表面改性杂多酸衍生CoMoS催化剂的制备及其蒽加氢性能

Preparation of CoMoS Catalyst Derived From Surface-Modified Polyoxometalate and Its Catalytic Performance for Anthracene Hydrogenation

引入亚纳米尺寸的Co-Mo杂多酸,并采用表面活性剂对杂多酸进行表面改性,进而制备得到S-Co_(2)Mo_(10)@DODA催化剂。采用XRD、FT-IR、TG、XPS和TEM等表征手段对催化剂的组成和结构进行分析。结果表明:改性杂多酸具有极其优异的油溶性,可单分子分散在有机溶剂中,且易硫化。与油溶性有机Co-Mo催化剂相比,硫化后S-Co_(2)Mo_(10)@DODA催化剂片层尺寸小,堆积层数少,分散度高,可暴露更多的边角活性位;同时,硫化度高,含有更高比例的CoMoS活性相。当反应温度为400℃、氢初压为7 MPa、反应时间为1 h时,S-Co_(2)Mo_(10)@DODA催化蒽加氢反应转化率达到100%,深度加氢产物(八氢蒽+全氢蒽)选择性达到84.3%。

S-Co_(2)Mo_(10)@DODA catalyst was prepared by introducing sub-nanometer Co-Mo polyoxometalate,of which surface was modified by surfactant.The composition and structure of the catalyst were analyzed by multiple characterization means,such as XRD,FT-IR,TG,XPS and TEM.The results demonstrate that the modified polyoxometalte has excellent oil-solubility,which can be dispersed in organic solvents as single molecules and is easy to be vulcanized.Compared with the oil-soluble organic CoMo catalyst,the S-Co_(2)Mo_(10)@DODA catalyst after being vulcanized has the characteristics of small nanosheet size,small stacking layer number and high dispersion degree,which may expose more edge and corner active sites.Meanwhile,it is highly vulcanized and has a higher proportion of CoMoS active phases.When the reaction temperature is 400℃,the initial hydrogen pressure is 7 MPa,and the reaction time is 1 h,the conversion rate of anthracene hydrogenation reaction can reach 100%,and the selectivity of the deep hydrogenation products(octahydroanthracene and perhydroanthracene)is up to 84.3%.