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随着Si/Al比的增加,1-已烯逐渐与小笼羟基发生作用,至Si/Al为8.87时,可完全作用,这与吡啶吸附实验结果一致。低Si/Al比时,1-已烯可与部分剩余超笼羟基作用形成“氢键”,在约3300cm~(-1)产生吸收谱带;在高Si/Al比时,1-已烯亦可与硅终端羟基作用,使其伸缩振动谱带发生位移,在3700cm~(-1)处产生红外吸收。结炭过程中,1-已烯首先脱氢、环化形成低环芳烃,并进一步发生加成、环化反应;到结炭反应后期,环缩合、氢转移和支链化反应加强,使焦炭发生“老化”,具有了多支链、贫氢、多环芳烃的性质。随着Si/Al比的增加,结炭反应变缓,饱和结炭量减少,焦炭的“老化”程度降低。
With the increase of Si / Al ratio, 1-hexene gradually interacts with hydroxyl groups of small cages. When Si / Al is 8.87, it can be completely acted on, which is consistent with the experimental results of pyridine adsorption. At low Si / Al ratios, 1-hexene can form “hydrogen bonds” with some of the remaining super-cage hydroxyl groups and produce an absorption band at about 3300cm -1; at high Si / Al ratios, 1- It can also react with the silicon terminal hydroxyl to make the stretching vibration band shift and generate infrared absorption at 3700cm -1. In the process of carbon formation, 1-hexene first dehydrogenates and cyclizes to form low-cyclic aromatics and further undergoes addition and cyclization; to the late stage of the coking reaction, the ring condensation, the hydrogen transfer and the branching reaction are intensified, Occurred “aging”, with a multi-branched chain, hydrogen-depleted, polycyclic aromatic hydrocarbons nature. As the Si / Al ratio increases, the coking reaction slows down, the amount of saturated carbon decreases, and the “aging” of coke decreases.