高效苯酚选择性加氢催化剂的制备和性能研究

发布时间：2018-04-27 09:57

  本文选题：生物油 + 苯酚　； 参考：《西安石油大学》2017年硕士论文

【摘要】：以NiCl2、Cu(NO3)2、Ce(NO3)3为原料,KBH4为还原剂,采用浸渍法和化学还原法制备了负载型和非负载型Ni-Cu-Ce-B催化剂。以生物油中主要的含氧模型化合物苯酚加氢制备环己酮为反应体系,利用固定床反应器催化剂评价装置,设计了三水平三因素正交实验,考察了铜镍比、铈镍比、负载量对催化剂活性和选择性的影响,确定出最佳的催化剂制备条件。通过设计三水平五因素正交实验,考察了反应温度、反应压力、液时空速、氢气/苯酚体积比对反应活性和选择性的影响,确定出最佳的反应条件。最后,分别考察了催化剂重复使用次数、储存时间、助剂、载体对催化剂活性和选择性的影响,并研究了助剂Cu、Ce在Ni-B/γ-Al2O3催化剂表面的作用机理。实验结果表明,最佳的催化剂制备条件为:铜镍物质的量比0.3,铈镍物质的量比0.2,负载量30%。最佳的反应条件为:反应温度150℃、反应压力1.0 MPa、反应时间1.5 h、液时空速2.0 h-1、氢气/苯酚体积比50/1。在最佳的催化剂制备和反应条件下,催化剂的活性为47.39%,催化剂选择性可达29.37%。所制备的Ni-Cu-Ce-B为非晶态纳米级催化剂,活性组分分散良好。加入助剂Cu和Ce后,Ni-B/γ-Al2O3催化剂的热稳定性加强,比表面积增大,活性和选择性有所提高。催化剂储存一段时间后仍保持了较好的活性和选择性。Cu向Ni的电子转移效应和Ce对于催化剂碱性的提高都有利于增大催化剂的选择性。
[Abstract]:Supported and unsupported Ni-Cu-Ce-B catalysts were prepared by impregnation method and chemical reduction method using NiCl2Cu CuNO 3H 3 as raw material KBH4 as reducing agent. Cyclohexanone was prepared by hydrogenation of phenol, one of the main oxygen-containing model compounds in bio-oil, as a reaction system. The three-level and three-factor orthogonal experiment was designed by using a fixed-bed reactor catalyst evaluation apparatus. The copper-nickel ratio and cerium / nickel ratio were investigated. The effect of loading amount on the activity and selectivity of the catalyst was studied, and the optimum preparation conditions were determined. The effects of reaction temperature, reaction pressure, liquid space-time velocity and the volume ratio of hydrogen to phenol on the activity and selectivity of the reaction were investigated by designing a three-level and five-factor orthogonal experiment, and the optimum reaction conditions were determined. Finally, the effects of reusing times, storage time, auxiliaries and supports on the activity and selectivity of Ni-B/ 纬 -Al 2O 3 catalyst were investigated, and the mechanism of the effect of CuCe on the surface of Ni-B/ 纬 -Al 2O 3 catalyst was studied. The experimental results show that the optimum preparation conditions are as follows: the ratio of copper to nickel is 0.3, the ratio of cerium to nickel is 0.2, and the loading amount is 30. The optimum reaction conditions are as follows: reaction temperature 150 鈩，

本文编号：1810265