Rapid-scanning FT-IR spectrometers

Both dispersive monochrometers and Fourier Transform IR (FT-IR) spectrometers can be used in recording SEIRA spectra, but FT-IR spectrometers are more convenient owing to Fellgefs, Jacquino s, and Connees s advantages [128]. The time-resolution of FT-IR spectroscopy is determined by the scan rate of the interferometer. Tens to hundreds of milliseconds time-resolution can easily be achieved by the use of modern rapid-scan FT-IR spectrometers at spectral resolutions of 4 or 8 cm . ... 

The combination of the high sensitivity of SEIRAS and a rapid-scan FT-IR spectrometer enables the spectral collection simultaneously with electrochemical measurements such as cyclic voltammetry and potential-step chronoamperome-try. The time-resolved measurement can give some information on electrode kinetics and dynamics, as has been shown in Fig. 8.24. Figures 8.25 and 8.26 represent another example of millisecond time-resolved ATR-SEIRAS study of current oscillations during potentiostatic formic acid oxidation on a Pt electrode [123]. At a constant applied potential F of 1.1 V, the current oscillates as shown in Fig. 8.25 a. Synchronizing with the current oscillations, the band intensities of linear CO and formate oscillate as shown in Fig. 8.26 (and also in Fig. 8.25 c). 

The Bruker FT-IR imaging system (Bruker Optik GmbH, Ettlingen, Germany) used for the investigations described in this chapter is shown in Figure 8.3. The system consists of an IFS66/S step-scan/rapid-scan FT-IR spectrometer (left), which... 

An alternative technique for time-resolved infrared measurements on a rapidscanning FT-IR spectrometer that not only overcomes the limitations of stroboscopic spectroscopy described in Section 19.3 but under certain circumstances appears to have better time resolution than measurements made on a step-scan interferometer has been developed by Masutani et al. [22-25]. In this technique, the sample perturbation is not timed to coincide with the scanning and data acquisition of the spectrometer, (i.e., the two are asynchronous). The basic instrument used for asynchronous time-resolved FT-IR spectrometry is a standard rapid-scanning FT-IR spectrometer to which is added a boxcar integrator and some timing circuitry. The instrumental setup is shown in Figure 19.8. 

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