Research Of Cu-based Catalysts For Diethanolamine Dehydrogenation And Its Raw Material Analysis

Iminodiacetic acid（IDA）,an important platform chemical in agriculture,environmental treatment and electroplating,particularly is used to produce universal herbicide,glyphosate.For the production of glyphosate,dehydrogenation of diethanolamine（DEA）is a burgeoning intermediate production technique invented by Monsanto to produce iminodiacetic acid（salt）（DSIDA/IDA）and has drawn more attention.The multifunctional copper-based nanocatalyst as a promising catalyst for this reaction and some pioneering progresses have been conducted in a series of Cu NPs supported on nanoscale oxide supports.However,catalysts usually suffer from sintering and leaching to deactivation,which impedes its industrial application.Therefore,it is necessary but still a great challenge to design highly active and stable catalysts over diethanolamine dehydrogenation.Moreover,the analysis of diethanolamine in complex matrix samples is still faint,it has also attracted much attention in the field of environmental science.Herein,this paper were carried out in parallel from the following aspects:（1）A simple one-pot precipitation-impregnation strategy was proposed toward B_xCu ZrO₂ as a highly active,selective and stable catalyst for dehydrogenation reaction of diethanolamine.An IDA yield of 96.7%is achieved over B₁Cu ZrO₂ with a diethanolamine conversion of 99.1%,1.25 times that of Cu ZrO₂.Even after 8 loop tests,B₁Cu ZrO₂ exhibits good stability.Based on catalytic results and comprehensive characterization,the incorporation of an appropriate amount of B₂O₃is more favorable for inhibiting the agglomeration,sintering and leaching of the active component Cu,which providing a sustainable and more economically competitive technical support for the dehydrogenation of diethanolamine to iminodiacetic acid.（2）A facile thermal treatment method was proposed to construct Cu Co bimetallic catalyst decorated on B,N co-doped porous carbon polyhedron.Using ZIF-67 as sacrificial template,pre-synthesized Cu²⁺/ZIF-67 through two in the staged high-temperature pyrolysis procedure,the porous C support generated by the pyrolysis of ZIF-67 is doped with B element to generate the Cu Co@BCN.Compared with Cu ZrO₂and Co@BCN,Cu Co@BCN displays higher activity performance,yielding the desired product in up to 92.16%in the first time.And the contribution of structural and two-component synergistic to improving catalytic activity was determined by comprehensive characterization techniques.（3）A pre-column derivatized HPLC-MS analytical method using FMOC-Cl as a derivatizing agent was established for ultra-fast detection of low-content alkanolamines in complex matrices,and applied to the diethanolamine（DEA）dehydrogenation reaction.The chromatographic separation conditions and derivatization reaction conditions were optimized.In this method,the spiked recoveries of monoethanolamine（MEA）and diethanolamine（DEA）ranged from 95.22%to 104.64%and 91.25%to107.69%,respectively,and the relative standard deviations（RSD）ranged from 3.86%to 4.42%and 2.87%to 3.77%,respectively.This is a simple and rapid analytical method with excellent accuracy and repeatability.