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采用浸渍法和干混法制备了以TiO2为载体负载WO3的加氢精制催化剂,利用XRD分析了样品表面上钨的分散性。结果表明,通过浸渍法处理含低、中、高钨质量分数的催化剂,钨在载体TiO2表面上自发分散使晶相钨物种消失;而通过干混法热处理的催化剂,只有含钨质量分数的催化剂中钨自发分散使晶相钨物种消失,而含钨质量分数中、高的催化剂,其表面上均仍保留晶相钨物种,这就说明浸渍法制备的W/TiO2催化剂中钨的分散较好,而干混法制备的W/TiO2催化剂钨较难分散。对浸渍法与干混法制备的W/TiO2催化剂进行氨溶处理,可以使含低、中、高钨质量分数的催化剂上所有的晶相钨物种消失,即氨溶处理溶解掉部分表面钨物种,改善了钨物种在载体表面上的分散性。
The impregnation method and dry blending method were used to prepare the hydrotreating catalyst supported on TiO2 by using TiO2 as support. The dispersibility of tungsten on the sample surface was analyzed by XRD. The results show that the tungsten species with low, medium and high tungsten content are treated by impregnation to disperse tungsten spontaneously on the surface of TiO2 carrier, which results in the disappearance of crystalline tungsten species. However, only the tungsten-containing catalyst The spontaneous dispersion of tungsten causes the disappearance of the crystalline tungsten species, while the high and medium tungsten-containing catalysts retain the crystalline tungsten species on their surface, indicating the better dispersion of tungsten in the W / TiO2 catalyst prepared by impregnation , While W / TiO2 catalyst prepared by dry blending tungsten is more difficult to disperse. Ammonia treatment of W / TiO2 catalyst prepared by impregnation method and dry blending method can eliminate all crystalline tungsten species on the catalysts containing low, medium and high tungsten fractions, that is, ammonia solution dissolves some surface tungsten species , Improving the dispersibility of tungsten species on the support surface.