RhCo双金属催化剂的研究Ⅵ.Rh_2Co_2/Al_2O_3上表面羰基氢化物及其动态行为  

STUDY OF Rh Co BIMETAL CATALYSTS Ⅵ. Surface Carbonyl Hydrides and Their Dynamic Behavior on Rh 2Co 2/Al 2O 3

作　　者：陈耀强[1] 龚茂初[1] 曹昭[1] 周建略 陈豫[1] 辛勤[2] 郭燮贤[2] 

机构地区：[1]四川大学化学系 [2]中国科学院大连化学物理研究所催化基础国家重点实验室

出　　处：《催化学报》1998年第1期9-13,共5页

基　　金：国家自然科学基金;中国科学院大连化学物理研究所催化基础国家重点实验室基金

摘　　要：利用连续流动微反研究了Ｒｈ２Ｃｏ２／Ａｌ２Ｏ３上的ＣＯ加氢反应．该反应在２００℃以上发生，反应活性随着温度的升高和Ｈ２／ＣＯ比的增大而增大．利用ＴＰＩＲ动态方法研究了Ｒｈ２Ｃｏ２／Ａｌ２Ｏ３上ＣＯ和Ｈ２的共吸附及其动态行为．结果表明，在Ｒｈ２Ｃｏ２／Ａｌ２Ｏ３的Ｒｈ上的孪生和桥式中心及Ｃｏ上的线式中心上，ＣＯ和Ｈ２室温共吸附时即有部分孪生、桥式ＣＯ及Ｃｏ上的线式ＣＯ转化为相应的羰基氢化物．随着温度的升高，剩余的孪生、桥式ＣＯ及Ｃｏ上的线式ＣＯ向羰基氢化物转化，而羰基氢化物又向多氢羰基氢化物转化．在ＣＯ加氢反应温度下，Ｒｈ２Ｃｏ２／Ａｌ２Ｏ３的三种吸附中心上只存在多氢羰基氢化物．与ＣＯ加氢反应和ＣＯ歧化的吸附态动态研究结果相关联，可以认为在Ｒｈ２Ｃｏ２／Ａｌ２Ｏ３上ＣＯ加氢生成ＣＨ４经由了羰基氢化物多氢羰基氢化物途径．CO hydrogenation on Rh 2Co 2/Al 2O 3 has been studied by using a flow micro reactor. CO hydrogenation took place over 220℃ and the activity increased with the reaction temperature and H 2/CO ratio. Coadsorption of CO and H 2 as well as dynamic behavior of coadsorbed CO and H 2 have been investigated by TP IR dynamic method. The results indicate that in coadsorption of CO and H 2 at 25℃, gem dicarbonyl CO, bridged CO and linear CO on Co transform partly into the corresponding carbonyl hydride. With increasing the temperature, the residual gem dicarbonyl CO, bridged CO and linear CO on Co transform also into the corresponding carbonyl hydride, while the carbonyl hydrides transform into the multi hydrogen carbonyl hydrides. At the reaction temperature, there are only the multi hydrogen carbonyl hydirdes which lead to the formation of CH 4 on Rh 2Co 2/Al 2O 3. On comparison of these results obtained in CO hydrogenation and in CO disproportionation, it is believed that in CO hydrogenation reaction, the scission of CO bond is via the carbonyl hydride multi hydrogen carbonyl hydride.

关 键 词：铑 钴 双金属催化剂 一氧化碳 加氢 羰基氢化物 

分 类 号：O643.36[理学—物理化学]