Electrochemical and surface enhanced Raman scattering studies of bromide ion adsorption at silver electrodes in a series of normal alcohols

Abstract

Br~surface coverage as a function of electrode potential is quantitatively determined using the HurwitzÈParsons analysis of di †erential capacitance data at Ag electrodes in the series of normal alcohols, methanol through pentanol, containing LiBr. Values for the potential of zero charge (pzc) are estimated from these data. Surface-enhanced Raman spectroscopy (SERS) data in the l(AgÈBr) region show the presence of a l(AgÈBr) feature at potentials positive of the pzc which supports strong speciÐc adsorption of Br~in these media. An excellent correlation between the SERS intensity and the Br~surface coverage determined from di †erential capacitance is observed. Bands attributed to hindered translational modes of trace interfacial water are also observed.

Electrocatalytic reduction of arylethyl chlorides at silver cathodes in the presence of carbon dioxide: Synthesis of 2-arylpropanoic acids

“…Nevertheless, it can be inferred from the observed electrocatalytic activity that surface phenomena such as adsorption and desorption of reagents, intermediates and products play an important role in the process. In fact, the high affinity of Ag for the halide ions, which are the products of the ET, is well documented in the literature [34][35][36][37]. Also reductive dehalogenation of alkyl halides at Ag(1 1 1) surfaces is a well-known process [38][39][40][41].…”

Investigation of trace interfacial water at silver electrodes in a series of normal alcohols using surface enhanced Raman scattering

“…Although this observation is not surprising based on the comparable water content of these alcohols, it is somewhat surprising in light of the Br~surface coverages estimated from di †erential capacitance measurements. 45 The maximum surface coverage values estimated indicate that in methanol, ethanol and propanol, the surface is not completely covered by a close-packed monolayer of Brw hereas in butanol and pentanol, a close-packed monolayer has been achieved at these potentials. Thus, either the A band water species are not necessarily in direct contact with the Ag surface or the di †erential capacitance measurements cannot distinguish between a surface Br~or a surface A band water molecule.…”