The process begins with the selection of a suitable hard template, which might be a solid structure such as silica, carbon, or a variety of other materials. The template is then impregnated with a precursor to the desired material, which is often an oxide or a metal. After the precursor fills the pores of the template, it undergoes a chemical transformation such as calcination or reduction. Finally, the template is removed by chemical etching or thermal decomposition, leaving behind the desired porous material.
