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化学学报
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化学学报 ›› 1990, Vol. 48 ›› Issue (1): 42-47. 上一篇    下一篇

研究论文

原位红外光谱法研究脱铝Y型沸石表面羟基及异丙苯裂解反应

鲍书林;于秋明;须沁华   

  1. 南京大学化学系
  • 发布日期:1990-01-15

In-situ IR spectra studies of the surface hydroxyl groups and cumene cracking on dealuminated Y zeolites

BAO SHULIN;YU QIUMING;XU QINHUA   

  • Published:1990-01-15

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本文用原位红外光谱法, 以自行设计的红外池, 采用流动体系研究了NH4Y及用EDTA配位脱铝的Y型沸石上的表面羟基, 苯及异丙苯在不同温度下的吸附, 以及用脉冲进样原位红外研究了异丙苯裂解反应。发现在脱铝Y型沸石(DAIY)中除Y型沸石有的3620和3535cm^-^1表面羟基峰外, 在3724cm^-^1处又出现一个与脱铝“空穴"Si-OH有关的吸收峰, 且此峰随脱铝量增加而增加, 脱氨过程的研究表明超笼中羟基具有酸性, 苯及异丙苯Y型或DNIY型沸石上均与超笼中羟基作用。在360℃时异丙苯裂解反应的活性中心主要是超笼中羟基, 催化剂失活主要是由于炭沉积在活性位上所致。

关键词: 红外分光光度法, 苯, 沸石, 吸附, 表面化学, 羟基, 催化剂中毒, 裂解反应, 原位, 异丙苯 P

There are two OH frequencies at 3620 and 3535 cm-1 on Y zeolite, corresponding to the OH groups situated in supercage and sodalite cage, resp. While on DAlY a new band at 3724 cm-1 appeared which was assigned to Si-OH located in the empty hole resulted from the dealumination. After the adsorption of benzene and cumene on the Y and DA1Y zeolites, the 3620 cm-1 band disappeared, which implies that the adsorption occurred in the supercages. The acidic OH groups absorbed at 3620 cm-1 are the main active sites of the cumene cracking.

Key words: INFRARED SPECTROPHOTOMETRY, BENZENE, ZEOLITE, ADSORPTION, SURFACE CHEMISTRY, HYDROXY GROUP, CATALYST POISONING, CRACKING REACTION, IN-SITU, ISOPROPYL BENZENE P

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