锌铝复合氧化物负载镍基催化剂催化木质素高效加氢解聚研究

STUDY ON HIGH EFFICIENCY HYDROGENATION DEPOLYMERIZATION OF LIGNIN CATALYZED BY ZnO-Al_2O_3 COMPOSITE OXIDE SUPPORTED NICKEL

通过水热法合成了一系列Ni/ZnO-Al_2O_3催化剂,用于催化木质素解聚。采用X射线衍射(XRD),透射电镜(TEM),氢气程序升温还原(H_2-TPR)对催化剂理化性质进行分析。结果表明:金属镍颗粒能够均匀地分散在载体表面。在催化木质素加氢解聚过程中,载体锌铝比为3∶1的催化剂表现出较好的催化效果,使得有机溶剂木质素在200℃,2.5 MPa初始氢压的条件下转化率达到了94.5%,芳香族单体的收率达到了14.7%,结焦11%;催化剂在四次循环使用后仍能使木质素的转化率达到83.7%。

A series of Ni/ZnO-Al2O3 catalysts were synthesized by hydrothermal method to catalyze the depolymerization of lignin.The physicochemical property of catalysts were characterized by Powder X-ray diffraction,Hydrogen temperature programmed reduction and Transmission electron microscopy.The result show that nickel particles are uniformly dispersed on the surface of the support.When the lignin was used to determine the efficiency of the catalysts in methanol solvent,the Ni/ZnO Al2O3-3(the atomic ratio of Zn and Al was 3∶1)achieved the highest conversion(94.5%,which include 14.7%aromatic monomer and 11.0%coke)at 200℃under 2.5 MPa H2 for 4 h,the conversion of lignin could reach 83.7%after four runs.