Carbons with a hierarchical porous structure through the pyrolysis of hypercrosslinked emulsion-templated polymers

Porous carbons with hierarchical porous structures that combine microporosity, mesoporosity, and macroporosity, should have more accessible porous infrastructures that would be advantageous for a range of "green" energy-storage applications. PolyHIPEs are porous polymers, templated within high internal phase emulsions (HIPEs), that can themselves be used as templates to generate porous carbons. This paper describes the generation of highly porous carbons with hierarchical porous structures through a relatively simple process, the pyrolysis of hypercrosslinked polyHIPEs based on vinylbenzyl chloride. The effects of the synthesis parameters, the hypercrosslinking conditions, and the pyrolysis conditions upon the porous structures and the properties are described. The combination of DVB-crosslinking with micropore-generating hypercrosslinking was used to preserve the hierarchical porous structures during pyrolysis. A highly porous carbon with a Brunauer-Emmett-Teller specific surface area of 553 m²/g, a porosity of 86.0%, and a hierarchical porous structure that included 10 μm macropores and 0.77 nm micropores was achieved.