화학공학소재연구정보센터
Fuel, Vol.198, 145-158, 2017
Characterization and HDS activity of sulfided Co-Mo-W/SBA-16 catalysts: Effects of P addition and Mo/(Mo plus W) ratio
Two series of SBA-16-supported Co-Mo-W ternary sulfide catalysts with atomic ratio r = Mo/(Mo + W) ranging from 0.3 to 0.7 were prepared by the simultaneous impregnation of SBA-16 and phosphatedSBA- 16 substrates with metal precursors. The samples were characterized by a variety of techniques (chemical analysis, N-2 physisorption, SEM, XRD, DRS UV- vis, TPR, TPD-NH3, Raman spectroscopy, HRTEM, XPS and coke burning). The catalytic performance was evaluated in the hydrodesulphurization (HDS) of dibenzothiophene (DBT), carried out in a batch reactor at 350 degrees C and 3.1 MPa of total H-2 pressure. The maximum activity at the same atomic ratio r = 0.4 was observed for the catalysts supported on SBA-16 modified with phosphorous (r = 0.4(P)). HRTEM evidenced that this was because different MoS2 crystalline structures were formed: the P- free sample prepared with Mo/(Mo + W) atomic ratio of 0.6 (r = 0.6) exhibited the MoS2-2H crystalline structure whereas the P- containing samples prepared with Mo/(Mo + W) atomic ratio of 0.4 (r = 0.4(P)) exhibited the interplanar distance corresponding to (003) planes of MoS2-3R crystalline structure. Additionally, the best activity of the r = 0.4(P) sulfide catalyst was linked with the enhancement of the WS2 species surface exposure accompanied with a larger sulfidation degree of W species (from XPS). (C) 2016 Elsevier Ltd. All rights reserved.