纳米β-Mo_2C催化剂的制备及K改性对合成低碳醇反应性能的影响  

Preparation of nano-sized β-Mo_2C catalysts and influence of K modification on their catalytic performance for CO hydrogenation to higher alcohol

作　　者：赵立红 闫捷 房克功[2] 魏灵朝 蒋元力 孙予罕[2,3] 

机构地区：[1]河南能源化工集团研究院有限公司,河南郑州450046 [2]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 [3]中国科学院上海高等研究院,上海201203

出　　处：《工业催化》2014年第7期515-520,共6页Industrial Catalysis

基　　金：国家自然科学基金重大项目(20590363)

摘　　要：以柠檬酸为络合剂,采用溶胶-凝胶法及程序升温碳化法制备了纳米β-Mo2C催化剂,适宜的碳化温度为（650 ～700）℃.考察了K含量对K/β-Mo2C催化剂织构及CO加氢反应性能的影响,结果表明,适量K助剂的加入能提高催化剂的比表面积和合成醇选择性,过量K助剂与Mo6＋物种形成了惰性的钼酸盐（K2MoO4和/或K2 Mo2 O7）,该钼酸盐可能覆盖了CO加氢反应的活性中心,降低了β-Mo2C催化剂的CO加氢反应活性;K含量对总醇收率和C2 ＋OH选择性的影响呈火山型变化规律,K与Mo物质的量比最佳为0.2～0.4.Using citric acid as the complexing agent,a series of nano-sized β-Mo2C catalysts was prepared by a modified sol-gel method followed by a temperature-programmed carbonization process under argon atmosphere,and the proper carbonization temperature was （650-700） ℃.The influence of K contents on the texture properties of K/β-Mo2C catalysts and their catalytic performance for CO hydrogenation were investigated.The results showed that the addition of proper amounts of K improved the surface area of β-Mo2 C catalysts and the selectivity of alcohol synthesis.However,as K content further increased,inert K2MoO4 and/or K2Mo2O7 formed on the surface of the catalysts and part of the active sites of the catalyst for CO hydrogenation were covered,which resulted in the decrease of the catalytic activity of β-Mo2C catalyst.The trend of the influence of K contents on total yield of alcohol and the selectivity to C2 ＋OH was ‘ volcano plot’.The optimal molar ratio of K to Mo was 0.2-0.4.

关 键 词：催化剂工程 溶胶-凝胶法 柠檬酸 纳米β-Mo2C催化剂 CO加氢反应 

分 类 号：TQ426.6[化学工程] O643.36[理学—物理化学]