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用多晶X 射线衍射法测定了高温水蒸汽处理后ZSM-5的晶体结构。处理后样品的空间群下降为C_(2h)~5-P_2_(1/n),晶胞参数为a=20.117(3)(?),b=19.877(3)(?),c=13.447(3)(?),α=90.17(5)°。它仍保持ZSM-5的两个垂直相交的通道系统,但其“Z”字形通道开口缩小,通道折角由处理前的156°降至147°,直通道开口由椭圆形变成圆形。两个通道开口直径皆为5.2(?),都近似正十元环。通道的几何构型如此改变,并使两个通道交叉处的空间以及通道的总体积减小,因此处理后提高了临氢降凝反应的选择性。
The crystal structure of ZSM-5 after high temperature steam treatment was determined by polycrystalline X-ray diffraction. The space group of the treated samples decreased to C 2h -5 P 2 1 / n, the unit cell parameters were a = 20.117 (3) (?), B = 19.877 (3) and c = 13.447 3) (?), Α = 90.17 (5) °. It still maintains the two vertically intersecting channel systems of the ZSM-5, but its “Z” shaped channel opening narrows and the channel angle decreases from 156 ° before processing to 147 °. The straight channel opening changes from oval to round. Both channels have an opening diameter of 5.2 (?), Both of which are approximately ten-ring rings. The geometric configuration of the channels changes in such a way that the space at the intersection of the two channels and the total volume of the channels are reduced, thus increasing the selectivity of the hydrodedenylation reaction after treatment.