物理化学学报 >> 1998, Vol. 14 >> Issue (06): 527-533.doi: 10.3866/PKU.WHXB19980609

研究论文 上一篇    下一篇

La-Ce-Cu系列催化剂SO2中毒机理研究

嵇世山, 翁端, 谭瑞琴, 张志强, 曹立礼   

  1. 清华大学化学系，材料科学与工程系，北京 100084
  • 收稿日期:1997-09-18 修回日期:1998-01-18 发布日期:1998-06-15
  • 通讯作者: 嵇世山

Studies of SO2 Poisoning Mechanism on La-Ce-Cu Catalysts

Ji Shi-Shan, Weng Duan, Tan Rui-Qin, Zhang Zhi-Qiang, Cao Li-Li   

  1. Department of Chemistry,Department of Materiel Science Engineering,Tsinghua University,Beijing 100084
  • Received:1997-09-18 Revised:1998-01-18 Published:1998-06-15
  • Contact: Ji Shi-Shan

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摘要：

采用NH4NO3共熔法合成La－Ce－Cu系列样品，并通过XRD分析了样品的相组成. XRF证明了系列样品组成均为氧缺陷型化合物．用TEM研究了样品的表面结构，发现随着SO2中毒的加深，Cu向表面偏析与S结合生成新的化合物，导致了原晶体结构的变形，同时证明纯CeO2不发生S中毒． XPS研究表明：样品La.029Ce0.57Cu0.14Ox中毒后Cu从La2CuO4中分解出来并与S结合生成CuSO4；相应的CeO2参与了中毒反应，生成Ce2O3,整个中毒反应如下：
La2CuO4＋2CeO2＋SO2＝CuSO4＋La2O3＋Ce2O3.

关键词: La-Ce-Cu催化剂, SO2中毒, 结构表征

Abstract:

Samples of La-Ce-Cu series were prepared with ammonium nitrate (NH_4NO_3) comelted method and the compositions of the samples were analyzed by XRD, XRF results showed that all the samples were O-defect compounds. The superficial structure were characterized by TEM. It was found that Cu segregates towards the surface and forms a new compound with S with the deepening of SO2 poisoning which causes the distortion of the original crystal structure. It, also showed that pure CeO2 will not be poisoned by sulphur. XPS analysis showed that after poisoning reaction Cu seperates from La2CuO4 and combines with S to form CuSO4. Correspondingly CeO2 participates in the poisoning reaction and forms Ce2O3, i.e.La2CuO4 + 2CeO2 + SO2 = CuSO4 + La2O3 + Ce2O3.

Key words: La-Ce-Cu catalysts, SO2 poisoning, Structure characterization