摘要
通过乙二醇溶剂热法合成了尺寸均一的磁性Fe3O4纳米球,采用模板沉淀法对其进行介孔二氧化铈(mCeO2)层包裹,再将Ru纳米粒子负载在mCeO2表面制得Ru/Fe3O4@mCeO2磁性核壳结构催化剂。通过X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N2低温物理吸附和电感耦合等离子发射光谱(ICP-AES)等手段对催化剂进行表征,并将其应用于催化苯甲醇的绿色氧化。结果表明:通过添加模板剂的方法包覆介孔CeO2层,不仅使Ru较均匀地分散在载体表面,而且可以防止Ru在催化反应体系中的流失;利用H2还原法得到的金属Ru纳米颗粒,粒径为3~6 nm;Ru负载量为3.3%的催化剂,催化苯甲醇的分子氧氧化,353 K下反应7h后,苯甲醇的转化率为68.7%,苯甲醛选择性为84.7%;反应后催化剂可以通过外加磁场进行分离,循环5次以后,转化率和选择性都没有明显降低。
Ru/Fe3O4@mCeO2(mesoporous CeO2)magnetic core-shell structured catalyst was fabricated by templated precipitation of mCeO2 layer onto solvothermally prepared Fe3O4 nanospheres,followed by loading of Ru nanoparticles onto mCeO2.The catalyst was characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),low-temperature N2 adsorption and inductively coupled plasma atomic emission spectroscopy(ICP-AES)analyses,and utilized to catalyze the green oxidation of benzyl alcohol.The template-coated mCeO2 layer not only enables uniform dispersion of Ru on the support,but also prevents the loss of Ru in the catalytic reaction system.Ru nanoparticles with an average size of 3-6 nm were produced through the H2 reduction.For selective oxidation of benzyl alcohol by molecular oxygen at 353 K,the catalyst with 3.30%Ru loading resulted in 68.7%conversion of benzyl alcohol and 84.7%selectivity for benzal-dehyde.The catalyst can be magnetically separated and recycled without significant loss of catalytic efficiency even after 5 catalytic runs.
作者
孔丽萍
王呈呈
赵俊俊
张丽童
肖强
朱伟东
叶向荣
Liping Kong;Chengcheng Wang;Junjun Zhao;Litong Zhang;Qiang Xiao;Weidong Zhu;Xiangrong Ye(Key Laboratory of the Ministry of Education for Advanced Catalysis Materials,Institute of Physical Chemistry,Zhejiang Normal University,Jinhua Zhejiang)
出处
《物理化学进展》
2016年第2期27-38,共12页
Journal of Advances in Physical Chemistry
基金
国家自然科学基金支持项目,KYZKJY14133。
关键词
磁性催化剂
核壳结构
二氧化铈
Ru
苯甲醇氧化
Magnetic Catalyst
Core-Shell Structure
Cerium Oxide
Ru
Benzyl Alcohol Oxidation
