M. Klotz et al./Ice Templating of MicromonolithsFig. 4. Macroporous YSZ ice templated monoliths (a) macroscopic view (b) SEM micrograph perpendicular to ice solidification direction, showing the macroporous channels (c) mercury porosimetry results (d) SEM micrograph along ice solidification direction (e) SEM micrograph of the monolith washcoated with boehmite (f) close-up view of the washcoat, the arrows indicates the thickness of the coating. Scale bars (b) 50 mm, (d) 20 mm, (e) 2 mm, and (f) 250 nm.

Alumina supports presenting a bimodal porosity are generally advantageous for the conversion of bulky molecules such as found in biomass, refining, and petrochemistry. However, shaping of such materials, while controlling pores size and orientation, proves to be hard. This problem can be tackled by using a simple method involving sol-gel chemistry, surfactant self-assembly, and ice-templating. Herein, a systematic study of the formulation and process parameters' influence on the final material properties is presented. This protocol results in the repeatable preparation of centimeter-sized alumina monoliths presenting a uni-directional macroporosity and structured mesopores. These monoliths should be of particular interest in high flow rate catalytic applications.