A versatile surface Raman spectroelectrochemical flow cell: applications to chemisorbate kinetics

A versatile spectroelectrochemical flow cell is described, with the objective of probing adsorption-desorption and other adsorbate rate processes triggered by alterations in the solute composition, as monitored by surface-enhanced Raman spectroscopy (SERS). The device offers flexibility in electrode replacement and pretreatment, and provides rapid (ca 1 s) changes in the solution composition in contact with the surface, enabling adsorbate rate processes down to this timescale to be accessed by means of temporal SERS sequences. Some illustrative applications are briefly outlined, exploiting the now-established broad-based applicability of SERS to transition-metal films as well as coinage-metal surfaces. These include non-reactive adsorbate substitution processes, and the use of isotopic substitution to explore dissociative adsorption triggered by reactive versus non-reactive desorption, specifically regarding the catalytic role of chemisorbed CO in formic acid electrooxidation on rhodium. (C) 2001 Elsevier Science B.V. All rights reserved.