Pt/WO_(x)/Al_(2)O_(3)及其改性催化剂氢解甘油制备1,3-丙二醇

Preparation of 1,3-propanediol by hydrogenolysis of glycerol over Pt/WO_(x)/Al_(2)O_(3) and its modified catalysts

为了研究催化剂组分对甘油氢解制备1,3-丙二醇(1,3-PDO)反应过程的影响,实验选用拟薄水铝石作为催化剂载体,通过饱和浸渍法制备了大孔容、高比表面积的Pt/WO_(x)/Al_(2)O_(3)催化剂,并通过添加Fe、Mn和Ru对催化剂进行了改性。结果表明,在170℃、9 MPa条件下,2Pt/30WO_(x)/Al_(2)O_(3)催化反应6 h,甘油转化率为21.2%,1,3-丙二醇选择性为58.9%。Pt/WO_(x)/Al_(2)O_(3)催化剂在甘油氢解反应中的活性主要由催化剂表面Pt活性位点数量控制。对于Pt/WO_(x)/Al_(2)O_(3)催化剂的改性,反应6 h后,Ru的添加使1,3-PDO的产率提高了60%,而Fe、Mn的添加则无明显的提升效果。通过表征发现,催化剂上负载的WO_(x)、Pt和Ru均匀分散在载体上;催化剂上的弱酸和中强度酸有利于提高甘油氢解制备1,3-PDO的选择性。

To study the effect of catalyst components on the hydrogenolysis of glycerol to 1,3-propanediol(1,3-PDO),the pseudo-boehmite was chosen as the catalyst support.The Pt/WO_(x)/Al_(2)O_(3) catalysts with large pore capacity and high specific surface area were prepared by saturation impregnation method.The catalysts were also modified by the addition of Fe,Mn and Ru.The results show that the glycerol conversion is 21.2% and the 1,3-propanediol selectivity is 58.9%with the catalysis of 2Pt/30WO_(x)/Al_(2)O_(3) for 6 h at 170℃ under 9 MPa.The activity of the Pt/WO_(x)/Al_(2)O_(3) catalyst in the glycerol hydrogenolysis reaction is mainly controlled by the amount of Pt active sites on the catalyst surface.For the modification of Pt/WO_(x)/Al_(2)O_(3) catalyst,the addition of Ru increases the yield of 1,3-PDO by 60% after 6 h of reaction,while the addition of Fe and Mn has no significant effect of enhancement.It is found that WO_(x),Pt and Ru supported on the catalyst are evenly dispersed on the support by characterization.The weak and neutral acids on the catalyst are favorable to improve the selectivity of glycerol hydrolysis to prepare 1,3-PDO.