钕对苯直接氧化制苯酚催化反应的促进作用

采用溶胶凝胶法制备Cr/Al2O3,Nd-Cr/Al2O3催化剂,通过X射线衍射(XRD)、N2吸附脱附和透射电子显微镜(TEM)对催化剂进行表征,结果表明稀土的加入增加了负载过渡金属的氧化铝的比表面积,使孔道结构更加规则有序。程序升温脱附(TPD)、程序升温还原(TPR)、X射线光电子能谱(XPS)和27Al固体核磁共振(27Al MAS NMR)的表征进一步说明稀土金属和过渡金属对载体表面性质和Al配位的影响,在催化反应中铬是主催化剂,钕是助催化剂。将催化剂用于苯一步氧化制备苯酚的反应中,反应结果表明所得催化剂均具有较高活性,并且Nd-Cr/Al2O3的催化活性高于Cr/Al2O3。

Promoting Effect of Neodymium on Catalytic Reaction of Oxidation Benzene to Phenol

Nd-Cr/Al2O3 catalyst was synthesized by the sol-gel method.The catalysts were characterized by XRD,BET and TEM.The results showed that the specific surface area of the loading of transition metal onto aluminum oxide was increased due to the addition of the rare earth.The characterization of the sample of TPR,TPD,XPS,and 27Al MAS NMR indicated that the surface acidity and Al coordination of support were affected by the transition metal and the rare earth.Chromium in the catalytic reaction took major part.Neodymium in the catalyst had synergistic effect.The Nd-Cr/Al2O3 revealed better catalytic activity than Cr/Al2O3 in the direct oxidation of benzene to phenol.