Example of Carbon Monoliths as Catalyst Support Material

In this chapter two different catalytic systems with carbon monoliths as the support matrix are discussed in terms of preparation and performance. The main difference between these systems is the effect of the carbon monolith on selectivity. Finally, some practical considerations of the use of different carbon monoliths are discussed. 

6 EXAMPLE OF CARBON MONOLITHS AS CATALYST SUPPORT MATERIAL 

Enzymes are an attractive tool in asymmetric catalysis and efficiently complement traditional chemical methods [32,33]. The use of biocatalysts makes it possible to carry out chemical transformations without the need for laborious protection and deprotection steps [34]. Immobilized enzymes are preferred over free enzymes in solution, due to the possibility of repeated use, higher resistance to denaturing effects, and easy separation. The use of a structured support material could be an interesting alternative for conventional particulate enzyme carriers. When optimizing the use of immobilized enzymes, the immobilization method chosen is a very important factor to consider [35]. In this study, a reaction in an organic medium is considered most enzymes do not readily dissolve in organic media, and the enzyme will not detach from the support. This makes physical adsorption a very suitable technique to prepare a biocatalyst for use in an organic medium 

2 Selective Hydrogenation of D-Glucose Over Monolithic Ruthenium Catalysts 

In this study, the influence of dispersion and distribution of the active phase (rnthenium) and the accessibility and performance of the carbon-based monolithic strnctures have been evaluated in the hydrogenation of D-glucose. Special attention has been paid to the stabihty of the catalysts in successive hydrogenation rnns. Especially, fixed-bed catalysts (e.g., monoliths) require a maintained activity for long periods of time for successful application in industry. The performance of the monolithic reactor has been compared with slurry-phase operation. 

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