#2 Transmission, Reactor
An infrared cell is used for transmission infrared characterization of powder samples. The samples are pressed into pellets and held in the path of the infrared beam of a Bruker Tensor 27 FT-IR interferometer by placing them in a gas cell limited by two sealing NaCl windows. The temperature of the cell is monitored by a thermocouple placed in a thin tube close to the sample, and can be varied between –140 and 600 °C by using a combination of liquid nitrogen cooling and electric heating. A gas-handling system is used to pump this cell down to a few mTorr and to fill it with atmospheric pressures of the desired gases. The gas handling system can also be connected to a micro-batch reactor ("Hector"), which consists of a stainless-steel loop of 0.20 liters total volume connected to a recirculation pump for continuous gas mixing, a MKS Baratron vacuum gauge for gas pressure measurements, and a gas inlet manifold. The reactor loop is connected to a gas chromatograph for gas analysis (used to follow the kinetics of catalytic reactions), and also has a provision for attaching a detachable glass U-tube for the study of supported catalysts and for gas trapping when further gas sample analysis is required.
Techniques: Transmission IR, catalytic kinetics