物理化学学报 >> 1999, Vol. 15 >> Issue (03): 234-240.doi: 10.3866/PKU.WHXB19990308

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K2O-Fe2O3系催化剂的穆斯堡尔谱研究

祝以湘, 陈荣钦, 封雷, 王军   

  1. 厦门大学化工系，物理化学研究所，固体表面物理化学国家重点实验室，厦门 361005|中国石油天然气集团公司，大庆石油化工总厂化工三厂，大庆 163714
  • 收稿日期:1998-06-09 修回日期:1998-09-22 发布日期:1999-03-15
  • 通讯作者:

Mossbuer Spectroscopic Studies of Fe2O3-K2O-Based Catalysts for Ethylbenzene Dehydrogenation

Zhu Yi-Xiang, Chen Rong-Qin, Feng Lei, Wang Jun   

  1. Department of Chemical Engineering Institute of Physical Chemistry State Key Laboratory for Physical Chemistry of the Solid Surfaces,Xiamen University,Xiamen 361005|The Thinl Chemical Factory,Daqing Petrochemical Complex,Daqing 163714
  • Received:1998-06-09 Revised:1998-09-22 Published:1999-03-15
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摘要：

利用穆斯堡尔谱在K2 O-Fe2 O3催化剂中检出了α-Fe2 O3(大晶粒及微晶 )、KFeO2、K1+ XFe11O17、α-FeOOH和γ-FeOOH等物相 ,它们的相对含量取决于催化剂的含钾量及煅烧温度, 相对含量的改变导致样品的穆斯堡尔谱图出现了复杂的变化 .与XRD相比 ,穆斯堡尔谱可对钾与氧化铁的相互作用进行更有效的表征 ,穆斯堡尔谱和TPR研究都表明钾可延缓催化剂中Fe(III)的被还原 .

关键词: 乙苯, 脱氢, 穆斯堡尔谱, 铁催化剂

Abstract:

Fe 2O 3 K 2O Catalysts with different content of K 2O and calcined at different temperature were characterized by using Mossbauer spectroscopy. It was found from the experiments that only a sextuplet assignable to Fe 3+ of α Fe 2O 3 could be detected while the K 2O content in these catalysts were lower than 5%and the calcination temperature was below 900℃;and complex spectra ,which could be fitted with several sextuplets of trivalent irons present in α Fe 2O 3, KFeO 2, K 1+ x Fe 11 O 17 and α FeOOH ,and a doublet of Fe 3+ in γ FeOOH ,would be observed if the K 2O content were 10%～27%and the calcination temperature were 800～900℃. The γ FeOOH, as a hydrous iron oxide ,was the decomposition product of KFeO 2 which was strong hydroscopic by absorbing moisture from the atmosphere. The results also suggested that Mossbauer spectroscopy was a better mean than XRD for the characterizations of Fe 2O 3-K 2O catalysts,by which ,α-FeOOH ,γ-FeOOH and α Fe 2O 3 in amorphous or crystallite forms ( unable to be found by XRD ) could be detected . It was also shown from the Mossbauer spectroscopy and a TPR studies that potassium could retard the reduction of Fe(III) to Fe(II) in the Fe 2O 3 K 2O catalysts. 

Key words: Ethylbenzene, Dehydrogenation, Mossbauer, Iron catalyst