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对多壁碳纳米管进行纯化和功能化处理,比较了未氧化处理与经浓硝酸和浓硫酸混酸(浓硫酸与浓硝酸体积比为3∶1)处理后的不同多壁碳纳米管(MWCNTs)为载体的Pd催化剂(Pd/MWCNTs)的分散性和粒径。利用X线粉末衍射仪(XRD)、透射电镜(TEM)、X射线能谱(EDS)和傅里叶变换红外光谱仪(FT-IR)等测试手段对所得的样品进行了表征。结果表明,MWCNTs表面不修饰不利于金属Pd纳米粒子的沉积,混酸处理使MWCNTs表面有大量的含氧活性基团,能够促进负载的Pd纳米粒子均一分布,明显提高了苯甲醇氧化为苯甲醛的选择性和转化率。
Multiwalled carbon nanotubes (MWCNTs) were purified and functionalized. The effects of non-oxidative treatment and mixed multi-walled carbon nanotubes (MWCNTs) treated with concentrated nitric acid and concentrated sulfuric acid (3: 1 by volume ratio of concentrated sulfuric acid to concentrated nitric acid) ) Pd catalyst (Pd / MWCNTs) dispersion and particle size. The obtained samples were characterized by XRD, TEM, EDS and Fourier transform infrared spectroscopy (FT-IR). The results showed that the surface modification of MWCNTs was not conducive to the deposition of Pd nanoparticles. The mixed acid treatment provided a large number of oxygen-containing active groups on the surface of MWCNTs, which promoted the uniform distribution of Pd nanoparticles and significantly enhanced the oxidation of benzyl alcohol to benzaldehyde Selectivity and conversion rate.