Carbon spheres prepared from zeolite Beta beads

Porous carbon beads were prepared from macroporous anion-exchange resin beads preliminary converted into resin–zeolite Beta composite or pure zeolite Beta spheres. Two synthesis procedures were used depending on the initial template employed. In a series of experiments, the resin from the resin–zeolite Beta composite was directly carbonized into carbon. In another series of experiments, the resin was removed by oxidation at 600 °C leaving behind self-bonded zeolite Beta beads, which were filled with carbon by chemical vapor deposition (CVD) of propylene. As a final step for both procedures, the zeolite was dissolved in hydrofluoric acid. All the carbons prepared inherited the macroscopic spherical shape of the template spheres as well as the morphology of the primary particles building up the beads. The synthesis procedure and the carbonization temperature or the temperature for CVD of carbon employed influenced the ordering and the pore structure of the produced carbons. The carbons prepared by direct carbonization showed relatively low surface areas, less than 1000 m2 g−1, and no zeolite structural regularity. The samples obtained via CVD maintained the zeolite ordering with a periodicity of 11.7 Å and had surface areas of over 2000 m2 g−1.