IR Spectroelectrochemistry. Instrumentation and Applications of External Reflection, ATR, and Transmission Sampling.

This chapter illustrates the instrumentation and applications of external refl{ligature}ection, attenuated total internal reflection (ATR), and transmission sampling in IR spectroelectrochemistry. Infrared spectroscopy is an important technique which helps in the study of adsorption and catalysis at electrode-solution interfaces. Infrared radiation is focused onto the surface of the working electrode and light refl{ligature}ected by the electrode is collected and imaged onto an infrared detector. The electrode is positioned in a thin layer electrochemical cell adjacent to an infrared transparent window. At the electrode, the incoming and refl{ligature}ected beams interfere to create a standing electro-magnetic wave at the surface. ATR methods are useful for sampling in infrared spectroelectrochemistry. The working electrode consists of a thin metal fi{ligature}lm deposited on the fl{ligature}at face of the cell window. The strong electric fi{ligature}elds lead to an increase in the absorption strength of oscillators present at the metal-solution interface.