【摘要】 采用有机-无机复合酸(柠檬酸和磷酸)改性超稳Y(USY)分子筛,分别考察了柠檬酸和磷酸单独改性和两种酸相复合进行改性的改性效果,以及复合改性两种酸加料方式的影响,并通过N2吸脱附、XRD、FT-IR和NH3-TPD等分析手段,对改性分子筛的结构及性能进行了表征,进而对改性的机理进行了初步的探讨。对于有机酸和无机酸复合改性,最适宜的加料顺序为先加柠檬酸后加磷酸。复合改性的样品具有较大的比表面积和较高的二次孔孔容,在保持较高结晶度的同时具有较高的骨架硅/铝比,酸量明显下降,中强酸比例明显增加;改性体系改性条件缓和,具有良好的工业化前景。更多还原

【Abstract】 Citric acid(organic acid) combined with phosphoric acid(inorganic acid) were used to modify the commercial USY samples for investigation of the effects of acid modification.The structure and properties of the modified samples were characterized by low temperature nitrogen adsorption method,XRD,FT-IR,and NH3-TPD.Results show that the optimum procedure for acid treatment was first the citric acid and then the phosphoric acid.The modified USY samples were of large surface area,rich secondary pore volume,high Si/Al ratio as well as superior crystallinity.Additionally,the total amount of acidity decreased while the proportion of medium strong acid increased.The reaction conditions of modification were relatively mild.The results show an inspiration for the better preparation and utilization of this kind of zeolites.更多还原