The invention relates generally to hierarchical inorganic materials and a method for making and using same. The materials of the invention have a controlled hardness, porosity, and surface area ideally suited for use as, e.g., durable catalyst supports for reactions conducted in severe and/or hydrothermal environments. The materials of the invention are prepared by infusing hierarchical templates of suitably shaped sized cellulosic or lignocellulosic particles (e.g., from wood, bamboo, and the like) with soluble transition-metal and/or ceramic precursors. Infused templates are heated in a gaseous atmosphere until volatile chemical components are removed. After drying, the infused templates are heated under flowing argon, helium, or air atmosphere for several hours to remove volatiles and convert all or part of the transition-metal and/or ceramic precursors to respective carbide, oxycarbide, or other chemical forms.