钌基类石墨相氮化碳材料催化苯甲醇氧化

Catalytic oxidation of benzyl alcohol by Ru supported on g-C3N4

将RuCl3负载到类石墨相氮化碳(g-C3N4)纳米片上,在氮气气氛下450℃热还原,制备了Ru/g-C3N4(n)催化剂。通过X射线衍射表征分析发现,Ru/g-C3N4(n)催化剂在经过负载和热还原过程后,有效保存了g-C3N4 结构,并将RuCl3还原成钌单质;由透射电镜以及物理吸附表征可以观察到钌纳米粒子粒径为2~5nm、分布比较均匀、比表面积可达134m^2/g,并且在CO2 气氛下做化学吸附可以看到其明显的吸收峰,说明其存在大量碱性位。Ru/g-C3N4(n)催化剂无碱条件下催化苯甲醇氧化表现出优异的性能,苯甲醛的选择性达到96.8%,说明制备的Ru/g-C3N4(n)催化剂具有钌粒子较小、分布均匀、比表面积大以及碱性位含量高等特点有利于提高催化剂的催化活性。

Ru/g-C3N4(n) catalyst was prepared by direct reduction of a ruthenium trichloride on graphitic carbon nitride (g-C3N4) nanosheets at 450 ℃ in N 2. X ray diffraction analysis indicated that the Ru/g-C3N4(n) catalyst has effectively preserved the structure of g-C3N4 and reduced ruthenium trichloride to Ru^0 after the loading and thermal reduction process. The observation of TEM and N2 adsorption-desorption isotherms showed that the particle size of ruthenium nanoparticles was about 2-5 nm, the distribution was uniform and the surface area of the catalyst could reach to 134m^2/g. Furthermore, the chemical adsorption under CO2 atmosphere showed obvious absorption peak, indicating that it has a large number of basic sites. Ru/g-C3N4(n) achieved high yields of benzaldehyde (96.8%) for the catalytic oxidative of benzyl alcohol without basic additive. It showed that small particle size, equally distribution, high amounts of base sites of Ru/g-C3N4(n) catalyst are beneficial for improving catalytic activity.