Abstract: Cu-Cr₂O₃ catalysts were prepared by the coprecipitation method.The effect of Cu content on catalytic performance for hydrogenation of methyl difluoroacetate to 2,2-difluoroethanol was investigated.The catalysts were characterized with XRD, H₂-TPR, BET and Raman techniques.The results showed that the reduced Cu-Cr₂O₃ catalysts contained mainly Cu and Cr₂O₃, while catalysts with a high Cu content (e.g.30 Cu-Cr₂O₃ and 50 Cu-Cr₂O₃) contained CuCr₂O₄ and CuCrO₂ oxides.It was also found that with increasing Cu content, conversion of methyl difluoroacetate first increased and then slightly decreased and selectivity to 2,2-difluoroethanol was about 70%.The 30Cu-Cr₂O₃ catalyst exhibited the highest conversion of 97%.In addition, conversion of methyl difluoroacetate increased gradually in bi-component Cu-Cr₂O₃ catalysts with increasing Cu content, which was probably due to the presence of CuCr₂O₄ and CuCrO₂ oxides.

Key words: methyl difluoroacetate, hydrogenation, 2,2-difluoroethanol, Cr₂O₃, Cu

摘要： 采用共沉淀法制备了Cu-Cr₂O₃催化剂,考察了铜含量对Cu-Cr₂O₃催化剂的二氟乙酸甲酯加氢合成二氟乙醇性能的影响。运用X射线衍射(XRD)、程序升温还原(TPR)、BET和Raman光谱技术对该催化剂进行了表征。结果表明,还原态Cu-Cr₂O₃催化剂物相主要由Cu和Cr₂O₃组成,然而30Cu-Cr₂O₃和50Cu-Cr₂O₃催化剂存在少量CuCr₂O₄和CuCrO₂复合氧化物。随着铜含量的增加,Cu-Cr₂O₃催化剂的二氟乙酸甲酯单程转化率呈现先上升后下降的趋势,而二氟乙醇选择性保持在70%左右; 30Cu-Cr₂O₃催化剂的二氟乙酸甲酯单程转化率达到最大值97%。Cu-Cr₂O₃催化剂的二氟乙酸甲酯加氢反应比速率随着铜含量的增加呈现增大的趋势,反应比速率的提高可能与催化剂中CuCr₂O₄和CuCrO₂物种的存在有关。

关键词: 二氟乙酸甲酯, 加氢, 二氟乙醇, Cr₂O₃, Cu