Cr2O3/SiO2催化苯酚与碳酸二乙酯邻位烷基化反应

化工进展

Cr2O3/SiO2催化苯酚与碳酸二乙酯邻位烷基化反应

贾泉，薛冰，许杰，李永昕

常州大学石油化工学院，江苏常州 213164

出版日期:2011-05-05 发布日期:2011-05-05

Ortho-selective alkylation of phenol with diethyl carbonate over Cr2O3/SiO2 catalyst

JIA Quan，XUE Bing，XU Jie，LI Yongxin

School of Petrochemical Technology，Changzhou University，Changzhou 213164，Jiangsu，China

Online:2011-05-05 Published:2011-05-05

摘要/Abstract

摘要：

以Cr(NO₃)₃?9H₂O为前体，采用等体积浸渍法制备了一系列不同Cr₂O₃负载量的Cr₂O₃/SiO₂催化剂；在固定床连续微反装置上，考察了Cr₂O₃/SiO₂催化剂对苯酚与碳酸二乙酯邻位烷基化反应的催化性能；采用XRD、NH₃-TPD、CO₂-TPD和吡啶吸附、红外等手段对催化剂进行了表征。实验结果表明，随着Cr₂O₃负载量的增加，苯酚的转化率和邻乙基苯酚的选择性均逐渐增加；当Cr₂O₃负载量达到7.5%时，苯酚的转化率和邻乙基苯酚的选择性均达到最大值，分别为48%和67%。催化剂的表征结果表明，L酸中心是苯酚邻位烷基化反应的活性中心，苯酚转化率和邻乙基苯酚选择性的变化主要是由催化剂的酸、碱中心数目变化引起的。

Abstract:

Cr₂O₃/SiO₂ catalysts with different Cr₂O₃loadings were prepared by impregnation with Cr(NO₃)₃?9H₂O as precursor．Ortho-selective alkylation of phenol with diethyl carbonate was performed in a continuous flow fixed-bed reactor filled with Cr₂O₃/SiO₂ catalysts．The Cr₂O₃/SiO₂ catalysts were characterized by means of XRD，NH₃-TPD，CO₂-TPD and FT-IR with pyridine adsorption．The results indicated that with increasing Cr₂O₃loading，conversion of phenol and selectivity to o-ethylphenol increased；when Cr₂O₃loading reached 7.5%，conversion of phenol and selectivity for o-ethylphenol reached a maximum of 48% and 67%，respectively．The catalyst characterization results showed that the Lewis acid sites were the active centers of ortho-selective alkylation of phenol；and the variations in phenol conversion and selectivity to o-ethylphenol could be mainly ascribed to the change in the number of acid sites and base sites．

贾泉，薛冰，许杰，李永昕. Cr2O3/SiO2催化苯酚与碳酸二乙酯邻位烷基化反应 [J]. 化工进展.

JIA Quan，XUE Bing，XU Jie，LI Yongxin. Ortho-selective alkylation of phenol with diethyl carbonate over Cr2O3/SiO2 catalyst[J]. Chemical Industry and Engineering Progree.