High-surface area mesoporous carbons from gel templating and inorganic-organic hybrid gel formation

Mesoporous carbon materials with high surface areas and a high mesoporosity have been prepared using an interpenetrating inorganic-organic hybrid gel with hydrous alumina gel as soft template via two synthetic routes. In the single mix route, the hybrid gel was prepared with all the precursors are mixed at beginning, the inorganic alumina gel forms and then catalyzes the polymerization of a carbon precursor polymer. The final carbon product has the surface area over 1500 m²/g. In the alternative thixotropic mixing route, the hybrid gel was prepared by sequential but separate addition of inorganic and organic precursors. The alumina nanoparticles can reversibly self-assemble to form a three-dimensional gel network structure that ensures an open and connected network of the mesopores in the mesoporous carbon. The highest surface area was observed to be 1138 m²/g based on Brunauer-Emmett-Teller (BET) analysis on the N₂ sorption isotherms, while the mesopores have relatively uniform pore sizes around 5 nm in the Barrett-Joyner-Halenda (BJH) pore size distributions. Only 4% of the surface area was attributed to micropores for the high-surface area mesoporous carbons. Scanning electron microscopic studies reveal smooth surfaces without microscopic cracks in the material, indicating a macroscopic homogeneity of the materials.