Cu/ZrO_2催化二乙醇胺氧化脱氢制亚氨基二乙酸性能研究

Study of Cu/ZrO_2 catalyst for oxidation dehydrogenation from diethanolamine to iminodiacetic acid

采用共沉淀法制备了Cu/ZrO2催化剂,考察了反应物料对二乙醇胺氧化脱氢制亚氨基二乙酸(IDA)反应中催化剂性能的影响.采用X射线衍射(XRD)、扫描电镜-能谱分析(SEM-EDS)和N2吸附-脱附等手段考察了催化剂反应前后的结构特征及表面性能.结果表明:催化剂在循环使用过程中的结构改变是造成催化活性下降的主要因素.反应物料氢氧化钠促使亚稳态ZrO2载体向四方相转变,加剧了非晶态活性Cu(0)的晶化,进而影响活性组分Cu(0)与载体的相互作用,进一步加快了活性组分Cu(0)颗粒的长大,导致催化剂的活性下降.

Cu-zirconia catalyst was prepared by coprecipitation and tested for oxidation dehydrogenation from diethanolamine to iminodiacetic acid. The results showed that the catalytic activity was influenced by the reaction material. Techniques of XRD, SEM-EDS and N2 adsorption-desorption was used to characterize the structure and surface properties of the catalyst. The results showed that the structual changes of the catalyst was the major factor of deactivation in the reaction process. The sodium hydroxide accelerated the crystallization of catalyst and weakened the interaction between copper and zirconia, which resulted in copper particles growing up and catalytic activity decreasing.