Synthesis of porous carbons from aromatic precursors on MgO under autogenic pressure in a closed reactor

Abstract

Undoped, N-doped, and S-doped porous carbons were prepared via the hard-template method by direct carbonization of aromatic precursors on MgO at 500 °C and autogenic pressure. The influence of aromatic precursors on the yield, morphology, structure, surface composition, and textural properties of the carbons was investigated. The side-chain and number of the benzene ring promoted the yield of carbon. Acenes produced more carbon among the polycyclic aromatic hydrocarbons. The highest yield of carbon was 52.9 wt% using pyrrole as precursor on a commercial sheet MgO. The size of micropores and macropores as well as nitrogen content was also dependent on the aromatics. Three types of MgO were compared using pyrrole as precursor. Morphology of MgO played a key role on the yield of porous carbon. The yield of carbon reached 50.5 wt% and the surface area of carbon was 671 m2 g−1 on a home-made MgO. After KOH activation, the surface area of the porous carbon increased dramatically to 2788 m2 g−1 and exhibited a high adsorption capacity up to 980.4 mg g−1 for methylene blue.