Selective reduction of NO by CH4 in the presence of excess O2 has been studied on cobalt-ion-exchanged synthetic clinoptilolite (Co-CLI) zeolite. The catalytic results are compared with those obtained from Co-ZSM-5 and Co-FER, the two most widely studied catalysts for this reaction. At T ≥ 500 °C, Co-CLI is much more active for NO reduction than Co-ZSM-5, but it is less active than Co-FER. However, it is found that the selectivity for CH4 toward reacting with NO at high temperatures (T ≥ 450 °C) is higher on Co-CLI than on Co-ZSM-5 or Co-FER. On the basic of the overall catalytic results, the importance of zeolite pore size as a structural parameter influencing the activity of intrazeolitic Co2+ ions for NO reduction by CH4 is discussed.
Bibliographical noteFunding Information:
Support of this work was provided by the Korea Institute of Science and Technology (KIST). SBH thanks Drs. S.W. Nam and S.A. Hong of KIST for the use of their CO2 gas analyzer.
- NO reduction
- Synthetic clinoptilolite
- Zeolite pore structure