Setup, sensitivity and application of thin electrolyte layer ATR-FTIR spectroscopy

A new setup of an attenuated total reflection-Fourier transform infrared (ATR-FTIR) method involving a thin electrolyte layer was developed for the in situ investigation of electrode processes. The applicability of the approach was tested in 0.5 M H2SO4 by studying the oxidation of adsorbed CO using polycrystalline Pt and Pt particles supported on high surface area carbon black. The sensitivity of this new ATR–FTIR method appears to be better than found for previously reported results obtained using external reflection–absorption FTIR. High sensitivity was obtained by making a very good contact between the electrode surface and the ATR crystal, which was achieved by using a spring, a micrometer and X- and Y-position controllers. This new thin electrolyte layer ATR-FTIR technique was also successfully applied to the in situ study of surface species adsorbed on an IR non-reflecting porous electrode.