| 초록 |
The selective catalytic reduction (SCR) of NO by methane (CH4-SCR : CH4 + O2 + 2NO → CO2 +2H2O + N2) is one of the aftertreatment technologies for the control of slipped methane and thermal NOx emitted from vehicles or stationary sources by natural gas combustion. Indium containing zeolites has been reported as promising catalyst formulation for the CH4-SCR reaction due to the intrinsic activity of In cations as an active sites. The reaction intermediate such as nitrate and nitrite formed by NO oxidation possibly play a role in the activation of methane on the active sites. In this study, we prepared the In-Pt/ZSM-5 catalysts for simultaneous CH4-NO reduction. The catalysts revealed further improvement of catalytic activity by the treatment with 10% H2 flow at 500 ℃. The enhanced CH4-SCR performance by the reduction treatment may be attributed to the increased amount of In cations and redispersion of Pt crystallites on the external surface into the ZSM-5 channels. In addition, a series of In-based ZSM-5 catalysts has been prepared by adding Ir or Co to compare the CH4-SCR activity. |
