Ag助剂对Ni/TiO_2-Al_2O_3催化剂催化环戊二烯选择加氢性能反应的影响  

EFFECT OF SILVER PROMOTER ON THE PERFORMANCE OF Ni/TiO_2-Al_2O_3 CATALYST IN SELECTIVE HYDROGENATION OF CYCLOPENTADIENE

作　　者：熊凯 Xiong Kai(Yanshan Branch of SINOPEC Beijing Research Institute of Chemical Industry,Beijing 102500,China)

机构地区：[1]中国石化北京北化院燕山分院,北京102500

出　　处：《精细石油化工》2018年第4期30-34,共5页Speciality Petrochemicals

基　　金：中国石油化工股份有限公司资助项目(416016)

摘　　要：以TiO_2-Al_2O_3复合氧化物为载体,Ni为主活性组分,依次考察了Ni的负载量、助剂金属(Co、Cu、Zn、La和Ag)的种类和含量对催化剂催化环戊二烯选择加氢反应的影响。实验结果表明,5种助剂中,Ag可以最大程度地提升Ni/TiO_2-Al_2O_3催化剂的选择加氢活性和提高环戊二烯的转化率及环戊烯的选择性。催化剂的Ni负载量为15%,Ag助剂的加入量为3.0%时,在反应温度45℃、反应压力0.5 MPa、氢/烃(摩尔比)1.2、液体体积空速8.0h^(-1)的条件下,环戊二烯的转化率大于92.5%,环戊烯的选择性大于91.5%。催化剂在200h稳定性考察实验中,呈现较好的稳定性。BET测试结果表明,Ag-Ni/TiO_2-Al_2O_3催化剂的比表面积为142.7m^2/g,孔体积为0.41mL/g,孔集中分布在4~9nm之间,最可几孔径为7.1nm;XRD测试结果表明,Ag助剂的加入使NiO的晶粒变小并在载体表面分散的更均匀,而使TiO_2的晶粒变大并在载体表面聚集,减弱了NiO与载体中TiO_2的相互作用;TPR测试结果表明,Ag助剂的加入使催化剂的氢还原峰向低温方向移动了80℃以上,使催化剂更容易还原活化。Catalysts were synthesized using TiO2-Al2O3 composite as the support,nickel as the active metal,cobalt,copper,zinc,lanthanum or silver as the promoter,for which the contents of nickel,types as well as the contents of promoters were investigated to determine the effects on the selective hydrogenation of cyclopentadiene.Experimental results showed that silver was the best promoter in the 5 types of promoters been studied,and it could greatly enhance the conversion of cyclopentadiene and selectivity of cyclopentene for the Ni/TiO2-Al2O3 catalyst.For Ag-Ni/TiO2-Al2O3 catalyst of 15 wt%of nickel and 3.0%of silver,the conversion of cyclopentadiene was 93.1% and the selectivity of cyclopentene was 91.5% under evaluation conditions as reaction temperature of 45℃,reaction pressure of 0.5 MPa,molar ratio between hydrogen and cyclopentadiene of 1.2 and liquid hourly space velocity of 8.0 h（-1）.BET measurements of the Ag-Ni/TiO2-Al2O3 catalyst showed that the specific surface area was 142.7 m2/g,pore volume was 0.41 mL/g,the most probable pore diameter was 7.1 nm,pore diameters were concentrated in the range of 4 to 9 nm.XRD characterization of the Ag-Ni/TiO2-Al2O3 catalyst indicated that the silver promoter could decrease the grain size of NiO and improve its distribution on the surface of the catalyst,while increase the grain size of TiO2 and enhance its aggregation on the surface of the catalyst and weaken the interactions between NiO and TiO2.TPR measurements revealed that the silver promoter aroused near 80℃temperature shift of maximum hydrogen exhausting peak and made Ni/TiO2-Al2O3 catalyst more easily reduced by hydrogen compared with Ag-Ni/TiO2-Al2O3 catalyst.

关 键 词：环戊二烯 镍催化剂 选择加氢 银助剂 铝钛载体 

分 类 号：TQ231.22[化学工程—有机化工]