In situ sulfonic acid-functionalized MIL-101(Cr) catalyzed liquid-phase Beckmann rearrangement of cyclohexanone oxime
In situ sulfonic acid-functionalized MIL-101(Cr) catalyzed liquid-phase Beckmann rearrangement of cyclohexanone oxime
复制标题
原位磺酸功能化MIL-101(Cr)催化环己酮肟的液相贝克曼重排
DOI：
10.1016/j.micromeso.2020.110031
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发表时间：
2020-05-01
影响因子：
5.2
通讯作者：
Wu, Jian
中科院分区：
文献类型：
--
作者：
Niu, Qiaoqiao;Liu, Mengjiao;Wu, Jian
我们采用不同的铬源和矿化剂原位制备了磺酸功能化的MIL-101（Cr）催化剂。我们通过X射线衍射，N-2-物理吸附，傅里叶变换红外，扫描电子显微镜，X射线光电子能谱，NH3程序升温脱附，电感耦合等离子体测量，这些催化剂的特点。随后，我们首次采用固体酸催化剂催化环己酮肟液相Beckmann重排合成己内酰胺。结果表明，以三氧化铬（CrO 3）为铬源，盐酸为矿化剂，在130 ℃下反应4 h，MIL-101（Cr）-S-1的转化率最高，为35.1%，选择性为65.9%。这优于使用九水合硝酸铬（III）[Cr（NO3）（3）中心点9 H（2）O]作为铬源和氢氟酸作为矿化剂制备的MIL-101（Cr）-S-2。这是因为MIL-101（Cr）-S-1具有比MIL-101（Cr）-S-2更高的酸含量和强度。MIL-101（Cr）-S-1可连续重复使用3次而不丧失催化活性。
We prepared in situ sulfonic-acid-functionalized MIL-101(Cr) catalysts using different chromium sources and mineralizers. We characterized these catalysts by X-ray diffraction, N-2-physical adsorption, Fourier-transform infrared, scanning electron microscopy, X-ray photoelectron spectroscopy, NH3 temperature-programmed desorption, and inductively coupled plasma measurements. We subsequently used the solid acid catalysts to catalyze the liquid-phase Beckmann rearrangement of cyclohexanone oxime to caprolactam for the first time. The results showed that when the reaction was carried out at 130 degrees C for 4 h with benzonitrile as the solvent, the MIL-101(Cr)-S-1, prepared using chromium trioxide (CrO3) as the chromium source and hydrochloric acid as the mineralizer, showed the highest conversion of 35.1% and selectivity of 65.9%. This was better than that of MIL-101(Cr)-S-2, which was prepared using chromium (III) nitrate nonahydrate [Cr(NO3)(3)center dot 9H(2)O] as the chromium source and hydrofluoric acid as the mineralizer. This occurred because the MIL-101(Cr)-S-1 had a higher acid content and strength than those of the MIL-101(Cr)-S-2. Additionally, the MIL-101(Cr)-S-1 could be reused three times in succession without loss of its catalytic activity.