The Optimation,Characterization And Catalytic Performance Evaluation Of Co₃Mo₃N Catalyst For Fischer-tropsch Synthesis

FT synthesis,which was first reported by the German chemists Franz Fischer and Hans Tropsch and already has the history of one hundred years,has been made great progress.Under the current background of the growing global demand for liquid fuels and increasing environmental concerns,FT synthesis has received renewed interest in recent years.Among which,the development of high selectivity catalysts and study of the broken of Anderson-Schulz-Flory(ASF)distribution mechanism are researching hotspots currently.Because of the higher activity and stability,the bimetallic nitrides Co3Mo3N is considered as a sort of promising catalyst for FT synthesis.Herein,the focus of this work is to optimize the catalytic performance of Co3Mo3N catalyst on the basis of our previous work,further increasing the selectivity of C5+ and decreasing the selectivity of CH4.First,we reported a series of monometallic elements Zr,La and Mn dopped Co3Mo3N catalysts,which remarkably showed the increased catalytic activity.Moreover,the effects of doping elements on structure,morphology and particle size of samples were investigated by using XRD,XPS,SEM,HRTEM and EDS.Second,two SBA-15 supported Co3Mo3N catalysts were prepared through solid phase synthesis and equal volume impregnation methods,and were charaterized by XRD,HRTEM and EDS techniques.Meanwhile,their catalytic performance for FT synthesis was evaluated.The results showed that the solid phase synthesis method was better than the equal volume impregnation method.By combinating the data of NH3-TPR and the XRD patterns of Co3Mo3N under different nitridation temperature,the formation process of Co3Mo3N was studied.Moreover,the valence state and quantity of the inner elements of Co and Mo in Co3Mo3N catalyst were explored through XPS meamurements.