引用本文:
席靖宇, 王志飞, 王卫平, 吕功煊. Cu-Ni/Zn催化剂甲醇裂解机理原位XPS研究[J]. 物理化学学报,
2002, 18(01): 82-86.
doi:
10.3866/PKU.WHXB20020119
Citation: Xi Jing-Yu, Wang Zhi-Fei, Wang Wei-Ping, Lü ng-Xuan. In-situ XPS Study for Reaction Mechanism of Methanol Decomposition over Cu-Ni/Zn Catalyst[J]. Acta Physico-Chimica Sinica, 2002, 18(01): 82-86. doi: 10.3866/PKU.WHXB20020119
Citation: Xi Jing-Yu, Wang Zhi-Fei, Wang Wei-Ping, Lü ng-Xuan. In-situ XPS Study for Reaction Mechanism of Methanol Decomposition over Cu-Ni/Zn Catalyst[J]. Acta Physico-Chimica Sinica, 2002, 18(01): 82-86. doi: 10.3866/PKU.WHXB20020119
Cu-Ni/Zn催化剂甲醇裂解机理原位XPS研究
摘要:
利用原位XPS 和TPDMS 技术研究了CuNi/Zn催化剂在甲醇裂解反应中的机理和活性中心.TPDMS脱附产物中仅检测到CH3OH、H2和CO,而未发现CH4和CH3OCH3、HCOOCH3等其它含氧物种,说明在CH3OH裂解过程中仅包括O－H、C－H键的断裂,而不存在C－O键的断裂过程.Insitu XPS的研究发现,在反应温度升高到200 ℃以上时,Cu/Zn催化剂中的Zn明显被还原,反映出Cu/Zn催化剂失活过程的CuZn合金生成过程,而在CuNi/Zn催化剂中未观察到Zn的还原,且表面出现Cu＋/Cu0共存的现象.Cu＋和Cu0很可能共同构成催化剂表面的活性中心,Cu＋应该是在甲醇裂解反应过程中形成的中间态.产物氢从CuNi/Zn 催化剂表面脱附为反应的控速步骤.
English
In-situ XPS Study for Reaction Mechanism of Methanol Decomposition over Cu-Ni/Zn Catalyst
Abstract:
Insitu XPS and TPDMS techniques were used to study the reaction mechanism and the active center of CuNi/Zn catalyst for methanol decomposition.Significant amount of CH3OH、H2 and CO were detected during the methanol decomposition with TPDMS,however no evidences of CH4、CH3OCH3 and HCOOCH3 formation were obtained.TPDMS results indicated that O－H and C－H bonds instead of C－O bond were broken in methanol decomposition on Cu/Zn/Ni catalyst.It was found that H2 desorption from the surface of CuNi/Zn catalyst was the rate control step.Insitu XPS studies confirmed that the Zn species was easily reduced when temperature was higher than 200 ℃ in Cu/Zn catalyst.However,similar reduction of Zn was not observed in Cu/Zn/Ni catalyst.Furthermore,both Cu＋ and Cu0 species were observed in Cu/Zn/Ni catalyst.Our study indicated that active center(s) in Cu/Zn/Ni catalyst may be Cu0 and/or Cu＋ species,in which Cu＋ formed during the reaction.
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