Microfluidic Reactor for Spatially-Resolved Measurements of Catalytic Activity

An experimental system capable of performing spatially-resolved measurements of catalytic activity on surfaces with 1 mm resolution is presented. The system is primarily designed for multi-component thin film catalysts having a concentration gradient along one or two axes. At the center of the system is a multilayer glass microfluidic device that directs gas flows to and from the reactive surface. Reactant gas is simultaneously delivered to 10 reaction points on the surface arranged in a linear array with 1 mm spacing. After reaction, the gas is withdrawn along 10 different channels. Each of these channels can be connected to a QMS for mass-spectrometric analysis of the output. The performance of the system was tested using H₂-D₂ exchange reaction on Pt thin films with a thickness gradient. Expected activity variations across the surface were observed.