物理化学学报 >> 1994, Vol. 10 >> Issue (11): 971-977.doi: 10.3866/PKU.WHXB19941103

研究论文 上一篇    下一篇

NaCl和B2O3在修饰FeOχ催化剂中的协同作用

熊国兴, 夏新瑞, 陈恒荣, 郭燮贤   

  1. 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,大连 116023
  • 收稿日期:1993-08-30 修回日期:1994-02-28 发布日期:1994-11-15
  • 通讯作者: 熊国兴

Synergetic Effect between NaCl and B2O3 in Modified FeOχ Catalysts

Xiong Guo-Xing, Xia Xin-Rui, Chen Heng-Rong, Guo Xie-Xian   

  1. State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Science,Dalian 116023
  • Received:1993-08-30 Revised:1994-02-28 Published:1994-11-15
  • Contact: Xiong Guo-Xing

摘要:

应用连续催化反应,XPS,XRD,H2-TPR,O2-TPD和In-situ Mossbauer谱等方法表征了一系列组成不同的NaCl/B2O3/Fe2O3催化剂.结果表明NaCl与B2O3在修饰FeOx催化剂上存在明显的协同作用,B2O3调变了FeOx的还原能力,NaCl修饰了B2O3/FeOx使之具有很高的还原速度与晶格氧气化速度.催化剂的催化性能同这种协同作用密切相关.

关键词: NaCl/B2O3/Fe2O3, 甲烷氧化偶联, 协同作用, XPS, H2-TPR, O2-TPD

Abstract:

A series of NaCl/B2O3/Fe2O3 catalysts having a B/Fe atomic ratio from 0 to 0.3 and 0.25 of Na/Fe atomic ratio were prepared for the oxidative coupling of methane (OCM). It was noted that NaCl and B2O3 show a synergetic effect: NaCl/Fe2O3 produces mainly CO2, but B2O3/ Fe2O3 and B2O3/NaCl have poor activity. NaCl/B2O3/Fe2O3 catalyst has however high activity and selectivity. When the addition of B2O3 approaches 15 (at)%, the C2 yield and selectivity reach their maxima, 17% and 75% respectively. The C2H4/C2 ratio is as high as 76%. XRD, XPS, H2-TPR, O2-TPD and In-situ Mossbauer were employed to investigate the properties of the catalysts. Results show there is a synergetic effect between NaCl and B2O3 on FeOx surface. B2O3 modifies the redox ability of Fe2O3. The NaCl modified B2O3/FeOx has high reduction and lattice oxygen evaporation rates at 750℃. The high activity and selectivity of the NaCl/B2O3/FeOx catalyst are closely related with this synergetic effect.

Key words: NaCl/B2O3/Fex catalysts, Synergetic effect, Oxidative coupling of methane, XPS, H2-TPR and O2TPD