Europium-containing organic gels and organic and carbon aerogels. Preparation and initial applications in catalysis

We prepared organic gels and organic and carbon aerogels doped with europium through sol-gel processes. Eu-gels were prepared by sol-gel polymerization of the potassium salt of 2,4-dihydroxybenzoic acid with formaldehyde followed by ion-exchange with Eu(OTf)3. Eu-organic aerogels were obtained after CO2 supercritical drying of the gels and Eu-carbon aerogels were obtained by pyrolysing the organic aerogels. The Eu-gels containing 12% europium proved to be efficient as recoverable catalyst in Michael additions. © Springer-Verlag 2006.