低温液相合成甲醇及甲酸甲酯用Cu-Cr-M-O催化剂的制备与表征

Preparation and Characterization of Cu Cr M O Catalyst for Synthesis of Methanol and Methyl Formate at Low Temperature in Slurry Phase

采用共沉淀法和配合物沉淀法制备了分别添加Ｂａ， Ｍｎ，Ｖ，Ｂｉ，Ｎｉ 和Ｚｎ 的ＣｕＣｒＭＯ三组分催化剂，采用ＢＥＴ，ＸＲＤ和ＴＥＭ 对催化剂进行了表征，并考察了其对合成甲醇及甲酸甲酯反应的活性及选择性． 结果表明，添加第三种金属使催化剂的稳定性及甲酸甲酯选择性有所提高，但使催化活性有所下降． 配合物沉淀法制备的催化剂的比表面积较大，粒径较小． 热分解温度越高，催化剂的比表面积越小． 除ＣｕＣｒＶＯ 催化剂为纳米非晶态之外，其它催化剂均呈晶态． 催化剂的最小平均粒径为３８ ｎｍ ， 最大平均粒径为６８ ｎｍ ， 属纳米级催化剂．

The Cu Cr catalyst modified with the third metal, such as Ba, Mn, V, Bi, Ni and Zn, was prepared by coprecipitation and complex precipitation methods respectively, and characterized by BET, XRD and TEM, and its activity as well as selectivity for methyl formate (MF) were measured. The results demonstrated that the third metal can elevate the MF selectivity and the stability of Cu Cr catalyst, but lower its catalytic activity. The catalyst prepared by complex precipitation has larger specific surface area and smaller particle diameter. The higher the thermal decomposition temperature, the less the specific surface area of the catalyst. Except that the Cu Cr V O is non crystalline, the other samples are crystalline and nanometric. The least particle diameter is 38 nm, and the largest particle diameter is 68 nm.The fact that the Cu Cr Mn O and Cu Cr V O have higher stability can be attributed to that the valence variable Mn and V can stabilize the active site Cu + because of their redox ability.