化学学报 ›› 1997, Vol. 55 ›› Issue (7): 632-637. 上一篇    下一篇

研究论文

RhCo双金属催化剂的研究III. Rh+Co/Al2O3上表面羰基氢化物及其动态行为

陈耀强;龚茂初;曹昭;周建略;陈豫;辛勤;张慧;郭燮贤   

  1. 四川大学化学系;中国科学院大连化学物理研究所
  • 发布日期:1997-07-15

Study of RhCo bimetallic catalysts III. Surface carbonyl hydride and their dynamic behavior on Rh+Co/Al2O3

CHEN YAOQIANG;GONG MAOCHU;CAO ZHAO;ZHOU JIANLUE;CHEN YU;XIN QIN;ZHANG HUI;GUO XIEXIAN   

  • Published:1997-07-15

利用连续流动微反研究了Rh+Co/Al2O3催化剂的CO加氢反应, 结果表明反应在220℃以上发生, 反应活性随着温度的升高和H2/CO值的增加而增加。利用TP-IR动态方法研究了Rh+Co/Al2O3上CO和H2共吸附及其动态行为。结果表明在Rh+Co/Al2O3的孪生及线式中心上, CO和H2室温共吸附时即有部分孪生及线式CO转化为相应的羰基氢化物, 随着温度的升高, 剩余的孪生和线式CO继续向相应的羰基氢化物转化。而羰基氢化物则向多羰基氢化物转化。在到达反应温度之前, 催化剂表面只存在羰基氢化物及相应的多氢羰基氢化物。在反应温度则导致产物CH4生成。与CO加氢反应和CO歧化的吸附态研究结果相关联, 作者认为Rh+Co/Al2O3上CO加氢生成CH4是经由羰基氢化物-多氢羰基氢化物途径。

关键词: 钴, 催化剂, 氧化铝, 一氧化碳, 吸附, 铑, 加氢反应

CO hydrogenation of Rh+Co/Al2O3 has been studied by using a flow micro-reactor. CO hydrogenation took place over 220℃ and reaction activity increased with the reaction temperature and H2/CO ratio. Coadsorption of CO and H2 as well as dynamic behavior of coadsorbed CO and H2 have been investigated by TP-IR dynamic method. The results indicate that in coadsorption of CO and H2 at 20℃, gem-dicarbonyl CO and linear CO transformed partly into the corresponding carbonyl hydride. With increasing the temperature, the residual gem-dicarbonyl CO and linear CO transformed also into the corresponding carbonyl hydride, while the carbonyl hydrides transformed into the multi-hydrogen carbonyl hydirdes. Before arriving at the reaction temperature, there are only the carbonyl hydrides and the multi-hydrogen carbonyl hydride which led to the formation of CH4 at the reaction temperature on the surface of Rh+Co/Al2O3. To relate these results with the results obtained in CO hydrogenation and in CO disproportionation. We believe that in CO hydrogenation reaction, the scission of C-O bond is via the carbonyl hydride-multihydrogen carbonyl hydride.

Key words: COBALT, CATALYST, ALUMINIUM OXIDE, CARBON MONOXIDE, ADSORPTION, RHODIUM, HYDROGENATION

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