杂多酸固载催化剂的合成及窄分子量纤维素制备的研究

Synthesis of HPW/MCM-41Solid Carrier Materials and Preparation of Narrow Weight Cellulose

通过水热合成法制备MCM-41型介孔分子筛,采用浸渍法负载磷钨酸于MCM-41介孔分子筛中,煅烧得到新型HPW/MCM-41固载催化剂。利用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、热重分析(TG)和扫描电镜(SEM)对固载催化剂进行表征;考察催化剂对棉纤维催化降解反应的性能。结果表明,新型HPW/MCM-41固载催化剂即持有了磷钨酸的Keggin结构,同时又保持了分子筛的完整介孔结构,具有催化、筛分双重性能。棉纤维催化降解反应数据显示,磷钨酸负载量、反应温度、催化剂用量、液固比及停留时间均影响HPW/MCM-41降解纤维素的性能。在单因素实验最佳反应条件下,棉纤维素降解产物的分子量分布较为均匀,降解产物的产率较优。

PW/MCM-41 catalyst was prepared by supporting phosphotungstic acid（HPW） on mesoporous MCM-41 molecular sieves via impregnation and then calcination. The said molecular sieves were synthesized by hydrothermal method. The catalysts were characterized by means of FTIR, XRD, TG and TEM. The original Keggin structure of HPW and mesoporous structure of MCM-41 molecular sieves were maintained after supporting HPW on MCM-41 molecular sieves. HPW/MCM-41 was used in degradation of cotton fiber. The test result indicates that the degradation reaction of cotton fiber with HPW/MCM-41 as degradant is influenced by the load amount of HPW, the reaction temperature, the dosage of catalyst, the ratio of liquid-solid and the retention time. Under the single factor reaction condition, the molecular weight distribution of degradation products for cotton fiber is well-distributed, and the productivity is superior.