Imaging Catalysis: Operando Investigation of the CO2 Hydrogenation Reaction Dynamics by Means of Infrared Thermography

Infrared thermography is a powerful tool to investigate the dynamic evolution of temperature in chemical reactions. The CO2 hydrogenation reaction is an ideal model reaction to assess the presented technique due to its high exothermicity. Various dynamic experiments are performed in a newly designed reaction cell with an infrared transmitting ZnSe window. In particular, the gas exchange reactions between CO2 and H2, the coinjection of the two reactants, and the study of the effect of inert gas addition are investigated. Here, we show that the reaction rate on the surface of a catalyst can be localized in time and space by means of infrared thermography. This opens the way to the precise description of reaction dynamics, in particular for reactions operating in intermitting conditions. Furthermore, we show that the combination of infrared thermography with other analytic techniques such as rapid and quantitative mass spectrometry enables a holistic understanding of the transient reaction phenomena.