化学学报 ›› 2017, Vol. 75 ›› Issue (7): 686-691.DOI: 10.6023/A17030134 上一篇    下一篇

研究论文

温和条件下钌/氮掺杂碳纳米笼的苯乙酮选择性催化加氢性能

蔡跃进, 刘晨霞, 卓欧, 吴强, 杨立军, 陈强, 王喜章, 胡征   

  1. 南京大学化学化工学院 介观化学教育部重点实验室 南京 210023
  • 收稿日期:2017-03-31 出版日期:2017-07-15 发布日期:2017-07-18
  • 通讯作者: 吴强, 王喜章 E-mail:wqchem@nju.edu.cn;wangxzh@nju.edu.cn
  • 基金资助:

    受国家重大科学研究计划(纳米专项,No.2013CB932902),国家自然科学基金(Nos.21473089,51232003,21373108,51571110,21573107),常州市科技计划(No.CE20130032)和江苏高校优势学科建设工程项目资助.

Ruthenium Nanoparticles Supported on Hierarchical Nitrogen-Doped Carbon Nanocages for Selective Hydrogenation of Acetophenone in Mild Conditions

Cai Yuejin, Liu Chenxia, Zhuo Ou, Wu Qiang, Yang Lijun, Chen Qiang, Wang Xizhang, Hu Zheng   

  1. Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023
  • Received:2017-03-31 Online:2017-07-15 Published:2017-07-18
  • Contact: 10.6023/A17030134 E-mail:wqchem@nju.edu.cn;wangxzh@nju.edu.cn
  • Supported by:

    Project supported by the National Basic Research Program of China (973 Program,No.2013CB932902),the National Natural Science Foundation of China (Nos.21473089,51232003,21373108,51571110,21573107),Changzhou Technology Support Program (No.CE20130032),and the Priority Academic Program Development of Jiangsu Higher Education Institutions.

共轭羰基化合物的羰基选择性加氢反应被广泛用于制备重要的药物和化学中间体.利用氮掺杂碳纳米笼(hNCNC)大的比表面积和掺杂氮原子的锚定作用,构建了10 wt% Ru负载量的Ru/hNCNC催化剂,尺寸约2.4 nm的Ru纳米颗粒高度均匀地分散在hNCNC表面.用于催化苯乙酮选择性加氢制1-苯乙醇,在50.0℃、2.0 MPa H2的温和条件下,展现出优异的催化加氢性能:反应2.0 h后的苯乙酮转化率和1-苯乙醇选择性分别达到96.2%和95.8%,远优于未掺杂碳纳米笼(hCNC)和活性炭负载的Ru催化剂;循环使用6次后,其苯乙酮转化率仅略有下降(从96.2%到94.0%),明显优于Ru/hCNC.Ru/hNCNC的优异催化性能可归因于:hNCNC大的比表面积和掺杂氮原子的锚定作用有利于Ru纳米粒子的分散和固载、独特的微孔-介孔-大孔共存的分级孔结构有利于传质、掺杂氮原子有效调变了Ru催化剂的电子结构.

关键词: 苯乙酮, 选择性加氢, 1-苯乙醇, 氮掺杂碳纳米笼,

The selective hydrogenation of carbonyl groups of the conjugated carbonyl compounds is an important reaction in the pharmaceutical and chemical industries,and several selective hydrogenation approaches have been developed.Using stoichiometric hydrides (LiAlH4,NaBH4,etc.) as hydrogenation reagents has some shortcomings,including the unsatisfied selectivity of target product owing to the simultaneous hydrogenation of conjugated double bonds and carbonyl groups,as well as the flammability and explosibility of hydrides.Hydrogen is an alternative hydrogenation reagent,which can selectively hydrogenate carbonyl groups by homogeneous and heterogeneous catalytic processes.The noble metal (Ru,Pd,etc.) complexes were usually used in the homogeneous catalytic process,which caused some serious issues such as the metal residues in products and the difficulties of recovering precious catalysts.These problems can be effectively solved by the heterogeneous catalytic process using the supported catalysts.Carbon-based materials,metal oxides and β-Zeolite are commonly used supports.Among them,carbon-based materials are preferable due to their features of abundant morphologies and structures,good stability,adjustable specific surface areas and pore structures,easy doping,etc.Interestingly,the introduction of heteroatoms into carbon matrix can provide a plenty of anchoring sites to disperse catalytically active species and regulate the interaction between active species and support,and hence promotes their catalytic properties.In addition,the high specific surface areas of the supports are beneficial to the dispersion of the catalytically active species.In recent years,our group has developed hierarchical carbon-based nanocages by in situ MgO template method.The mesostructured nanocages feature the high specific surface area,coexisting micro-meso-macropore structure,rich defects,easy doping,etc.,which demonstrated excellent electrochemical performance in energy conversion and storage.Herein,taking advantage of the anchoring functions of nitrogen heteroatoms and high specific surface area of nitrogen-doped carbon nanocage (hNCNC),10 wt% Ru/hNCNC catalyst was conveniently prepared by microwave-assisted ethylene glycol reduction.The Ru nanoparticles of ca.2.4 nm are highly dispersed on the outer surface of hNCNC.As the catalyst for the selective hydrogenation of acetophenone to 1-phenylethanol,Ru/hNCNC exhibits excellent catalytic activity,selectivity and recyclability in mild conditions of 50.0℃ and 2.0 MPa H2.Specifically,after 2.0 h of reaction,the conversion of acetophenone is up to 96.2%,obviously higher than that of Ru/carbon nanocages (Ru/hCNC,80%) and Ru/AC (0.7%),and the selectivity of 1-phenylethanol is 95.8%.More importantly,after recycle use for 6 times,the conversion of acetophenone only slightly drops from 96.2% to 94.0% for Ru/hNCNC,while obviously decreases from 80.0% to 63.0% for Ru/hCNC.Such excellent catalytic performance of Ru/hNCNC could be ascribed to the synergism of (i) the high dispersion of Ru nanoparticles owing to the high specific surface area and nitrogen doping of hNCNC,(ii) the regulated electron structure of Ru catalyst owing to nitrogen incorporation,iii) the facilitated mass transportation by unique hierarchical pore structures of hNCNC support.

Key words: acetophenone, selective hydrogenation, 1-phenylethanol, nitrogen-doped carbon nanocages, ruthenium