Spatially resolved in situ FTIR analysis of CO adsorption and reaction on Pt/SiO2 in a silicon microreactor

The design, fabrication and testing of a microreactor-FTIR imaging system is shown and used for the first time to demonstrate the ability to obtain in situ transmission FTIR analysis of working catalysts with both spatial and temporal resolution. MEMS (MicroElectroMechanical Systems) and microfabrication technologies were used to design and fabricate a microreactor with geometric and optical properties ideal for coupling with a high-throughput transmission FPA-FTIR system. CO adsorption and oxidation on Pt/SiO2 were used as a model catalyst system. Propagation of adsorbed species down the length of the microreactor was observed and fractional coverages were quantified during pulsed chemisorption experiments. The amount of adsorbed CO was also differentiated at different positions in the microreactor as a function of time during oxidation of the stored surface species.