Carbon gels with tuned properties for catalysis and energy storage

Mesoporous carbon materials are required for many applications, in order to avoid the diffusional limitations that occur with conventional activated carbons when processing large molecules or ions. The most rewarding approaches for the synthesis of mesoporous carbons involve sol–gel chemistry or the use of templates. Thus, carbon gels are obtained by polymerization of hydroxybenzenes and aldehydes by sol–gel processing, while ordered mesoporous carbons can be obtained from the same precursors in the presence of templates. In both cases, the textural properties of these nanostructured carbons can be easily adjusted by adequate selection of the synthesis variables. Their surface chemical properties can be modified by doping with heteroatoms and functionalization with surface groups. This can be done during the synthesis, or by subsequent treatments. The possibility of tuning both the texture and the surface chemistry is essential for the development of high-performance carbon materials that meet the requirements of the targeted applications. Recent advances and challenges related to the preparation of nanostructured carbon gels will be reviewed, together with relevant examples of their application in catalysis and energy storage.