over all species. Note that Xp however, when i = J, then Xu = = 1. In these equations / (a relative molecular volume) and (a relative molecular surface area) are pure-species parameters. The influence of temperature on g enters through the interaction parameters Xp of Eq. (4-261), which are temperature dependent ... 

In situ Fourier transform infrared and in situ infrared reflection spectroscopies have been used to study the electrical double layer structure and adsorption of various species at low-index single-crystal faces of Au, Pt, and other electrodes.206"210 It has been shown that if the ions in the solution have vibrational bands, it is possible to relate their excess density to the experimentally observed surface. 

Since oxidation of methanol is an electrocatalytic reaction with different adsorption steps, interactions of the adsorbed species with the metallic surface are important. Using platinum single-crystal electrodes, it has been proven that the electrooxidation of methanol is a surface-sensitive reaction. The initial activity of the Pt(llO) plane is much higher than that of the other low-index planes, but the poisoning phenomenon is so rapid that it causes a fast decrease in the current densities. The... 

K being the leaf-spring constant) and by starting measurements with the surfaces far apart, where F(D) = 0, force profiles may be determined. The method also allows the measurement of the mean refractive index n(D) of the medium between the surfaces (9), and from this the amount r of adsorbed species per unit area of mica may be evaluated. Finally the mean radius of curvature R of the cylindrically curved mica surfaces near the contact area may also be calculated from the shape of the interference fringes. 

The surface concentrations T depend on the thickness of the interfacial region, and we would like to express them through quantities which are independent of it. This can be done for those species which occur both at the interface and in the solution. Usually one of the components of the solution, the solvent, has a much higher concentration then the others. We denote it by the index 0 , and introduce surface excesses with respect to the solvent in the following way In the bulk of the solution the Gibbs-Duhem equation (at constant T and p) is simply E Ni dfri = 0, or ... 

---