锰和镧助剂对二乙醇胺氧化脱氢制亚氨基二乙酸Cu/ZrO2催化剂的改性作用

Effect of Mn and La Modified Cu/ZrO2 Catalyst for Oxidation Dehydrogenation From Diethanolamine to Iminodiacetic Acid

摘要:

采用共沉淀法制备了锰、镧掺杂的Cu/ZrO2催化剂，考察了锰和镧助剂对Cu/ZrO2催化剂二乙醇胺氧化脱氢生成亚氨基二乙酸催化性能的影响。 采用XRD(X射线粉末衍射)，TPR(程序升温还原)，N2O滴定，N2吸附-脱附等手段考察了助剂改性后催化剂的结构和表面性质的变化。研究结果表明：掺杂锰后催化剂比表面积从掺杂前的105 m2?g-1增大到143 m2?g-1，活性铜物种的分散度从掺杂前的36.5%增大到53.6%；镧的掺杂阻滞了金属Cu的聚集长大，延缓了催化剂晶化速度；锰、镧同掺杂时，由于锰、镧的协同作用，不但使得活性铜物种的分散度提高，同时催化剂晶化速度减慢，是催化剂性能提高的原因。

Abstract:

A series of Cu–zirconia catalysts containing additives (Mn, La) were prepared by coprecipitation and tested for dehydrogenation oxidation from diethanolamine to iminodiacetic acid. The structure and surface properties of the catalysts were characterized by X-ray powder diffraction (XRD), temperature programmed reduction (TPR), N2O titration and N2 adsorption-desorption techniques. The results showed that the addition of Mn could increase the surface area of catalyst from 105 m2?g-1 to 143 m2?g-1and the dispersion degrees of copper species from 36.5% to 53.6%; The addition of La could inhibit Cu particle from growing up and suppress the crystallization of the catalysts; The catalytic performances of the catalysts were greately improved by the addition of Mn and La together. A synergistic effect in La and Mn co-modified Cu/ZrO2 catalyst was suggested.