煤系高岭土制备Fe-MCM-41介孔分子筛及其氨选择性催化还原NOx

以煤系高岭土、十六烷基三甲基溴化铵（CTAB）、硝酸铁等为原料，通过水热法合成不同Fe含量的六方介孔分子筛Fe-MCM-41。通过傅里叶变换红外光谱、N2吸附脱附、高分辨透射电子显微镜对催化剂进行表征，并以氨为还原剂研究其选择性催化还原NO活性以及反应条件（包括Fe掺量、反应温度、空速、氨氮比和O2浓度等）对催化性能的影响。结果表明，Fe成功进入MCM-41介孔材料的骨架内，Fe-MCM-41介孔分子筛BET比表面积为980.2～596.8 m2/g，孔容积为0.95～0.60 cm3/g，平均孔径在3.90～3.45 nm。随着铁掺杂量的增加，介孔结构的有序度下降。当n(Fe)/n(Si)=0.05、空速为5000 h?1，Fe-MCM-41催化剂在350 ℃反应时NO转化率最高，可达90.7%；且当氨氮比为1.1和O2含量为2.5%时，催化剂能保持较高的活性。

Preparation of Fe-MCM-41 mesoporous molecular sieves from coal-series kaolin and selective catalytic reduction of NO_x

Hexagonal Fe-MCM-41 mesoporous molecular sieves with different contents of iron were synthesized by the hydrothermal method from coal-series kaolin，cetyl trimethyl ammonium bromide and iron nitrate as raw materials. Fe-MCM-41 was characterized by Fourier Transform Infrared Spectroscopy (FTIR)，N2 adsorption and desorption isotherm plot methods and High Resolution Transmission Electron Microscopy (HRTEM). NO catalytic activity of selective catalytic reduction (SCR) with the prepared molecular sieves and ammonia as reductant under different conditions，such as dosage of Fe，temperature，space velocity，n(NH3)/n(NO) and O2 concentration were studied. The result indicated that Fe was introduced into the framework of MCM-41 mesoporous materials. BET specific surface area was in the range of 980.2～596.8 m2/g，pore volume was in the range of 0.95～0.60 cm3/g，and average pore diameter calculated by BJH method was in the range of 3.90～3.45 nm. Fe-MCM-41 with n(Fe)/n(Si)=0.05 had the highest catalytic activity at 350℃，and the highest NO conversion was 90.7% at a space velocity of 5000 h?1，n(NH3)/n(NO)=1.1 and O2%=2.5%.