Patent ID: 9642394
Date: 2017-05-09
CPC Classifications: A24D,B01J

Claim:
1. A method of enhancing the selectivity of porous carbon for hydrogen cyanide (HCN), the method comprising: impregnating activated carbon with zinc salt, the impregnating including at least one of: (1) dip impregnation with an aqueous solution of zinc salt, the solvent consisting of water, (2) spraying with an aqueous solution of zinc salt, the solvent consisting of water, or (3) soaking with an aqueous solution of zinc salt, the solvent consisting of water; and thermally treating the impregnated activated carbon to form porous carbon impregnated with zinc oxide, wherein the activated carbon has at least 30% of the pore volume as micropores, and wherein, when used in a smoking article filter, the porous carbon has an enhanced selectivity for HCN relative to the activated carbon without impregnation with zinc oxide.