介孔钨铝复合氧化物载铂催化剂催化甘油氢解反应

Hydrogenolysis of glycerol over mesoporous tungsten-aluminum mixed oxides supported platinum catalyst

以Al(OH)_3为铝源,用分步浸渍-焙烧法制备介孔钨铝复合氧化物负载铂催化剂。在连续流动固定床反应器中,考察催化剂催化甘油氢解制备1,3-丙二醇(1,3-PDO)的催化性能与稳定性。通过N2物理吸附、X线衍射(XRD)方法表征反应前后催化剂的结构。结果表明:介孔钨铝复合氧化物负载铂催化剂的平均孔径为16 nm,催化剂在甘油氢解反应中呈现良好的催化活性。催化剂焙烧温度、反应温度、甘油质量空速(WHSV)及甘油水溶液浓度等因素变化对1,3-丙二醇产率及甘油转化率有较大影响。在160℃、4 MPa、60%甘油水溶液进料、甘油质量空速为0.25 h^(-1)、H_2与甘油摩尔比为100∶1的条件下,介孔钨铝复合氧化物负载铂催化剂催化甘油氢解反应,甘油转化率为54.1%,1,3-丙二醇的产率与选择性分别为26.2%与50.3%。催化剂长期稳定性良好。

The catalysts of platinum supported mesoporous tungsten-aluminum mixed oxides which used Al(OH)3as aluminum source precursor were prepared by the method of stepwise impregnation-calcination.The catalytic performance and stability of the catalysts which catalyze hydrogenolysis of glycerol to1,3-propanediol(1,3-PDO)were performed in a continuous flow fixed-bed reactor.The physico-chemical properties of the catalysts were characterized by the techniques of N2physical adsorption,X-ray diffraction(XRD).Results showed that the catalysts had stable mesoporous structure and exhibited excellent catalytic activity in the reaction of hydrogenolysis of glycerol.The catalyst calcination temperature,reaction temperature,weight hourly space velocity(WHSV)of glycerol and glycerol concentration had a impact on the yield of1,3-propanediol and glycerol conversion.Under the conditions of160℃,4MPa,60%glycerol aqueous solution with WHSV of0.25h-1,n(H2)/n(glycerol)=100∶1,hydrogenolysis conversion on the mesoporous catalyst was up to54.1%,and1,3-propanediol yield and selectivity were26.2%and50.3%,respectively.The mesoporous catalyst exhibited excellent long term stability and durability.