FCC汽油选择性加氢硫转移催化剂的研究

 制备了以γ-Al₂O₃为载体的Ni基选择性加氢硫转移催化剂Mo-Ni/γ-Al₂O₃，并用于催化裂化汽油的加氢硫转移反应。对比了预硫化型和氧化型Mo-Ni/γ-Al₂O₃催化剂的活性和选择性，并考察了无氧焙烧温度、活性组分负载量对预硫化型Mo-Ni/γ-Al₂O₃催化剂加氢硫转移催化性能的影响。采用模型化合物研究了硫醇在Mo-Ni/γ-Al₂O₃催化下的反应，考察了烯烃和硫醇对硫转移反应的影响。结果表明，无氧焙烧温度400℃下制备得到的w(NiO)=8.2%、w(MoS₂)=5.6%的预硫化型Mo-Ni/γ-Al₂O₃催化剂具有相对较高的加氢硫转移反应催化活性和选择性；硫醇与烯烃的反应在催化剂表面的加氢活性位上进行，硫醇先加氢脱硫，生成吸附态H₂S，吸附态H₂S再与吸附的烯烃反应生成大分子硫醇或硫醚，达到硫转移的目的。

Study on the Selective Hydrogenation Catalyst for Sulfur Transfer in FCC Gasoline

The bimetal Ni-based selective hydrogenation catalysts for sulfur transfer supported on γ-Al₂O₃were prepared, and used to the selective hydrogenation of FCC gasoline. The catalytic activity and selectivity of the presulfided Mo-Ni/γ-Al₂O₃catalyst were compared with oxidation Mo-Ni/γ-Al₂O₃catalyst. The effects of calcination temperature, contents of Ni and Mo on the sulfur transfer performance of the presulfided Mo-Ni/γ-Al₂O₃catalyst were investigated. Furthermore, the influences of olefin and mercaptan for sulfur transfer were studied by the reaction of model mercaptan and olefin over Mo-Ni/γ-Al₂O₃catalyst. Experimental results showed that when optimum preparation conditions were selected (the anaerobic calcination temperature was 400℃, the mass fraction of NiO was 8.2% and MoS₂ was 5.6%), the catalytic activity and selectivity of the presulfided Mo-Ni/γ-Al₂O₃catalyst were relatively superior in the selective hydrogenation of FCC gasoline for sulfur transfer. The reaction of thiol and olefin happened on the active sites of hydrogenation on the surface of Mo-Ni/γ-Al₂O₃ catalyst. Hydrodesulfurization of thiol firstly produced adsorbed H₂S, which then reacted with adsorbed olefin and formed macromolecular thiol or thioether.