温和条件下磁性Pd-MgFe2O4/MgAl(O)催化4-氯苯酚高效加氢脱氯

以镁铁尖晶石MgFe₂O₄为磁核，在磁核表层包覆MgAl水滑石后经高温焙烧形成MgAl （O）复合氧化物包覆的磁性载体MgFe₂O₄/MgAl （O），进而负载纳米金属Pd制成磁性催化剂Pd-MgFe₂O₄/MgAl （O）.通过X射线衍射（XRD）、X射线光电子能谱分析（XPS）、傅里叶红外光谱（FT-IR）、透射电镜（TEM）、扫描电子显微镜（SEM）、选区电子衍射（SAED）、比表面积（S_BET）和振动样品磁强计（VSM）等手段对催化材料进行表征.结果表明，MgFe₂O₄-LDH转化为磁性MgFe₂O₄/MgAl （O）载体有利于催化材料比表面积的增加、结构稳定性的提升及相应催化活性位点的增加，进而有利于提升4-氯苯酚高效加氢脱氯效率.研究进一步考察了催化剂负载量、催化剂用量、底物浓度、反应温度、反应溶剂等条件对4-氯苯酚降解效率的影响.结果发现，在优化反应条件下催化反应的转换频率TOF （0.04 s^-1）可媲美常温、常压、无碱性添加剂等温和条件下4-氯苯酚高效加氢脱氯反应的最佳文献报道水平.磁性催化剂Pd-MgFe₂O₄/MgAl （O）循环使用4次后仍保持很好的催化活性.

Magnetic Pd-MgFe2O4/MgAl(O) catalyzed highly efficient hydrodechlorination of 4-chlorophenol under mild conditions

The MgFe₂O₄ was used as the magnetic core,which was coated with MgAl hydrotalcite.After high-temperature calcination, MgAl(O) compound oxide based magnetic carrier MgFe₂O₄/MgAl(O) was formed.Magnetic catalyst Pd-MgFe₂O₄/MgAl(O) was prepared by nano-metal Pd loading.The material were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy (XPS),fourier infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),selected area electron diffraction(SAED),brunauer emmett teller method(S_BET) and vibrating sample magnetometer(VSM) measurement.The study showed that the specific surface area,the structural stability and the corresponding catalytic active site of the catalytic material was enhanced by the transformation of MgFe₂O₄-LDH into the magnetic MgFe₂O₄/MgAl(O) carrier,which was beneficial to improve the efficiency of the hydrodechlorination of 4-chlorophenol.The removal efficiency of 4-chlorophenol was investigated under different conditions of catalyst loading,catalyst concentration,substrate concentration,reaction temperature as well as solvent.In comparison with literature,the TOF (0.04 s^-1) of the catalytic 4-chlorophenol hydrodechlorination reaction under optimal reaction conditions approach one of the best efficiency under mild conditions such as room temperature,ambient pressure and no base additive.The catalytic efficiency of the magnetic catalyst Pd-MgFe₂O₄/MgAl(O) was well maintained after 4 recycle times.