Preparation And Study Of Cu/ZrO₂ Catalyst In The Dehydrogenation From Diethanolamine To Iminodiacetic Salt

Iminodiacetic salt is a kind of organic intermediate with many applications, especially there is great demand in the preparation of glyphosate. At the same time there are many preparation methods. The method of dehydrogenation of diethanolamine by catalysis is litte pollution, low cost, high yield. it is a kind of method with great prospect.This paper is about the study of catalyst used in the dehydrogenation from diethanolamine to Iminodiacetic salt. After analyzing the reaction mechanism through literature, we think the reaction from diethanolamine to iminodiatic salt is composed of two steps—reaction from alcohol to aldehyde and the disproportionation reaction of the aldehyde. The selectivity, conversion, rate of this reaction are mainly attributed to the capability of this catalyst. we use co-precipitation method to prepare the Cu/ZrO2 catalyst; Through the orthogonal design experiment and pricipal component experiment,we get the best production condition of catalyst preparation: C(Zr)=0.3 mol/L, NZr/NCu=2, pH=2, calcination for 4h at 500℃, reduction for 4h at 230℃；In the test of the catalyst capability, through the pricipal component experiment. We get the best production condition of dehydrogenation reaction by catalysis: the temperature at 165℃, the pressure at 1.6MPa, 30％(quality percentage) sodium hydroxide solution; At last, we characterize the catalyst through BET ,XRD, SEM. we can know the catalyst is a kind of irregular and massive particles with 6～15μｍ particle diameter and 116.53 m2/g BET surface area, the carrier ZrO2 of this catalyst is nanocrystalline. In the dehydrogenation from diethanolamine to Iminodiacetic salt, when the quality of catalyst is 20%( quality percentage) of diethanolamine quality, the product yield can be up to 96.6% in 2.1 hours at first reaction, the average yield is 87.8% in 9 repeat reaction.