β-Mo_2C和Ni_3Mo_3N/β-Mo_2C的制备及其甲烷化反应性能研究  

Preparation of β-Mo_2C,Ni_3Mo_3N/β-Mo_2C and its catalytic performance for methanation

作　　者：霍晓东[1,2] 王志青[1] 张戎[1,2] 宋双双[1] 黄戒介[1] 房倚天[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报》2016年第4期457-462,共6页Journal of Fuel Chemistry and Technology

基　　金：中国科学院战略性先导科技专项(XDA07050100);中国科学院青年创新促进会项目(2014156);中国科学院国家外国专家局创新团队国际合作伙伴计划资助;山西省青年科技研究基金(2013021007-2)~~

摘　　要：通过焙烧钼酸铵和六次甲基四胺(HMT)生成的络合物,制备β-Mo_2C。在此基础上加入Ni助剂制备了Ni_3Mo_3N/β-Mo_2C双金属碳化物催化剂。采用XRD、SEM、HRTEM、低温氮吸附、元素分析等方法对催化剂进行了表征,考察了其合成气甲烷化反应性能。结果表明,β-Mo_2C有较高的CO转化率,但CO转化率和CH_4选择性分别从第10h的75.93%和36.79%降低到了第100h的67.41%和33.54%。因此,β-Mo_2C活性不够稳定且CH_4选择性较低。而Ni助剂的加入显著提高了催化剂的甲烷化活性及稳定性,使CO转化率和CH_4选择性分别从第10h的83.15%和46.64%升高到了第100h的92.51%和57.23%。这是因为Ni助剂的加入有助于生成Ni_3Mo_3N,新生成的Ni_3Mo_3N有利于甲烷化反应。A complexes was produced using hexamethylenetetramine（ HMT） as the complexing agent of ammonium molybdate,and β-Mo_2C was prepared by a simple thermal decomposition of this complexes. And then Ni was introduced and the bimetallic carbide Ni_3Mo_3N / β-Mo_2C was prepared. The as-prepared products were characterized by XRD,low-temperature nitrogen adsorption,SEM,HRTEM,element analysis（ EA）,and the performances of the prepared catalysts for methanation were investigated. The results showed that the bulk molybdenum carbide exhibited high conversion of CO（ x_（CO））,but x_（CO）and selectivity of CH_4（ sCH4） on β-Mo_2C decreased from 75.93% and 36. 79% to 67. 41% and 33. 54% within 100 h. Thus the catalytic activity was not stable and sCH_4 was low. The addition of Ni markedly promoted the catalyst activity and stability,x_（CO）and sCH_4 on Ni_3Mo_3N / β-Mo_2C increased from 83.15% and 46. 64% to 92. 51% and 57. 23% within 100 h,which should be attributed to the newly produced Ni_3Mo_3N after Ni addition.

关 键 词：碳化钼 氮化镍钼 甲烷化 

分 类 号：O643[理学—物理化学]