活性炭负载Pt-Fe双金属催化剂催化对氯硝基苯选择性加氢  

Selective Hydrogenation of p-Chloronitrobenzene Catalyzed by Activated Carbon Supported Fe-Pt Bimetallic Catalyst

作　　者：谷牧[1] 何代平[1,2] 江平[1] 尹兴春 陈虎[1] 

机构地区：[1]重庆师范大学化学学院,重庆400047 [2]重庆师范大学物理与电子工程学院光电功能材料重庆市重点实验室,重庆400047

出　　处：《应用化学》2015年第10期1164-1169,共6页Chinese Journal of Applied Chemistry

基　　金：重庆市基础与前沿研究计划(cstc2013jcyjA50006);重庆市教委科学技术研究项目(KJ110621);重庆师范大学重点基金(12XLZ12;10XLR021)资助~~

摘　　要：采用浸渍还原法制备了活性炭负载Pt-Fe双金属催化剂(Pt-Fe/AC),考察了其催化对氯硝基苯加氢性能。与Pt/AC催化剂比较,该催化剂对催化对氯硝基苯加氢表现出高活性和优异的抑制脱氯性能,在乙醇为溶剂、催化剂Pt0.003-Fe0.04/AC(下标为元素在催化剂中的质量分数)用量为0.02 g/g对氯硝基苯、1 MPa H2和30℃条件下反应150 min,对氯硝基苯完全转化为对氯苯胺,而且即使在较高的反应温度和H2压力下,脱氯反应也得到了完全抑制。采用X射线衍射(XRD)、透射电子显微镜(TEM)及X射线光电子能谱(XPS)等技术手段对Pt-Fe/AC催化剂进行了表征。结果表明,Pt、Fe高度分散在活性炭上,Pt与Fe之间的相互作用对纳米Pt粒子的电子结构有一定的调变作用,使纳米Pt处于缺电子态,减弱了Pt与对氯苯胺苯环之间的电子反馈,这可能是Pt-Fe/AC对催化对氯硝基苯加氢表现出高活性和优异的抑制脱氯性能的主要因素。An activated carbon supported Pt-Fe bimetallic catalyst（Pt-Fe/AC） was prepared by impregnation reduction method, and its catalytic performance for selective hydrogenation of p-chloronitrobenzene（p-CNB） to p-chloroaniline（p-CAN） was investigated. Compared with Pt/AC catalyst, the Pt-Fe/AC catalyst exhibited higher activity and excellent inhibition of dechlorination. One hundred percent selectivity towards p-CAN at complete conversion ofp-CNB was achieved under the following conditions： 30 % for 150 min, 1.0 MPa H2, ethanol as solvent, and 0. 02g Pt0.0o3-Fe0.o4/AC catalyst（ the lower case numbers represent the mass fraction of related metal in the catalyst） per gram p-CNB. The high selectivity towards p-CAN remained even at high temperature and H, pressure. The as-prepared catalysts were characterized using X-ray diffraction （XRD）, transmission electron microscopy（TEM）, and X-ray photoelectron spectroscopy（XPS）. The results show that Pt and Fe are well dispersed on the AC surface. The higher activity and excellent selectivity of the Pt0.oo3- Feo04/AC are primarily derived from the electron-deficient state of Pt due to the electronic effect of Pt nanoparticles with Fe, which weakened the extent of electron feedback from Pt particles to the aromatic ring of p-CAN and suppressed the hydrodechlorination of p-CAN.

关 键 词：选择性加氢 活性炭 铂铁双金属 氯代硝基苯 氯代苯胺 

分 类 号：O643[理学—物理化学]