双金属 MEL结构杂原子分子筛催化性能的研究

研究了 H2 O2 存在下双金属 Cr Co-、VCr-、VCo-、VNi-、Cr Ni MEL结构杂原子分子筛对环己醇、2 -丁醇、2 -丙醇、环己烯的选择氧化催化性能 ,并考察了反应温度及 H2 O2 浓度对环己烯催化氧化反应的影响 .结果表明 ,反应物不同 ,活性亦不同 ,其顺序为环己烯 >环己醇 >2 -丁醇 >2 -丙醇 ;Cr Ni-、Cr Co MEL分子筛活性较高 ,而 VCo-、VCr-、VNi MEL分子筛活性较低 .反应温度和 H2 O2

超细微MEL结构铜硅分子筛的合成及理化性质

Ultrafine coppersilicate with MEL structure has been hydrothermally synthesized for the first time under static conditions. By means of XRD, TEM, FTIR, ESR, TG\|DTA and NH 3 TPD the physicochemical property of this novel material was investigated. It was revealed that the as synthesized coppersilicate, which was a uniform, monophase and ultrafine nanomaterial with crystallite size less than 1×10 -8 m , was highly crystalline and thermal stable. Cupric ions were highly dispersed and mainly resided in distorted tetrahedral and square pyramidal environments in the as synthesized as well as the calcined coppersilicates. Incorporation of copper ions into the framework during crystallization also resulted in a weak acidity of this material. [WT5HZ]

微米级MEL分子筛聚集体的制备(英文)

使用四丁基氢氧化铵-正硅酸四乙酯-水(TBAOH-TEOS-H2O)简单体系一步水热制备了具有多级孔道的微米级MEL结构分子筛聚集体.得到的silicalite-2微米球直径大于10μm且具有高达460 m2·g-1的比表面积和0.74 cm3·g-1的孔体积.微米球的生成一定程度上解决了催化应用过程中催化剂的分离和回收问题.同时,水热晶化过程中由纳米粒子自组装而成的晶间介孔缩短了反应物分子的扩散路径,保持了分子筛纳米晶粒的优势.此外,钛活性位的引入并未明显影响MEL微米球的形貌和结构,含钛的MEL微米球TS(钛硅分子筛)-2在苯酚羟基化反应中具有与纳米尺寸TS-1(100-200 nm)相当的催化活性,且TS-2可以通过简单过滤得到,简化了纳米级TS-1的分离和回收过程.