REDOX CHEMISTRY IN EXCESSIVELY ION-EXCHANGED CU/NA-ZSM-5

被引:285
作者
SARKANY, J
DITRI, JL
SACHTLER, WMH
机构
[1] V.N. Ipatieff Laboratory, Center for Catalysis and Surface Science, Northwestern University, Evamton, 60208, IL
关键词
H+-INDUCED REOXIDATION; CU/NA-ZSM-5; CO; FTIR; TPR-TPD;
D O I
10.1007/BF00764336
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
TPR/TPD and FTIR arc used to characterize "excessively ion-exchanged" Cu/Na-ZSM-5. After calcination in O2 at 773 K at least two copper-oxygen species are present in addition to Cu2+ ions; these have been identified as CuO and [CU-O-Cu]2-. Reduction in H-2 transforms all these into Cu0 below 773 K. [Cu-O-Cu]2+ is autoreduced to Cu+ during outgassing. Reoxidation of Cu0 by zeolite protons to Cu+ is observed above 723 K in He or Ar; in the presence of CO this process is considerably enhanced and observed at much lower temperature, because CO is strongly adsorbed on Cu+. At 293 K CO adsorption causes reversible changes in the FTIR spectra.
引用
收藏
页码:241 / 249
页数:9
相关论文
共 33 条
  • [1] PREPARATION, SPECTROSCOPIC CHARACTERIZATION AND STABILITY OF SILICA-SUPPORTED COPPER(I) SPECIES
    AMARA, M
    BETTAHAR, M
    GENGEMBRE, L
    OLIVIER, D
    [J]. APPLIED CATALYSIS, 1987, 35 (01): : 153 - 168
  • [2] REACTIVE OXYGEN IN NACUX ZEOLITES
    BENN, FR
    DWYER, J
    ESFAHANI, A
    EVMERIDES, NP
    SZCZEPURA, AK
    [J]. JOURNAL OF CATALYSIS, 1977, 48 (1-3) : 60 - 72
  • [3] FT-IR STUDY OF THE SURFACE OF COPPER-OXIDE
    BUSCA, G
    [J]. JOURNAL OF MOLECULAR CATALYSIS, 1987, 43 (02): : 225 - 236
  • [4] EPR STUDY OF COPPER(II) ION PAIRS IN Y-TYPE ZEOLITES
    CHAO, CC
    LUNSFORD, JH
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1972, 57 (07) : 2890 - &
  • [5] ELECTRON-SPIN RESONANCE OF COPPER-EXCHANGED Y ZEOLITES .1. BEHAVIOR OF THE CATION DURING DEHYDRATION
    CONESA, JC
    SORIA, J
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1979, 75 : 406 - 422
  • [6] HYDROXYL-GROUPS AND ACID SITES IN NA-ZSM-5 ZEOLITES STUDIES BY IR SPECTROSCOPY
    DATKA, J
    TUZNIK, E
    [J]. ZEOLITES, 1985, 5 (04): : 230 - 232
  • [7] IR-SPECTRA OF CO AND NO ADSORBED ON CUO
    DAVYDOV, AA
    BUDNEVA, AA
    [J]. REACTION KINETICS AND CATALYSIS LETTERS, 1984, 25 (1-2): : 121 - 124
  • [8] DAVYDOV AA, 1985, KINET CATAL+, V26, P135
  • [9] DAVYDOV AA, 1978, KINET CATAL+, V19, P776
  • [10] ELEMENTARY STEPS IN THE FORMATION OF HIGHLY DISPERSED PALLADIUM IN NAY .1. PD ION COORDINATION AND MIGRATION
    HOMEYER, ST
    SACHTLER, WMH
    [J]. JOURNAL OF CATALYSIS, 1989, 117 (01) : 91 - 101