钛酸盐纳米纤维形貌控制及固体碱催化性能

Morphology Control in Synthesis of the Titanate Nanofiber and Its Application as a Solid Base Catalyst

摘要:

研究了钛前驱体、碱种类和合成温度对水热法制备钛酸盐纳米纤维形貌的影响。结果显示，以无定型钛凝胶为前驱体和KOH为碱，均有利于形成无孔的钛酸盐纳米纤维，在90℃下得到了形貌均一，长径比为1000，比表面积为311 m2/g的钛酸盐纳米纤维。以钛酸盐纳米纤维为载体，采用浸渍法负载了碱金属卤化物作为固体碱催化剂。该催化剂在环氧丙烷醇化制备丙二醇单甲醚的反应中，降低了反应温度和时间，表现出良好的碱催化活性。CO2-TPD结果显示，掺杂后的催化剂的碱含量是空白载体的2倍，并出现中强碱活性中心。

Abstract:

The influences of titanium precursor, base type and temperature on morphology of the titanate nanofiber（TiNF） synthesized by hydrothermal method were studied. It is found that the precursor of amorphous titania gel and base of KOH are both leading to the generation of nonporous TNFs and an evenly distributed and elongated TNFs were synthesized at 90℃ with the length to diameter ratio of 1000 and specific area of 311m2/g. Taking thus made TiNFs as the support, a solid base catalyst was prepared by impregnation of the alkaline halide which has demonstrated excellent basic activity in synthesis of propylene glycol monomethyl ether at lower temperature and shorter time by methanol addition reaction of epoxy propane. Temperature programmed desorption of CO2 test has found the amount of the basic sites on catalyst surface doubled after impregnation of alkaline halide on the blank TiNF support and also appeared the new basic sites of medium and strong strength.