Imaging of Heterogeneously Catalyzed Reactions by Time-Resolved IR Thermography

An infrared thermography (IRT) chemical engineering experiment using a commercial thermal video camera for visualization of the dynamics of heterogeneously catalyzed reactions is described. The laboratory acquaints chemical engineering students with the IRT method and teaches them to analyze and interpret thermograms. As an illustration the imaging of the temporal patterns during CO oxidation over Pd supported on fiberglass-cloth catalyst is considered. This simple and important reaction is known to exhibit oscillatory behavior, often encountered in industrial and environmental chemistry where nonequilibrium conditions prevail. The laboratory experiment demonstrates that IRT not only provides temperature-mapping capability, but also allows real-time monitoring of the kinetics of the chemical reaction enabling the students to "see" the oscillating spatiotemporal patterns on the catalyst surface. IRT is an effective tool for assessing the rate of catalyzed reactions and can be employed in the discovery of single-active catalysts.