IR-Spectroelectrochemistry combines IR spectroscopic measurements with electrochemical investigations.

For our studies we built a spectroelectrochemical cell (SEC cell), designed by Kubiak et al., which is used in external reflection mode. Here, a polished, disc-shaped working electrode made of platinum or glassy carbon undertakes the function as IR beam reflecting surface. The pseudo reference- and counter electrode are installed in form of wires made of silver and platinum, which are circularly arranged around the working electrode. A liquid sample is located in a small layer between the electrode surface and an IR-transparent window made of CaF₂.

The described spectroelectrochemical cell is mounted onto a Specac mirror reflection unit. The entire divice is coupled to a PalmSens potentiostat and installed into the BRUKER Vertex 80 spectrometer. The way of the IR beam is the following: Coming from the interferometer, the IR beam is reflected at the first mirror of the unit and passes through the CaF₂ window and the sample layer. It is further reflected at the working electrode. After passing the sample layer and CaF₂ window again, the IR beam is reflected for the last time at the second mirror of the unit and encounters the MCT-detector.

By application of rapid-scan-technology, the time resolution of the IR spectrometer lies within the millisecond range. In this manner, during typical electrochemical procedures like cyclovoltammetry, chemical changes of the sample as a function of the applied potential are detected by time resolved IR spectroscopy.

For preliminary studies we use an additional bulk electrochemistry setup with a working- and counterelectrode made of platinum, respectively, as well as a silver/silver nitrate reference electrode.