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采用等体积浸渍法制备了一系列不同载体负载Zn(OAc)_2催化剂,用于1,6-己二胺(HDA)与碳酸二甲酯(DMC)反应制备1,6-六亚甲基二氨基甲酸甲酯(HDC)。通过X射线粉末衍射(XRD),N_2物理吸附(BET),NH_3程序升温脱附(NH_3-TPD),热重分析(TG-DTG),傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)对催化剂进行了表征,结果表明,硅胶负载Zn(OAc)_2催化剂上Si—O—Zn键的形成有利于DMC的活化,表面酸性位促进了碱性HDA的活化,从而使其具有最佳催化活性。在反应温度80℃、反应时间6 h、DMC/HDA摩尔比2∶1、催化剂用量n〔Zn(OAc)_2〕∶n(HDA)=0.02∶1的条件下,HDA转化率为96.0%,HDC收率可达68.5%,催化剂具有良好的稳定性,循环利用5次后活性无明显下降。
A series of different support supported Zn (OAc) 2 catalysts were prepared by the same volume impregnation method for the reaction of 1,6-hexamethylenediamine (HDA) and dimethyl carbonate (DMC) Methyl Carbamate (HDC). XRD, BET, NH_3-TPD, TG-DTG, FTIR and X-ray photoelectron energies were investigated by X-ray powder diffraction (XRD) The results showed that the formation of Si-O-Zn bond on the silica supported Zn (OAc) 2 catalyst was favorable for the activation of DMC. The surface acid sites promoted the activation of basic HDA, Has the best catalytic activity. The HDA conversion was 96.0% under the conditions of reaction temperature 80 ℃, reaction time 6 h, molar ratio of DMC to HDA 2:1, catalyst amount n (Zn (OAc) 2): n (HDA) HDC yield up to 68.5%, the catalyst has good stability, no significant reduction in activity after 5 cycles.