CH_4三自热重整制合成气催化剂的制备与性能  

Preparation and Performance of Catalysts for Tri-reforming of CH_4-CO_2 to Synthesis Gas

作　　者：薛茹君[1] 王庆超[1] 

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232001

出　　处：《安徽理工大学学报（自然科学版）》2013年第2期12-16,共5页Journal of Anhui University of Science and Technology:Natural Science

摘　　要：以稀土氧化物(CeO2、La2O3)为助剂对Ni/类水滑石催化剂进行改性,用于CH4三自热重整反应,旨在改善催化剂的活性和稳定性。以共沉淀法先制得铈(镧)掺杂的镁铝类水滑石(LDHs),焙烧后再以浸渍法负载镍活性组分得到Ni/LDHs前驱体,再焙烧得到NiO/CeO2(La2O3)-MgO-Al2O3催化剂。用ICP-AES进行Ni、Mg、Al元素分析,BET法测试催化剂比表面积,XRD表征催化剂物相,H2-TPR表征催化剂活性中心。考察了原料气组成为n(CH4)∶n(CO2)∶n(H2O)∶n(O2)=1∶0.5∶1.8∶0.1时催化剂在750℃、0.1MPa条件下CH4三自热催化重整的稳定性及积炭性能。结果表明,制得的Ni/CeO2(La2O3)-MgO-Al2O3催化剂中,Ni组分以NiO形式存在于催化剂表面,能降低催化剂还原活化温度;在催化剂中掺杂CeO2(La2O3)对其活性有一定程度的调控作用,且能够很好地改善催化剂的抗积碳性能;当Ni的质量分数为10%、Al与Mg的质量比为1.7时,催化活性较好,750℃、0.1 MPa时,CH4转化率达到92.3%,CO2转化率达到98.3%;反应100 h后,Ni/CeO2(La2O3)-MgO-Al2O3催化剂上的CH4转化率仍可维持在75%以上。In order to improve activity and stability of catalyst being used in reaction of methane tri - reforming , Ni/LDHs was modified with rare earth （CeO2, La2O3）. Ce （La） -doped Mg- A1 layered double oxide support （LDO） was obtained through calcination at 500℃ from the corresponding Ce （La） - doped Mg - A1 layered double hydroxides （LDHs） , which was prepared by co - precipitation method. Then the active component nickel was loaded on Ce （La） -LDO by impregnation to reconstruct the Ni/LDHs precursor. After roasting, the NiO/ Ce （La） -MgO -A1203 catalyst was prepared from the precursor at last. The Ni, Mg, A1 elements in the cata- lyst was analyzed via ICP - AES. The specific surface area of the catalyst was tested by the BET method. The phase of the catalyst was characterized by XRD. The active center of the catalyst was characterized via H2 - TPR techniques. The catalytic performance of the catalysts for tri - reforming of CH4 - CO2 to Synthesis Gas were test- ed with the feed gas which composition wash （CH4）：n （CO2）：n （H20）：n （O2） = 1：0.5：1.8：0.1 under 750 ℃ and 0.1 MPa. The results show that the NiO component was distributed on the surface of NiO/Ce （La） - MgO - Al2O3 catalyst, and the reduction temperature of NiO was decreased largely. The doping component CeO2 （ or La203 ） within the catalyst could adjust catalytic activity in a certain extent, and could improve the resistance performance to coke deposit greatly. The catalytic activity is better when the mass fraction of Ni isl0%, the mass ratio of A1, and Mg is 1.7. Under the condition of 750 ℃ and 0.1 MPa, the CH4 conversion rate is 92.3%, and CO2 conversion rate is 98.3%. After having reacted 100 h, the CH4 conversion rate of Ni/CeO2 （ La203 ） - MgO -A1203 catalyst still remains above 75%.

关 键 词：Ni CeO2(La2O3)-MgO-Al2O3催化剂 制备 CH4-重整 合成气 

分 类 号：O643[理学—物理化学] TQ426[理学—化学]