介孔碳负载纳米Pt高效催化卤代芳香硝基化合物选择性还原制卤代芳胺

Highly Selective Reduction of Halogenated Nitroarenes to Haloanilines on Mesoporous Carbon-Supported Pt Nanoparticles

卤代芳胺主要通过卤代芳硝基化合物选择性还原制备,但加氢过程中常伴随着不同程度的脱卤反应而降低反应的选择性。本文采用柠檬酸镁快速热解法制备的介孔碳材料(MC-c)做为载体,制备了MC-c负载的高分散Pt纳米粒子(Pt/MC-c),并将其用于多种卤代芳香硝基化合物选择性还原制卤代芳胺。研究结果表明,Pt/MC-c催化剂在选择性还原反应中表现出了较高的反应活性和100%的卤代芳胺选择性。邻氯硝基苯为模型反应物的循环实验表面,Pt含量为2%的2%Pt/MC-c催化剂在循环12次后,反应活性和选择性没有明显变化,仍然保持在78%和100%。表明制备的Pt/MC-c催化剂在卤代芳香硝基化合物选择性还原反应中具有优异的反应稳定性。优异的催化性能主要归因于Pt颗粒与介孔碳载体之间的协同作用。

Halogenated aromatic amines are mainly produced by hydrogenation of halogenated nitroarenes over metal catalysts,however,dehalogenation reactions were always inevitably occurred during the hydrogenation process.Herein,we demonstrated that highly dispersed platinum nanoparticles supported on mesoporous carbon materials(Pt/MC-c)can be facilely prepared,and the synthesized Pt/MC-c catalyst exhibited high catalytic activity and almost 100%chemoselectivity of haloanilines for selective hydrogenation of various halogenated aromatic nitro compounds.In a typical cyclic experiment using o-chloronitrobenzene as a model reactant,the 2%Pt/MC-c catalyst still showed considerable catalytic performance(conversion 78%and selectivity 100%)after 12 cycles.The excellent catalytic property was mainly due to the synergistic effect between Pt particles and carbon.