摘要
测定了不同条件下脱铝的Y型沸石和一些催化剂的N_2吸附等温线,并将这些等温线转换成V_(a～t)(吸附量～层厚)图.由图计算了各样品的表面积和孔体积,其中用V_(a～t)图高相对压力的直线斜率计算样品的外表面积(定义为大于10.0nm孔的BET表面积)还不曾见报道.对脱铝Y型沸石,从这条直线还可计算出改性过程中产生的二次孔的表面积和孔体积.文中选出有代表性的6种V_(a～t)图,并由此对6个样品的孔结构进行了分析.同时,用经典的毛细管冷凝法计算了一些样品的孔分布曲线,发现各样品的最可几孔半径都出现在2.0nm左右.
Isotherms of N_2 absorption at 77. 4 K have been determined experi mentally for the dealuminated Y zeolites prepared under different conditions and for some catalysts. These isotherms are transformed into V_a～t plots and from them the specific surface areas and pore volumes for all samples are calculated. The external surface areas of the samples can been evaluated from the slopes of the straight lines in the range of high relative pressure. The surface areas and volumes of the secondary pore sestems for the dealumi nated Y zeolites can also been calculated from these straight lines. In this paper, typical V_a～t plots of six samples are chosen to analyse the proper ties of pore structures. The pore size distribution of the samples calculated from N_2 desorption ranges of the isotherms according to the equivalent cy lindrical model show that the most probable pore radii are all centered near 2.1nm.
出处
《石油炼制》
CSCD
1991年第12期52-55,共4页
