Synthesis and applications of hierarchically porous metal and metal oxide monolithic materials
A nanocasting method for synthesizing a broad range of hierarchically porous, high surface area metal and metal oxide monolithic materials was developed. The importance of a well-connected hard template was established based on conductivity measurements. A hierarchically porous, silica monolith prepared with 7% ocadecyltrimethylammonium bromide was found to be the optimum silica template. Several different factors were found to regulate how well the silica template was replicated. When the connectivity of the silica template, contents of the metal salt solution, impregnation method, temperature, atmosphere, and template removal are all controlled, a good replica of the original silica monolith can be attained in different metals or metal oxides. These metal and metal oxide monoliths were used in catalysis and liquid chromatography.