碳纳米纤维的酸处理及其负载Pd-Pt的催化萘加氢活性

采用浓硝酸和浓硫酸混和液(90、120、150 ℃)处理鱼骨类和平行类碳层排布的碳纳米纤维. 运用高分辨电镜、红外光谱和离子交换对碳纳米纤维的表面性质进行了表征，并考察了以两种碳纳米纤维为载体的Pd-Pt催化萘加氢活性. 结果表明，碳纳米纤维的碳层排布不同使混酸处理的鱼骨类表面生成的极性含氧基团的量明显高于平行类表面，以前者为载体得到Pd-Pt催化剂金属颗粒的分散程度明显高于后者，其负载的Pd-Pt催化萘加氢活性也较高.

Treatment of the Carbon Nanofiber Surfaces in Mixed Concentrated HNO3-H2SO4 and the Catalytic Activity of Supported Pd-Pt for Naphthalene Hydrogenation

Catalytically grown carbon nanofibers with different carbon layer arrangements, fishbone-shaped and parallel, were treated in a mixture of concentrated nitric and sulfuric acids (90, 120, 150 ℃) to introduce the oxygen-containing surface functional groups. The surface properties were characterized with high-resolution electron microscope, FT-IR, and ion-exchange method. The results showed that much more oxygen-containing groups were formed on the fishbone surface shaped of carbon nanofibers than those on the parallel type surface in the mixed acids treatment. This tendency became pronounced with the increase of treatment temperatures. When the treated CNFs were used as the carrier of Pd-Pt metal catalysts, it was found that the interaction became stronger between the supported metals and the carbon nanofibers with the increase of the concentration of the surface oxygen-containing groups. The activity of the supported catalyst on the carbon nanofibers of the fishbone type was much higher than that on the parallel type for the hydrogenation of naphthalene to tetralin.