Mixed metal oxide aerogels from tailor-made precursors

Abstract

Highly porous mixed oxides and metal-doped materials are relevant for many applications including filters, sorption media or photocatalysts, in medical, or electrochemical and optical applications, etc. Mixed oxides are of special interest for several reasons: the chemical properties of an otherwise “inert” support can be improved by the second component, i.e. comprising characteristics, such as higher acidity, larger surface areas, thermal stability, etc. However, the properties of the final material strongly depend on the chemical homogeneity or degree of demixing of the various components. The development of general, cost-effective routes allowing for the synthesis of such mixed metal oxides with deliberately designed structural features on all length scales (from the atomic level to the macroscopic morphology) is still a demanding task. In this paper, we will provide an overview over different solution-based chemical approaches, e.g. sol–gel processes, to highly porous (monolithic) mixed metal oxide aerogels.