| The inorganic substance such as zeolite MCM-41,and MgO was selected assynthetic nanopalladium catalysts to improve the problems of homogeneous catalystfor the Suzuki coupling reaction, which is difficult to recovery, hard to reuse and easyto leave over in the products, and the ligand is difficult to be synthesized. Thecatalysts were characterized by thermogravimetry （TG）, X-ray diffraction （XRD）,X-ray photoelectron spectroscopy （XPS） and inductively coupled plasma-atomicemission spectrometry （ICP-AES）. The Suzuki coupling reactions betweenbrominated aromatics and boronic acid have been investigated the influences ofsolvent, proportion of solvent and water, base, time, and temperature on catalyticactivity. The optimal conditions of the catalyzed Suzuki reaction have been filteredout.Zeolite MCM-41supported nanopalladium catalysts were synthesdized viareduction impregnation method. The palladium content of catalyst is0.013mmol/g.When ethanol/H2O and K2CO3were used as the solvent and base, the yield of94.76%for the Suzuki coupling reaction was gotten by using0.26×10-3mmol Pdwithin1h at60℃. The reaction yield for the third recycle of catalyst reach84.52%and60.57%for the fourth recycle.Al2O3supported nanopalladium catalysts were synthesdized via reductionimpregnation method. The palladium content of catalyst is0.041mmol/g though theICP—AES. When ethanol/H2O and K2CO3were used as the solvent and base, theyield of97.71%for the Suzuki coupling reaction was gotten by using0.82×10-3mmol Pd within1h at60℃. The reaction yield for the forth recycle of catalyst reach85.31%.MgO supported nanopalladium catalysts were synthesdized. The palladiumcontent of catalyst is0.364mmol/g though the ICP-AES. When methanol/H2O andKOH were used as the solvent and base, the yield99.61%for the Suzuki couplingreaction was gotten by using3.64×10-3mmol Pd within1h at50℃. for the Suzukicoupling reaction. The reaction yield for the forth recycle of catalyst reach86.65%.. |
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