采用Co(Ac)2、(NH4)6Mo7O24.4 H2O和乙二胺的浓氨水溶液共浸渍γ-Al2O3载体,制备适合于含硫原料油硫化活化的炭改性Co-Mo催化剂。炭改性Co-Mo催化剂用噻吩模拟原料油硫化后脱硫活性与对照Co-Mo催化剂用DMDS硫化的脱硫活性相当。由于添加物乙二胺和Co^2+形成络合物,推迟了Co^2+的硫化,使活性金属Mo在Co之前完成硫化,这有利于助剂Co^2+迁移到已形成的MoS2活性相的侧边形成Co-Mo-S活性结构。在硫化过程中,醋酸和乙二胺的碳化,减弱了载体与活性金属的相互作用,使活性金属Mo更容易硫化。醋酸和乙二胺的共同作用,促成了对催化剂的碳改性,改善了催化剂噻吩模拟油硫化的效果。
Carbon modified Co-Mo catalyst was prepared through the impregnation of γ-Al2O3 with aqueous NH3 solution of cobalt acetate, (NH4)6Mo7O24·4H2O and ethylenediamine (En), which can be activated through sulfidation with oil feed. The resulted catalyst sulfided by the thiophene containing model oil feed exhibited equivalent HDS activities to Co Mo catalyst presulfided with DMDS. Ethylenediamine coordinates with Co^2+ ions postponed the sulfidation of Co^2+ ions. As a result, the sulfidation of Mo took precedence over that of Co. This was favorable for Co promoters, moving to the edge of MoS2 slabs to form Co-Mo-S active structures. During the sulfidation, the carbonization of acetate and En weakened the interaction between the active metals and support, which was beneficial to the sulfidation of active metals. The mutual effects of acetate and En were brought on the carbon modified Co-Mo catalyst and evidently promoted its sulfidation with thiophene model feed.