Crystalline meso-/macroporous magnesium oxide prepared by a nanocasting route

Abstract

Porous magnesium oxide with a cellular macrostructure has been successfully prepared by a double replication route. In the first step, the synthesis of micro-/macroporous carbon monoliths was realized through a nanocasting approach using micro-/meso-/macroporous silica with a fully connected hierarchical pore structure as the template. In the second replication step the hierarchically organized porous carbon was converted into magnesium oxide by infiltration of the pore network with an aqueous magnesium nitrate solution and subsequent heat treatment at 300 °C to convert the nitrate into the oxide. Finally, the carbon template was removed by thermal combustion and (periclase) MgO with a cellular, very unique network build-up from interconnected, crystalline magnesia struts is obtained. The synthesis of periclase with high specific surface areas and a defined macroporosity paves the path to broaden the areas of applications for MgO.