邻甲酚液相原位加氢反应

Research on in situ Hydrogenation of o-Cresol over Ni/CMK-3 Catalysts

以Ni/CMK-3为催化剂,采用BET比表面积、X射线衍射和氢气程序升温还原对催化剂进行了表征.考察了不同Ni负载量、反应温度、反应初始压力及反应时间条件下,甲醇水相重整制氢与邻甲酚原位加氢的耦合反应.结果表明,当Ni负载量为20%、反应温度为230℃、反应前冷压为0.1 MPa、水-甲醇-模型化合物摩尔比为50∶15∶1及反应9 h时,邻甲酚转化率最高为45.4%.分别对比了甲醇、甲酸、甘油和异丙醇作为供氢溶剂对原位加氢反应的影响,其中以甲酸为供氢溶剂时,邻甲酚的转化率最高达82.2%.对比了甲酚3种同分异构体原位加氢的效果,发现邻甲酚和间甲酚的反应效果相差不大,而对甲酚的转化率则远低于邻甲酚和间甲酚.对20%Ni/CMK-3在原位加氢实验中的使用寿命进行了考察.

In situ hydrogenation was studied by means of Ni loading, temperature, initial pressure, and reac-tion time over Ni/CMK-3 catalysts. The catalysts were characterized by X-ray diffraction（ XRD） , H2 tempera-ture programmed reduction（ H2-TPR） and N2 adsorption-desorption isotherms. The results revealed that the optimal conditions were confirmed as follow： Ni loading of 20%（ mass fraction ） , reaction temperature of 230 ℃, initial pressure of 0. 1 MPa, reaction time of 9 h for in situ hydrogenation. The maximum conversion of o-cresol in optimal condition was determined as 47. 56%. Compared with the effect of hydrogen donor solvents, formic acid was the best of four kinds of solvents. The comparsion of cresol isomers, recyclability of Ni/CMK-3 were also discussed.