Co-Ru/HAP的制备及其催化乙二醇氨化反应

Preparation of a Co-Ru/HAP catalyst and its catalytic performance for ethylene glycol amination

为提高乙二醇氨化反应中乙二胺的选择性,以羟基磷灰石(HAP)为载体、Co为主活性组分,引入第二金属组分制备了一系列负载型双金属催化剂。结果表明,Co-Ru/HAP催化效果较优,适宜制备条件为:制备HAP的pH值为10、金属总质量分数为9%、Co与Ru质量比m(Co):m(Ru)为10:1、还原温度为500℃。此时,乙二醇转化率为30.2%,乙二胺选择性为35.4%,乙二胺和乙醇胺选择性之和为58.0%。结合催化剂表征和活性评价结果可知,金属Co主要促进氨化过程中脱氢和加氢步骤,而金属Ru主要是抑制NH3在金属Co表面的吸附,以保证有较多的Co金属位活化乙二醇;催化剂的酸碱活性位点存在明显的协同作用。采用气相色谱-质谱联用技术对乙二醇氨化反应液进行了定性分析,在此基础上,建立了Co-Ru/HAP催化乙二醇氨化的反应网络。

A series of supported bimetallic catalysts were prepared by introducing different second metal components into Co/HAP to improve ethylenediamine selectivity in ethylene glycol amination.Co-Ru/HAP showed better catalytic performance and its preparation conditions were obtained as follows:pH=10,metal loading=9%,mass ratio of Co to Ru=10:1 and reduction temperature=500℃.The conversion of ethylene glycol was 30.2%under these conditions.Ethylenediamine selectivity and total ethylenediamine and ethanolamine selectivity were 35.4%and 58.0%,respectively.Combined with catalyst characterization and activity evaluation,the results show that Co mainly facilitates dehydrogenation and hydrogenation steps in ethylene glycol amination,while Ru mainly inhibits NH3 adsorption on the surface of Co,which can ensure more Co sites to activate ethylene glycol.The acid-base active sites of the catalyst have an obvious synergistic effect.A qualitative analysis of ethylene glycol amination was performed by gas chromatography-mass spectrometry analysis,and the reaction network of Co-Ru/HAP catalyzed ethylene glycol amination was established.