铜-腐植酸催化剂制备及催化苯甲醇氧化

Preparation of copper-humic acid catalyst and catalytic oxidation of benzyl alcohol

以褐煤中提取的腐植酸为原料,利用水热法制备铜-腐植酸催化剂(Cu-HAs),并对催化剂结构进行FTIR、XRD、XPS、SEM表征,将此催化剂用于催化苯甲醇氧化反应。对催化剂的制备条件如一水醋酸铜与腐植酸比例、老化温度、老化时间等进行考察,探讨了不同反应条件对铜-腐植酸催化剂催化苯甲醇氧化反应的活性影响。结果表明,此催化剂在制备温度30℃、老化时间3 h下具有较好的催化活性,苯甲醇转化率71%、苯甲醛产率68.6%;提升反应温度至110℃、反应时间3 h时,苯甲醇的转化率可达到91.3%、苯甲醛产率可达到87.8%。对该催化剂循环使用性及底物普适性考察,发现铜-腐植酸催化剂经过6次循环后,产率和转化率基本保持不变,催化剂能重复使用,具有良好的循环稳定性,所制备催化剂能够催化不同结构醇选择性氧化,在优化条件下产率均达到90%以上。

Using humic acid extracted from lignite as raw material,a copper-humic acid catalyst(Cu-HAs)was prepared by hydrothermal method,and the structure of the catalyst was characterized by FTIR,XRD,XPS,and SEM.The catalyst was used to catalyze the oxidation of benzyl alcohol.The preparation conditions of the catalyst,such as the ratio of copper acetate monohydrate to humic acid,aging temperature,aging time,etc.,were investigated,and the effects of different reaction conditions on the catalytic activity of the copper-humic acid catalyst for the oxidation of benzyl alcohol were discussed.The results show that the catalyst has good catalytic activity under the conditions of temperature 30℃and aging time 3 h.The conversion of benzyl alcohol is 71%and the yield of benzaldehyde is 68.6%.When the reaction temperature increases to 110℃and the reaction time is prolonged to 3 h,the conversion of benzyl alcohol can reach to 91.3%,and the yield of benzaldehyde can reach to 87.8%.The recyclability of the catalyst and the general applicability for different substrates were also investigated.The results shows that the yield and conversion of Cu-humic acid catalyst remain basically unchanged after 6 cycles,indicating that the catalyst can be reused and have good stability.The prepared catalyst can catalyze the selective oxidation of alcohols with different structures,and the yields can reach more than 90%for the different substrates under the optimized conditions.