Mo在NiO/Al_2O_3-TiO_2催化剂中助催化作用的研究  

Study of Promotion of Mo to NiO/Al_O_3-TiO_2 Catalysts

作　　者：林西平[1] 邬国英[1] 周永生[1] 冯艳果[1] 

机构地区：[1]江苏工业学院,江苏省精细石油化工重点实验室,江苏,常州,213016

出　　处：《江苏工业学院学报》2005年第4期1-5,共5页Journal of Jiangsu Polytechnic University

基　　金：中国石油化工集团总公司资助项目(X599021;103105);江苏省高技术研究计划项目(BG 2002011)

摘　　要：采用引入钼组分的办法,调变NiO-TiO2-Al2O3体系的性能。TPR结果发现,含Mo催化剂产生了还原性能不同的多 种镍原子位。当n(Ni):n(Mo)=3．04时,形成了3个还原峰:峰Ⅰ为362．5℃,与纯NiO的最高还原峰接近;峰Ⅱ位于 482．1-491．6℃之间,与NiO-TiO2-Al2O3催化剂tm为483．4℃接近,峰形都比较宽;在430．2℃还存在1个还原态(峰 Ⅲ),说明骨架内作用的复杂性。可以推测,催化剂中加入Mo后,减弱了Ni与载体之间的相互作用力,生成了容易被还原的, 类似于纯NiO样品的Ni原子位。同时,Mo的引入增加了NiO-TiO2-Al2O3催化剂的氢化学吸附量。在Mo含量较低时,即 当n(Ni):n(Mo)=5．22和9．47时,表面镍原子浓度不高,耗氢量也低于粉状纯NiO催化剂的。随着Mo含量的增加,当 n(Ni):n(Mo)=3．69和3．04时,表面镍原子浓度高,单位质量金属镍的耗氢量远高于其它样品。证明Mo的突出作用是 提高了催化剂中活性组分镍的分散度。高钼的NiO-MoO3-TiO2-Al2O3型催化剂的选择性加氢脱芳烃精制煤油的芳烃含量 平均低于200 μg/g,所用的反应条件是,反应温度180℃,压力1．2 MPa,LHSV2．0 h-1,氢油体积比500: 1。表明n(Ni) :n(Mo)=3．04-5．22的NiO-MoO3-TiO3-Al2O3型催化剂的加氢脱芳烃性能满足煤油脱芳烃和除味的要求。Temperature programmed reduction （TPR） technique was used for studying superfine nickel hydrogenation catalyst NiO-TiO2-Al2O3 with surface modifying of Mo promoter in this system. It was observed that several active sites of nickel component on the surface were formed because of incorporating of Mo into the network of the muhieonponent NiO-TiO2-Al2O3. When the Mo content was high, for n （Ni） ： n （Mo） =3.04, there existed three hydrogen-uptake peaks： the peak of tm=362. 5℃ （Ⅰ） was near to the ones of NiO powder, the broader peak of tm =482. 1-491.6℃ （ Ⅱ ） was the same with ones of tm=483.4℃ of NiO-TiO2-Al2O3 catalyst, the third peak t,=430. 2℃ （Ⅲ）. NiO-TiO2-Al2O3 catalyst with Mo promoter had higher hydrogen-uptake ability. The hydrogen consume amount in TPR determent increased with Mo content in the catalyst system. For KC-58 with n （Ni） ： n （Mo） =3.04 it possessed the highest chemical adsorption ability among the experiment samples including NiO powder, in which all of Ni atoms were not exposed to become surface atoms. It was assumed that Mo played an important role in increasing dispersion of active nickel on the surface. In the hydrodearomaties of jet fuel from Nanjing Refinery NiO-MoO3-TiO2-Al2O3 catalysts with a given amout of Mo promoter （n （Ni）：n （Mo） =3.04-5.22） had fine performance, activity and stability. Aromatics contents in produced oils were lower than 200μg/g under the reaction conditions of 180℃2, 1.2 MPa, LHSV2. 0 h^-1, V （H2） ：V （Oil） =500：1. The mechanism of Mo promotion in superfine NiO-TiO2-Al2O3 needs to be studied.

关 键 词：NiO/Al2O3-TiO2 程序升温还原(TPR) 钼助催化剂 加氢脱芳烃催化剂 

分 类 号：O643.36[理学—物理化学] TQ426.8[理学—化学]