Fabrication of ceramic components with hierarchical porosity

This article reviews different methodologies for the fabrication of monolithic ceramic components possessing multiscale porosity, i.e., with pores ranging from a few nanometers to several hundred microns. Two main strategies have been discussed: (a) the assembling of micro/mesoporous materials into components possessing also macropores; (b) the addition of micro/mesoporosity to macroporous, cellular monoliths. Both routes include one-pot and multi-step processing routes, and yield components with different properties in terms, for instance, of specific surface area values, mechanical strength, and permeability to fluids. The wide range of processing approaches available enable the fabrication of components with very varied morphology, suitable for a variety of industrial applications.