阴离子或配体对乙炔氢氯化催化剂催化活性的影响.doc

阴离子或配体对乙炔氢氯化催化剂催化活性的影响 摘要 采用浸渍法制备了以活性炭为载体，金、银、铋的磷酸盐及配合物为活性组分的无汞催化剂，考察了该催化剂用于乙炔氢氯化反应合成氯乙烯的催化性能，并运用X射线衍射（XRD）、扫描电子显微镜(SEM)、比表面积（BET）和热重分析（TG）等表征手段对以银的磷酸盐及银氨络合物为前驱体的两种催化剂表征结果进行分析。 实验结果表明，单组分催化剂以含金催化剂的催化活性最好，含银催化剂次之，含铋催化剂活性最差。然而，三种金属的配合物较其磷酸盐催化剂的催化活性差别最大的是含银催化剂。以银氨络合物为前驱体制成的催化剂的乙炔转化率较Ag3O4/C催化剂显著提高，而氯乙烯的选择性几乎都在95%以上。 鉴于这种显著差别，着重对含银催化剂进行表征及分析。分析结果表明，不管催化性能测定前Ag以何种形式存在，经过乙炔氢氯化反应后，催化剂中均只存在氯化银单一物相，这与活化后催化剂中Ag的存在形式一致，说明催化剂的活性组分是AgCl。两种含银催化剂的巨大的比表面差距是导致催化活性不同的主要原因之一。积炭也是影响含银催化剂催化活性差别的因素之一。 关键词：乙炔;氢氯化;氯乙烯；非汞催化剂；配合物 Effects of Anions or Legend on the Catalytic Activity of Catalysts for Hydro chlorination of Acetylene FuYan HuRuisheng Abstract: The non-mercury novel catalysts with metal chlorides and metal phosphates based on actived carbon were prepared by dipping method and used in catalytic hydro chlorination of acetylene to vinyl chloride. Silver phosphate and silver ammonia complex as precursors of the two catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), specific surface area (BET) and thermal gravimetric analysis (TG). Experimental results showed that the catalytic activity of gold catalyst for the single component catalysts was the best, followed by silver catalyst; the catalytic activity of bismuth was the worst. However, the biggest difference between the three kinds of metal complexes to its phosphates catalytic activity was silver catalyst. The acetylene conversion rate of catalyst whose precursor is silver ammonia complex increased significantly than Ag3PO4 / C catalyst, while the selectivity of vinyl chloride are almost all above 95%. Given this significant difference, silver catalysts were characterized and analyzed. The results show that, regardless of what form the pre-determination of catalytic properties of Ag is in, after reaction, the catalysts were there only a single phase of silver chloride, which is