Abstract: A nanoporous aerogel comprising an acid-catalyzed, oxidatively aromatized PBO polymer. The nanoporous aerogel includes a benzoxazine moiety containing polybenzoxazine polymer with up-to six sites of cross-linking per unit is the product of the high yield, room temperature, and acid catalyzed synthesis method, as provided for herein. A method of producing the aerogel is providing that results in robust monoliths, oxidative aromatization, and conversion to nanoporous carbons for the provided aerogels. The PBO polymer may be co-generated as an interpenetrating network with a metal oxide network, wherein the PBO network serves as both a reactive template and as a sacrificial scaffold in the synthesis of the pure, nanoporous, monolithic metal aerogels, in an energy efficient method.