负载型NiO-MoO_3/SiO_2-Al_2O_3-TiO_2超细镍金属催化剂加氢性能的研究

用原位溶胶-凝胶法制备了不同SiO2含量及不同总金属含量的高性能负载型NiO-MoO3/SiO2-Al2O3-TiO2超细镍金属加氢催化剂。根据XRD、TPR及TPD结果,催化剂表面产生了还原性能不同的多种镍原子活性位,金属镍与载体间的相互作用较强,并在其表面呈超细分散状态,为中等强度的酸性催化剂。采用不同的不饱和烃原料,考察催化剂的加氢性能,结果表明,载体酸性对不同的不饱和烃原料感受性不同,原料苯及催化裂化柴油加氢需要载体提供的有效酸量要大于航空煤油及双环戊二烯加氢;此外,适当地增加金属NiO的含量,调节Ni、Mo比,能够有效地增大活性组分镍的分散度,能量状态较高的镍原子数增多,从而有利于提高该催化剂对不饱和烃原料的加氢性能,延长使用寿命。

Hydrogenation performance of supported NiO-MoO/SiO2-Al2O3-TiO2 ultrafine nickel catalysts

The high-performance supported NiO-MoO3/SiO2-Al2O3-TiO2 ultrafine nickel catalysts with different SiO2 and total metal contents for hydrogenation were prepared by in-situ sol-gel method.The results of XRD,TPR and TPD showed that all kinds of ultrafine nickel particles dispersed on the support were reduced to various extents,which interacted with support strongly.The acidity of the catalyst was moderate.Different unsaturated hydrocarbon feeds were used to study the activity and stability of the catalysts.It was found that different feedstocks had different requirements for the acidity of the support.The hydrogenation of benzene and FCC light cycle oil required more effective acids than jet fuel and dicyclopentadiene.In addition,the dispersion and active sites of nickel atoms could be effectively enhanced by increasing NiO contents and adjusting the ratio of Ni to Mo,which thus improved the activity and life of the catalysts for hydrogenation of the unsaturated hydrocarbons.