| NOx is one of the main air pollutants. It is an important problem for people to effectively eliminate NOx under lean-burn conditions. This dissertation presents the synthesis of a novel type catalysts 12CaO·7Al2O3/x%M (M = K, Na, Mg) (C12A7/x%M) without noble metals, by using the microporous crystal material C12A7 sample . It is found that the C12A7/10%K catalyst possesses quite high NOx storage and NO reduction capacity. In this work we mainly focus on the NOx storage, NO reduction, sulfur tolerance, sample structure characteristics and the mechanism of the NOx storage-reduction of C12A7/10%K. Moreover, the NOx storage-reduction property on the perovskite type Ba-Zr-0 complex oxide catalyst is also investigated. The major conclusions have been summarized as follows:1. Study of the NOx storage capacity over a series of catalysts C12A7/x%MThe NOx storage capacity (NSC) of the C12A7/x%M catalyst mainly depends on the sample temperature, the M-doped amount, O2 and SO2 concentration in the mixture gases. It is found that the C12A7/10%K catalyst possesses the highest storage capacity and surfure tolerance among the C12A7/x%M catalysts. An optimum temperature window for the NOx storage over the C12A7/10%K catalyst ranges from 400 ℃ to 650 ℃, and reaches a maximum value of 183.9 μmol/g at about 550 ℃. The NSC of the C12A7/10%K catalyst increases with the increase of O2 concentration (0～4.8%) in the mixture gas. And no significant influence of SO2(0～150ppm) on itsNSC is observed.2. Investigation of the NO reduction property on the C12A7/10%K catalystThe NO reduction property on the C12A7/10%K catalyst mainly depends on the sample temperature, reducer and the composition in the mixture gases (e.g. the concentration of H2, O2, H2O and SO2 et. al.). The results indicate that the C12A7/10%K catalyst shows a good ability for NO reduction. When using H2 as the reducer, an optimum temperature windows for the NO reduction to N2 over...
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