混合载体上钼催化剂甲烷化反应性能的研究  

THE METHANATION ACTIVITY OF SULFIDED Mo CATALYSTS SUPPORTED ON MIXED CARRIER

作　　者：黄志刚[1] 王学赋 伏义路[1] 

机构地区：[1]中国科学技术大学近代化学系

出　　处：《燃料化学学报》1990年第2期123-129,共7页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金委员会

摘　　要：以γ-Al_2O_3,ZrO_2及其混合物为载体,制备了五种硫化的钼催化剂(KW-01-KW-05),并对其常压及加压下的甲烷化反应性能进行了研究。观察到反应活性按KW-05至KW-01的顺序递减,反应的稳定性则以相反的顺序递减。在1.5MPa下的活性比常压下的活性增加2—8倍,而稳定性与常压下的类似。对比反应产物中CO_2生成量,可以认为,CO在钼催化剂上的甲烷化反应包括如下两个步骤:(1)3H_2+CO→CH_4+H_2O;(2)CO+H_2O→CO_2+H_2。用激光拉曼光谱研究了上述催化剂的表面结构与反应前后的变化。硫化前钼在催化剂上呈单层分布,无体相MoO_3和钼酸盐生成,并和差热分析的结果一致。硫化后的催化剂经常压反应后,催化剂表面发生MoS_2聚集现象,而加压反应后MoS_2特征峰减弱。在加压反应后的含锆样品上有积炭产生。Several sulfided molybdenum catalysts supported on γ-Al_2O_3, ZrO_2 and their mixtures——KW-01 (on γ-Al_2O_3), KW-02-KW-04 (on mixtures of γ-Al_2O_3 and ZrO_2)and KW-05 (on ZrO_2)——were prepared and their catalytic properties in the methanation of CO at atmospheric pressure and 1.5MPa were investigated.The reaction activities decreased in the following sequence: KW-05>KW-04>KW-03>KW-02>KW-01. The reaction stabilities decreased in the reverse order: KW-01>KW-02、KW-03>KW-04>KW-05. The activities at 1.5MPa increased 2-8 fold compared to those at atmospheric pressure,but there was no remarkable difference in reaction stabilities at 1.5MPa and 0.1MPa. Comparing the amounrs of CO_2 in reaction products,it is suggested that methanation of CO on molybdenum catalysts includes two steps:(1)CO+3H_2→CH_4+H_2,(2)CO+H_2O→CO_2+H_2.Surface structure and species of these catalysts were investigated before and after reaction using LRS. Before sulfidation there were no bulk MoO_3, Al_2(MoO_4)_3 or Zr(MoO_4)_2 in the samples——consistent with results of DTA.After sulfidation and reaction al atmospheric pressure MoS_2 aggregation on catalyst surface was observed. For reaction at higher pressures, the characteristic peak of MoS_2 weakened and carbon deposits were found on surface of zirconiuin containing samples.

关 键 词：混合载体 钼催化剂 甲烷化反应 

分 类 号：O643.36[理学—物理化学]