稀土离子改性膨润土对联苯的选择性硝化

Selective Nitration of Biphenyl by Rare-Earth Ions Modified Bentionite

研究了以不同稀土离子改性的膨润土为催化剂,选择性催化联苯的硝化反应.采用傅里叶红外吸收光谱和X射线衍射对稀土离子改性的膨润土进行表征.硝化研究结果表明改性的膨润土对联苯的硝化在硝酸/二氯甲烷体系中的对位选择性高.在该体系中,当硝酸与联苯的摩尔比为3∶1,适量硝酸铈改性的膨润土作为催化剂,15℃下反应10 h后,所得联苯的一硝化产物的最佳邻对比为0.71,硝化产率可达90.8%.该催化剂经过简单处理,煅烧再生后可重复利用,其催化效果基本不变,该工艺环境亲和性好.

The selective nitration of biphenyl catalyzed by rare-earth ions modified bentionite was investigated.The rare-earth ions modified bentionite was characterized by Fourier transform infrared spectroscopy and X-raydiffraction.The results of nitration experiment show that the para selectivity of biphenyl nitration in nitric acid/dichloromethane system is good.The ratio of ortho-para of biphenyl mononitration product is 0.71 and the yieldof nitration is up to 90.8% in nitric acid/ dichloromethane system catalyzed by appropriate dosage of ceriumnitrate modified bentionite at the molar ratio of nitric acid to biphenyl of 3∶1,and 15 ℃ for 10 h.The catalystscan be reused by simple treatment and regeneration,with good effect and environmental friendliness.