2005 Volume 48 Issue 6 Pages 344-350
The present study investigated the effects of trans-1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid (CyDTA) addition on the 1-octene hydrogenation activity and surface structure of CoMo/Al2O3 catalyst as a method to control the olefin hydrogenation activity. Irrespective of Co/Mo molar ratio, 1-octene hydrogenation activity at 453 K and 1.3 MPa decreased in the following order: Mo/Al2O3 > CoMo/Al2O3 > CyDTA-CoMo/Al2O3 Co/Al2O3. Modification with CyDTA had little effect on the hydrogenation activity of Mo/Al2O3. Thus, modification with CyDTA facilitates the inhibiting effect of Co addition on the hydrogenation of 1-octene. Our previous study found that modification with CyDTA greatly improves the hydrodesulfurization (HDS) activity of CoMo/Al2O3. Therefore, we expect that modification with CyDTA will greatly improves the HDS selectivity of CoMo/Al2O3 in the presence of olefins. Furthermore, the present characterization of CoMo/Al2O3 modified with CyDTA by NO adsorption techniques suggested that modification of CoMo/Al2O3 with CyDTA facilitates the formation of the Co-Mo-S phase even at lower Co/Mo molar ratio, at which Co atoms block the edge sites of MoS2 nanoclusters, leading to the improved HDS selectivity.