应用分析电子显微镜考察铂锡催化剂上的积炭

在高分散铂锡催化剂上分别以正丁烷,正己烷及长链烷烃为反应物经催化剂脱氢表面积炭。从电子显微镜图像观察到积炭有多种结构,最小的炭粒呈条纹排列,炭粒集聚形成球状炭黑及不同形状的石墨结晶。选区电子衍射分析炭(002)晶面间距有3.35～4.13A变化表明石墨化程度不同。三种积炭样品的电子能量损失谱相应地亦展示明显的差别。

Characterization of Carbon Deposition on Catalysts by Analytical Electron Microscopy

Three kinds of carbon-deposits which formed on Pt-Sn catalyst from dehydrogenation rea-ction of long-ceain paraffins, n-hexane and n-butane have been studied with analytical elec-tron microscopy. The electron micrographs obtained show several types of structure from dif-ferent fragments of coke. The smallest particles deposited in order and appeared to be fringe-like. The aggregates found may be formed from the fusion of small particles. The sphericalcarbon and the graphite-like carbon containing crystallites have also been observed. A varietyof graphite carbon built up on the catalyst. The electron diffration ring corresponding to spa-cing distance of (002) is different for various daposits. It varies from 3.35 to 4.13A. It sug-gests that they have been graphitized to various extent. The electron energy loss spectra of thethree kinds of carbon deposit also show obvious difference.