The catalyst precursors of B-Ni2P/SBA-15 were synthesized by co-impregnation using (NH4)2HPO4 as the source of phosphorus, Ni(NO)3 as the source of nickel and H3BO3 as the source of boron. The B-Ni2P/SBA-15 catalysts with an initial P/Ni molar ratio of 0.8 and a boron content from 0.35％ to 2.10％(w) were prepared by temperature-programmed reduction in a H2 flow. The structure of the catalysts was characterized by X-ray diffraction (XRD), N2 adsorption-desorption, transmission electron microscopy (TEM) and NH3 temperature-programmed desorption (NH3-TPD). The catalytic performances of hydrodesulfurization (HDS) were evaluated in a fixed-bed microreactor using dibenzothiophene (DBT) as a model compound. The results showed that the B-Ni2P/SBA-15 catalysts still retained mesoporous structure. The Ni2P phase was mainly active phases in all the catalysts. The proper addition of boron reduced the Ni2P active phases but increased the specific surface area of the catalysts. The amount of acid in B-Ni2P/SBA-15 also increased with addition of boron. When the reaction temperature was increased from 300 to 360 ℃, the HDS conversion of DBT over the catalyst clearly improved with an increase in the content of boron. The B-Ni2P/SBA-15 catalyst with a boron content of 1.40％(w) had the best catalytic activity. The mechanism of the HDS of DBT consisted of main direct desulfurization (DDS) over the B-Ni2P/SBA-15 catalysts.%以介孔分子筛SBA-15为载体,磷酸氧二铵为磷源,硝酸镍为镍源,硼酸为硼源,采用共浸渍法制备了B-Ni2P/SBA-15催化剂前驱体,然后采用程序升温氢气还原法,制备了nP/nN1=0.8,B含量为0.35%-2.10%(W)的一系列B-Ni2P/SBA-15催化剂.用X射线衍射(XRD)、N2吸附脱附、透射电子显微镜(TEM)和氨气程序升温脱附(NH3-TPD)等表征技术对催化剂的结构进行了研究,以1%(W)二苯并噻吩(DBTy十氢萘溶液为模型化合物,在微型固定床反应器上对催化剂的加氧脱硫(HDS)性能进行了评价.结果表明,B-Ni2P/SBA-15催化剂仍具有介孔结构,Ni2P为主要的活性物相.适量B助剂的加入可促使Ni2P晶粒减小,催化剂比表面积增加.此外,随着B含量的增加,B-Ni2P/SBA-15催化剂的总酸量也增加.当反应压力为3.0 MPa,反应温度由300℃升高至360℃时,B含量对Ni2P/SBA-15催化剂活性有明显的影响,B含量为1.40%(W)的B-Ni2P/SBA-15催化剂加氢脱硫活性最高.B-Ni2P/SBA-15催化剂上二苯并噻吩的加氢脱硫的反应机理以直接脱硫为主.
展开▼
