Back to homepage utwente.nl
Concentration management and in-situ tools in liquid phase heterogeneous catalysis
The application of solid catalysts in liquid phase reactions becomes increasingly important because of the easy separation of catalyst and products. One of the problems, however, with this type of reactions is the transport of reactants to the active surface (mass transport limitations). Due to mass transport limitations observed reaction rates are lower than the chemical reaction rate, thus lowering reaction rates. Even more important is the fact that very often selectivity is decreased as well due to consecutive reactions to unwanted products. |
|
At CPM new combinations of catalyst-reactor systems are developed that limit or prevent transport problems. Carbon fibres attached to structured catalyst supports, such as monoliths and metal foams, are a promising alternative for application of heterogeneous catalysis in liquid phase. The fibres create a “hairy” layer on the macrostructure thus increasing porosity and surface area. Further, carbon fibres are mechanically strong and chemically inert against acid and alkaline liquids, and can be easily used as support for catalytic active phases such as palladium or platinum.
The same type of materials is also being explored for application in micro-reactors and micro-channels, which eventually will lead to catalytic devices.
In addition, in-situ characterization techniques and tools for transient operation are being developed for application in liquid phase. Our general scientific knowledge on catalytic surfaces immersed in liquid phase is very much limited because of lacking experimental techniques. The technological quest to prevent diffusion limitations is also very relevant in this work in order to become able to connect spectroscopic information to reaction conditions applied.
