Pore structure alteration of porous carbon by catalytic coke deposition Original Research Article

The feasibility of preparing Carbon Molecular Sieve (CMS) by tailoring pore structure of activated carbon under catalytic cracking of benzene has been examined. In this method, benzene vapour was cracked over metal-impregnated activated carbon particles at 523–773 K. Among the metal catalysts tested, only cobalt exhibited significant cracking activity toward benzene. In this range of temperature coke was originated on the metal surface only, therefore an excessive coke deposition as indicated in non-catalytic process was not observed. The amount of coke and the site of deposition in the pore network were determined to some extent by the metal loading as well as the rate of benzene cracking. Raman spectra indicated that the coke produced was less amorphous than those produced in non-catalytic processes. Only a small loss in micropore volume and surface area was observed after the coke deposition process. The CMS produced was tested for its adsorption characteristics of carbon dioxide and methane. The improvement in the CO2/CH4 kinetic selectivity was observed.