介孔氧化锰对甲醛的低温催化氧化

摘要

采用硬模板法合成了介孔氧化锰纳米材料,考察了甲醛浓度对甲醛的催化氧化活性的影响.通过X射线衍射(XRD)、透射电镜(TEM)、高分辨透射电镜(HRTEM)等分析手段对合成的介孔材料进行了表征.结果显示,所合成的氧化锰具有很好的有序三维介孔结构,对甲醛具有优异的催化性能.甲醛的初始浓度对催化剂的活性有很大的影响,随着初始浓度的降低,催化剂活性逐渐提高.当甲醛的初始浓度为30 mg/L时,氧化锰催化剂在40℃时即可将甲醛完全降解.对于非贵金属型甲醛降解催化剂,此温度属于较低的.氧化锰优异的催化活性可能与其有序的介孔结构有很大的关系.%Mesoporous manganese oxide (Mn2O3) catalysts were prepared by a hard-template method.The as-prepared Mn2O3 catalyst was systematically characterized by XRD,TEM and HRTEM analyses.The results indicated that manganese oxide possess well-ordered mesoporous architecture with polycrystalline pore walls.Results of catalytic tests revealed that mesoporous manganese oxide showed excellent low-temperature catalytic activity for formaldehyde.The catalytic activities of the as-prepared materials are obviously affected by the concentration of formaldehyde (HCHO),which gradually increased with the decreasing of formaldehyde concentration.With a formaldehyde concentration of 30 rag/L,the temperature for 100％ formaldehyde conversion can be as low as 40 ℃,which is much lower than that ever reported over those noble-metal-free mesoporous catalysts.The superior catalytic performance of the mesoporous manganese oxide catalyst is attributed to the highly ordered mesoporous structure.