Cu/SiO_2两步法催化甘油氢解制备1,2-丙二醇

摘要

采用两步法从甘油制备1,2-丙二醇,首先甘油在催化剂上进行脱水反应生成丙酮醇,然后丙酮醇在催化剂上进行加氢反应生成1,2-丙二醇。两个反应应用的催化剂都是采用浸渍法制备的Cu/SiO2催化剂。催化剂制备简单,成本较低且绿色无污染。结果表明：加氢反应在反应温度为180℃,催化剂相对原料用量为10%,反应时间为30 h,反应压力为4 MPa,10%Cu负载量的催化剂上具有最高的转化率（〉96%）和选择性（〉96%）。该催化剂为双功能催化剂既具有酸中心又具有金属活性位点。研究结果表明催化剂上单质铜粒径的大小是影%1,2-propanediol was prepared by hydrogenolysis of glycerol in two steps.Firstly,glycerol was dehydrated over bi-functional catalyst Cu/SiO2 into acetol,which was in turn hydrogenated into 1,2-propanediol over the same catalyst.The catalyst Cu/ SiO2 was prepared,by the coprecipitation method.The catalyst preparation was simple,of low cost,and environmentally friendly.The prepared catalyst was characterized with BET and XRD.The result indicated that the prepared catalyst had comparatively high activity.The best conversion（96%）and selectivity（96%）performance of the catalyst was achieved when the Cu loading amount was 10%.This bi-functional catalyst possessed acid site and metal active site as well.The particle size of Cu was the major factor to influence the activity of the catalyst.Deactivation of the catalyst was attributed to interaction of the copper species on the catalyst surface and the carrier,which caused aggregation of the active species.