The interface between Au(100) and 1-butyl-3-methyl-imidazolium-hexafluorophosphate.

The electrochemical interface of Au(100) and 1-butyl-3-methyl-imidazolium hexafluorophosphate has been characterized by cyclic voltammetry, electrochemical impedance spectroscopy and in situ STM, especially in two distinct potential ranges. In the vicinity of the potential of zero total charge--the value of which has been determined by immersion experiments--charging of the double layer is rather slow, it appears as if the ions comprising the ionic liquid would slowly exchange each other at the surface. In the other, very negative region the ordering of the cations has been observed by STM.

Impact of surface mechanics on the reactivity of electrodes.

Theory links the reactivity of metal surfaces to the interatomic spacing and, hence, to the tangential strain. We point out that this proposition can be experimentally verified by exploiting a seemingly unrelated phenomenon, the mechanical deformation of solid bodies when charged in an electrolyte. Such experiments allow the strength of coupling between adsorption enthalpy and strain to be quantified. For hydrogen adsorption on Pd, the result agrees with ab initio computation and with trends that can be inferred from experiment on pseudomorphic layers strained by epitaxy with misfitting substrates. The data suggest that experimentally accessible strain values afford a variation of the adatom concentration by several orders of magnitude and a significant shift of the reaction along the 'volcano curve' of reactivity versus adsorption strength.

Surface stress-charge response of a (111)-textured gold electrode under conditions of weak ion adsorption.

We report a cantilever bending investigation into the variation of surface stress, f, with surface charge density, q, for (111)-textured thin films of gold in aqueous NaF and HClO 4. The graphs of f(q) are highly linear, and the surface stress-charge coefficients, d f/d q, are -1.95 V for 7 mM NaF and -2.0 V for 10 mM HClO 4 near the potential of zero charge. These values exceed some previously published experimental data by a factor of 2, but they agree with recent ab initio calculations of the surface stress-charge response of gold in vacuum.

Unique activity of Pd monomers: hydrogen evolution at AuPd(111) surface alloys.

Well-defined Au/Pd(111) alloy films have been prepared on a Ru(0001) substrate by electrochemical metal deposition and subsequent heating up to 700 degrees C. The electrochemical behaviour of the 20 monolayers thick epitaxially-grown films is in excellent agreement with both equilibrium surface composition and distribution for Au/Pd alloys on Mo(110) as previously reported (D. W. Goodman et al., J. Phys. Chem., 2005, B109, 18535). The electrocatalytic activity of the AuPd(111) surface alloys was studied for the hydrogen evolution in 0.1 M H(2)SO(4) as a function of surface composition. Maximum activities were found for Pd fractions of 0.2 +/- 0.1, where the population of Pd atoms surrounded by Au has its maximum. These Pd monomers are found to be about 20 times more active than Pd atoms in the Pd overlayer.

Initial corrosion observed on the atomic scale.

Corrosion destroys more than three per cent of the world's GDP. Recently, the electrochemical decomposition of metal alloys has been more productively harnessed to produce porous materials with diverse technological potential. High-resolution insight into structure formation during electrocorrosion is a prerequisite for an atomistic understanding and control of such electrochemical surface processes. Here we report atomic-scale observations of the initial stages of corrosion of a Cu3Au111 single crystal alloy within a sulphuric acid solution. We monitor, by in situ X-ray diffraction with picometre-scale resolution, the structure and chemical composition of the electrolyte/alloy interface as the material decomposes. We reveal the microscopic structural changes associated with a general passivation phenomenon of which the origin has been hitherto unclear. We observe the formation of a gold-enriched single-crystal layer that is two to three monolayers thick, and has an unexpected inverted (CBA-) stacking sequence. At higher potentials, we find that this protective passivation layer dewets and pure gold islands are formed; such structures form the templates for the growth of nanoporous metals. Our experiments are carried out on a model single-crystal system. However, the insights should equally apply within a crystalline grain of an associated polycrystalline electrode fabricated from many other alloys exhibiting a large difference in the standard potential of their constituents, such as stainless steel (see ref. 5 for example) or alloys used for marine applications, such as CuZn or CuAl.

The electrochemical characterisation of benzyl mercaptan-modified Au(111): structure and copper deposition.

The behaviour of benzyl mercaptan self-assembled monolayers on Au(111) in sulfuric acid solution was studied using cyclic voltammetry and in situ scanning tunnelling microscopy. Modification of the Au(111) surface in an ethanolic solution of benzyl mercaptan leads to a disordered monolayer. However, by partial reductive desorption a striped c (15 x sqrt [3]) and a (2 x sqrt [3]) structure were obtained. The disordered benzyl mercaptan film was also used for the study of copper deposition. At -0.02 V versus SCE, that is in the underpotential deposition region, monoatomic high islands appear on the surface. Bulk deposition of copper starts at -0.08 V versus SCE with the growth of dendrites underneath the thiol film. At higher overpotentials, the growth of three-dimensional copper clusters commences.

Breakthrough bargaining.

Unspoken, subtle parts of a bargaining process--also known as the shadow negotiation--can set the tone for a successful negotiation. Deborah Kolb and Judith Williams, whose book The Shadow Negotiation was the starting point for this article, say there are three strategies businesspeople can use to guide these hidden interactions. Power moves are used when two negotiating parties hold unequal power--for instance, subordinates and bosses; new and existing employees; and people of different races, ages, or genders. These strategies, such as casting the status quo in an unfavorable light, can help parties realize that they must negotiate: they will be better off if they do and worse off if they don't. Process moves affect how negotiation issues are received by both sides in the process, even though they do not address substantive issues. Working outside of the actual bargaining process, one party can suggest ideas or marshal support that can shape the agenda and influence how others view the negotiation. Appreciative moves alter the tone or atmosphere so that a more collaborative exchange is possible. They shift the dynamics of the shadow negotiation away from the adversarial--helping parties to save face--and thus build trust and encourage dialogue. These strategic moves don't guarantee that all bargainers will walk away winners, but they help to get stalled negotiations moving--out of the dark of unspoken power plays and into the light of true dialogue.