A hierarchically porous catalytic monolith prepared from a Pickering high internal phase emulsion stabilized by microporous organic polymer particles

Abstract A hierarchically porous catalytic monolith was fabricated from an oil-in-water Pickering high internal phase emulsion (HIPE) stabilized by the Ag-incorporated melamine-based microporous organic polymer (m-MOP/Ag) particles. The m-MOP/Ag particles were synthesized by polycondensation of melamine and 2-thenaldehyde, followed by in situ reduction of silver nitrate with NaBH4. A polyHIPE was obtained as a monolith by polymerizing acrylamide dissolved in the continuous phase of the HIPE. The monolith had a hierarchically porous structure, where the m-MOP particles possessing micro- and mesopores were embedded on the surface of interconnected macropores. Owing to its water wettability and hierarchical porosity, the catalytic monolith was successfully used for the reduction reaction of 4-nitrophenol in an aqueous medium.