FTIR spectrometer@Charles University for In Situ and Operando Surface Characterisation
Starting in 2027, a new FTIR spectrometer platform will expand the capabilities of the Czech CERIC-ERIC partner facility.
The proposed FTIR spectrometr will expand the capabilities of the Czech CERIC-ERIC partner facility, starting in 2027, by introducing three complementary techniques: Polarisation Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and Attenuated Total Reflection FTIR (ATR-FTIR). The integrated infrared spectroscopy platform is built based on Bruker VERTEX 80v Fourier-Transform Infrared Spectrometer (FTIR). The FTIR spectrometer covers a spectral range of 8000–350 cm-1, with a spectral resolution of 0.2 cm-1, and has fully evacuated optics operating below 0.2 hPa. The platform is integrated with the existing Near-Ambient-Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) system, enabling correlated characterisation of surfaces and materials through their chemical composition, electronic structure, and molecular vibrational fingerprints.
The PM-IRRAS measurements can be performed in a dedicated ultrahigh-vacuum chamber with a base pressure of 5 × 10-10 mbar, optically coupled to the FTIR spectrometer. The system allows controlled gas atmospheres at pressures of up to 1 mbar and sample temperatures ranging from 150 to 873 K. Infrared spectra are acquired using a highly sensitive liquid-nitrogen-cooled mercury cadmium telluride (MCT) detector, with a spectral range of at least 8000–850 cm-1 and a photoelastic modulator (PEM) operating at a frequency of at least 42 kHz. A key advantage is the vacuum-connected sample transfer between the NAP-XPS and PM-IRRAS chambers without air exposure, and the compatibility of the sample holders, which allows the same samples and surface states to be investigated using complementary techniques.
The DRIFTS module will enable measurements of powder and other diffusely reflecting samples, both with and without a reaction cell. The measurements can be made in the FTIR compartment after the DRIFTS module is installed. The module allows the incorporation of an additional high-pressure cell (Praying Mantis™ High Temp. Reaction Chamber). The high-pressure reaction chamber supports controlled atmospheres over a pressure range of 10-6–1000 mbar and temperatures from 25 to 700 °C, with programmable temperature control synchronised with spectral acquisition.
The ATR-FTIR module uses a fixed, unglued diamond crystal and a spectral range of 350–8000 cm-1, allowing measurements under vacuum, including analysis of powder samples using a pressure tip. As with DRIFTS, ATR measurements can be performed in the FTIR compartment after the ATR module is installed.
The platform can support investigations of adsorption, catalyst activation, oxidation and reduction, reaction intermediates, and surface reaction mechanisms under controlled and near-operando conditions. PM-IRRAS is particularly suitable for well-defined model surfaces and thin films, while DRIFTS and ATR-FTIR can extend the available measurements to powders and other materials. The integration of these infrared techniques with NAP-XPS, including air-free sample transfer and complementary measurements on the same sample, will provide CERIC-ERIC users with a distinctive multimodal research capability for correlating surface chemical states and electronic structure with molecular vibrations and reaction mechanisms. This strengthen the Czech PFy’s research potential in surface science, heterogeneous catalysis, energy conversion, and gas–solid interactions.