锰和镧助剂对二乙醇胺氧化脱氢制亚氨基二乙酸Cu/ZrO_2催化剂的改性作用

Effect of Mn and La Modified Cu/ZrO_2 Catalyst for Oxidation Dehydrogenation from Diethanolamine to Iminodiacetic Acid

采用共沉淀法制备了掺杂锰、镧的Cu/ZrO2催化剂,考察了锰和镧助剂对Cu/ZrO2催化二乙醇胺氧化脱氢制亚氨基二乙酸性能的影响。采用XRD(X射线粉末衍射),TPR(程序升温还原),N2O滴定,N2吸附-脱附等方法考察了助剂改性后催化剂的结构和表面性质的变化。结果表明,引入锰助剂后催化剂比表面积从105 m2.g-1增大到143 m2.g-1,活性Cu的分散度从36.5%提高到53.6%;镧助剂的引入阻滞了金属Cu的聚集长大,延缓了催化剂晶化速度;锰、镧共同引入时表现出协同作用,不但使活性Cu的分散度提高,同时催化剂晶化速度减慢,从而提高了催化剂循环使用性能。

A series of Cu-zirconia catalysts containing additives（Mn,La） was prepared by method of coprecipitation,and the effect of the accessory ingredients（Mn,La） on the catalytic performance during the dehydrogenation oxidation from diethanolamine to iminodiacetic acid was investigated.The structure and surface properties of the modified catalysts were investigated by means of X-ray powder diffraction（XRD）,temperature programmed reduction（TPR）,N2O titration and N2 adsorption-desorption techniques.The results show that the additive of Mn could increase the surface area of catalyst from 105 m2·g-1 to 143 m2·g-1 and the dispersion degrees of copper species from 36.5% to 53.6%;while La could block Cu particles′conglomeration and suppress the crystallization of the catalysts.The catalytic performance of La and Mn co-modified catalysts was greatly improved,demonstrating a synergistic effect.