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采用化学沉淀法将磁性基质与二维层状水滑石组装制备了磁性的水滑石,再利用浸渍法和滴加吸附的负载方法制备了磁性水滑石负载纳米钯催化剂。通过XRD、ICP-AES、TG、氢气脉冲吸附等分析手段对磁性催化剂晶型结构、形貌及金属分散度进行了表征,考察了用磁性水滑石负载纳米钯催化剂对不同碱、溶剂、溶剂与水比例、时间、温度、催化剂用量等条件对Suzuki反应的影响。实验结果表明,水滑石赋予磁性后结构并没有改变,仍然具有较高的催化活性。反应的最佳条件为:碳酸钾作碱、溶剂为乙醇、与水比例为1∶5、反应温度为60℃、反应1h、催化剂用量分别为3.6×10-3mmol和4.8×10-3mmol,催化剂重复三次产物收率仍可保持在90%以上。
The magnetic hydrotalcite was prepared by the chemical precipitation method, and the magnetic hydrotalcite-supported nano-palladium catalyst was prepared by impregnation method and dropping adsorption method. The crystal structure, morphology and metal dispersion of the magnetic catalyst were characterized by means of XRD, ICP-AES, TG and hydrogen pulse adsorption. The effects of different hydrotalcite loaded nano-palladium catalysts on the structure, morphology, Water ratio, time, temperature, catalyst dosage and other conditions on the Suzuki reaction. The experimental results show that hydrotalcite does not change the structure of the magnet after giving it, and still has high catalytic activity. The optimal reaction conditions were as follows: potassium carbonate as base, solvent as ethanol, the ratio of water to water was 1: 5, reaction temperature was 60 ℃, reaction time was 1h, catalyst dosage was 3.6 × 10-3mmol and 4.8 × 10-3mmol, Repeated three times the product yield can still be maintained at 90%.