超高比表面炭载钼煤气甲烷化催化剂  

METHANATION OF SYNGAS OVER MOLYBDENUM CATALYSTS SUPPORTED ON ACTIVATED CARBON WITH ULTRA-HIGH SURFACE AREA

作　　者：杨骏[1] 黄止而[1] 王定珠[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

出　　处：《燃料化学学报》1994年第3期264-268,共5页Journal of Fuel Chemistry and Technology

摘　　要：以沥青中间相为原料，氢氧化钾直接活化，获得了比表面达２３６３ｍ￣２／ｇ的超高比表面炭分子筛（ＣＭＳ）。分别以ＣＭＳ、ＳｉＯ＿２、活性炭和θ－Ａｌ＿２Ｏ＿３为担体，制备了负载钼催化剂，并研究其加压甲烷化反应性能，发现活性依下面顺序增加：θ－Ａｌ＿２Ｏ＿３＜ＳｉＯ＿２＜活性炭（ＡＣ）＜ＣＭＳ。还分别以钼酸铵和磷钼酸（ＨＰＭｏ）为前驱体，制备了ＣＭＳ负载钼催化剂，并考察了其煤气甲烷化活性，发现不同的催化剂前驱体对催化剂反应活性影响很大。根据产物中ＣＨ＿４／ＣＯ＿２的变化，推测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。A unique carbon molecular sieve(CMS)having an ultra-high surface areahigher than 2300m￣2/g was developed. The carbon material was made by a direct chemical ac-tivation process in which mesophase pitch was reacted with excess KOH. Several molydenumcatalysts supporded on θ-Al_2O_3、 SiO_2,activated carbon and CMS were prepared and theircatalytic performances in the methanation of CO were examined.The catalytic activities in-creased in the following sequence:θ-Al_2O_3<SiO_2<activated carbon<CMS. Two catalystswith HPMo and(NH_4)_6Mo_7O_(24)·2H_2O as precursors were prepared and tested for their usein the methanation of CO. The results show that the activity of HPMo/CMS for CO metha-nation was much higher than that of MoO_3/CMS.Comparing the ratios of CH_4/CO_2 in reac-tion products,it is suggested that the methanation of CO on molybdenum catalysts proceedsthrough two steps:(1)CO+3H_2→CH_4+H_2O;(2)CO+H_2O→CO_2+H_2

关 键 词：炭分子筛 钼催化剂 煤气 甲烷化 

分 类 号：TQ544[化学工程—煤化学工程]