A flow reactor system for catalytic reaction studies, allowing time‐ and space‐resolved measurements of gas composition and temperature around the catalyst

A flow reactor system for catalytic reaction studies is described. The system is equipped with a movable gas sampling device and on‐line mass spectrometry (MS), allowing time‐ and space‐resolved measurements of gas composition and temperature. Results from H2 oxidation on Pt are used to illustrate the system performance. Spatial variations of H2, O2, and H2O concentrations can be measured, e.g., during mass transport limited conditions. Temporal variations in H2, O2, and H2O during chemical oscillations are well resolved close to the catalyst, but successively smeared away at increasing distance. The special design of the gas sampling probe allows quantible MS measurement even of H2O and other ‘‘difficult’’ gases, and of gas temperature variations.