CaH_2对Cu-Ce-La-ZSM-5催化分解NO性能的影响

实验采用一步离子交换法制备Cu-Ce-La-ZSM-5催化剂,然后采用共混法制得Cu-Ce-La-ZSM-5/CaH2催化剂。采用扫描电镜(SEM),电感耦合等离子体发射光谱(ICP-AES),X射线衍射(XRD),红外(FTIR)以及NO吸脱附(NO-TPD)对催化剂进行表征。结果显示CaH2的加入使得催化剂中铜离子存在形式发生变化,催化剂表面变光滑洁净,并且吸附NO能力增强。NO催化分解实验的结果表明CaH2提高了催化剂活性和抗氧性。CaH2助催性是由于其受热分解过程中产生的H2能将Cu2+还原为具有催化活性的Cu+,同时使催化剂表面洁净光滑更容易吸附NO。

Impact of CaH2 on NO decomposition by Cu-Ce-La-ZSM-5

Cu-Ce-La-ZSM-5 catalyst was prepared by one-step ion exchanging. And then Cu-Ce-La-ZSM-5/CaH_2 was prepared by mixing calcium hydride and Cu-Ce-La-ZSM-5. The prepared catalysts were character-ized by scanning electron microscopy ( SEM) , atomic emission spectroscopy with inductively coupled plasma at-omization ( ICP-AES) , X-ray powder diffraction ( XRD) , fourier transform infrared spectroscopy ( FTIR) and tem-perature-programmed desorption of nitrogen oxide( NO-TPD). The results showed that the presence of CaH_2 re-duced the form of copper ion in catalysts. Furthermore Cu-Ce-La-ZSM-5/CaH_2 catalyst had smoother surface and showed stronger adsorption ability to NO. It could be concluded from catalytic tests that Cu-Ce-La-ZSM-5 \CaH_2 exhibited better resistance to oxygen and higher activity. CaH_2could improve the ability of Cu-Ce-La-ZSM-5 be-cause it could produce H_2 at higher temperatures. The produced H2 could deoxidize Cu~(2+) to Cu~+which was ac-tive in NO decomposition and increased the adsorption ability by smoothing the surface of catalysts.