Microfabricated components for heterogeneously catalysed reactions

Microsystems offer considerable industrial potential for unit operations, e.g. heat transfer, mass transport, and mixing of gases and liquids. The development of techniques for performing chemical reactions in microsystems has high priority. Only a few examples are known of using microreactors for performing homogeneous chemical reactions and heterogeneously catalysed liquid-phase enzyme reactions. However, heterogeneously catalysed gas-phase reactions in microreactors have not been reported at all. This is due to the lack of surfaces having enough catalytically active sites. The present article describes a method for treating the surfaces of channels in a microreactor in order to achieve adequate numbers of catalytically active and selective sites - which is the main prerequisite for the performance of heterogeneously catalysed reactions. The experimental procedure and the measurements of characteristic parameters are described. An envisaged scheme for a chemical microsystem similar to a chemical microplant is presented, and its scaling up via replication is addressed.