Decomposition of NO by Cu-impregnated ACFs

NO gas was decomposed by Cu-impregnated rayon based ACF in a column reactor at $300-400^{\circ}C$ in helium surrounding. Initial NO concentration was 1,300 ppm. The as received ACF adsorbed NO very little. However, NO was effectively decomposed by 5-10 wt% Cu-impregnated ACF at $400^{\circ}C$. The concentration of NO was maintained less than 200 ppm for 6 hours in this system. Copper was impregnated at the entrance of micropores. Impregnation of Cu particles on ACF should be homogeneously distributed to increase the capacity of catalytic reduction of NO. The Cu-impregnated ACF-C(Cu) deoxydized NO to $N_2$ and was reduced to $ACF-C(Cu_2O)$ in the initial stage. $ACF-C(Cu_2O)$ also deoxidized NO to $N_2$ and was reduced to ACF-C(CuO). There was little consumption of ACF in mass during the catalytic reduction of NO to $N_2$ by copper. The catalytic reduction was accerelated by increasing the reaction temperature.

구리첨착 ACF에 의한 NO의 분해

레이욘계 활성탄소섬유(KF-1500)에 구리를 첨착하고 반응관에 충전한 후 $300-400\;^{\circ}C$에서 NO가스를 통과시키면서 촉매분해시켰다. NO 가스의 주입농도는 1,300 ppm 이다. 구리를 첨착하지 않았을 때는 NO 가스를 거의 흡착하지 않았으나 구리를 5 혹은 10 wt% 첨착시킨 활성탄소섬유는 $400\;^{\circ}C$에서는 6시간 이상 200 ppm 미만의 NO 농도를 유지하면서 효과적으로 분해시켰다. 구리는 활성탄소섬유의 미세공 입구 탄소에 첨착되며, 활성탄소섬유에 첨착된 구리 [ACF-C(Cu)]는 반응의 초기에는 $[ACF-C(Cu_2O)]$가 되면서 NO를 $N_2$로 환원시켰다. $[ACF-C(Cu_2O)]$도 NO를 환원시켜 $N_2$를 발생시키면서 [ACF-C(CuO)]가 되었다. 이러한 반응이 진행되는 동안 활성탄소섬유의 질량은 거의 변함이 없었으므로 첨착된 구리가 촉매로 작용하였다고 판단되며, 촉매 환원의 반응온도가 높을수록 가속되었다.