活性炭负载纳米镍催化葡萄糖还原胺化反应

Catalytic reductive amination of glucose promoted by nano Ni supported on active carbon

在活性炭存在下硼氢化钠还原氯化镍制备了炭负载纳米镍(Ni/AC),用扫描电镜、透射电镜、X射线衍射分析表征了催化剂的结构,以一步法葡萄糖的还原胺化合成葡甲胺的反应为模型,考察了催化剂的制备、催化反应条件等因素对葡甲胺产率的影响。产物结构经核磁共振波谱表征。葡萄糖与甲胺先形成环状甲胺基葡萄糖,进而在催化剂作用下被还原成葡甲胺。研究发现,催化剂制备过程中的NaCl对催化反应具有抑制作用。三乙胺的加入能够提高催化剂的催化性能。在n葡萄糖∶nNi=9∶1,n葡萄糖∶n甲胺=1∶1.8,nNi∶n三乙胺=1∶2.5,80℃及氢气5.0 MPa下反应1 h,葡甲胺的产率达到了98%。

Supported nickel（Ni/AC）was prepared by reduction of NiCl2 with NaBH4 in the presence of activated carbon.The catalyst（Ni/C）was characterized by SEM,TEM,and XRD.The effects of preparation and catalytic reaction conditions on catalytic activity were evaluated by using reductive amination of glucose with methylamine as a model reaction.The reaction product was analyzed by NMR.The glucose reacted with methylamine to form cyclo-methylamino-glucose,then was reduced under the action of the catalyst to form N-methyl-D-glucamine.The NaCl formed in the reduction preparation of the catalyst inhibited the catalytic reductive amination.The catalyst performance could be improved by adding triethylamine.The yield of N-methyl-D-glucamine was up to 98% at reaction temperature of 80 ℃,H2 pressure of 5.0 MPa,molar ratio of glucose to Ni,glucose to MeNH2 and glucose to Et3N 9∶1;1∶1.8 and 1∶2.5,respectively.