AN EXAFS STUDY OF CU/ZNO AND CU/ZNO-AL2O3 METHANOL SYNTHESIS CATALYSTS

被引:14
作者
ARUNARKAVALLI, T
KULKARNI, GU
RAO, CNR
机构
[1] INDIAN INST SCI,SOLID STATE & STRUCT CHEM UNIT,BANGALORE 560012,KARNATAKA,INDIA
[2] INDIAN INST SCI,CSIR,CTR EXCELLENCE CHEM,BANGALORE 560012,KARNATAKA,INDIA
关键词
EXAFS; XANES; METHANOL SYNTHESIS CATALYSTS; CU/ZNO; CU/ZNO-AL2O3;
D O I
10.1007/BF00769298
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
Cu K-absorption edge and EXAFS measurements on binary Cu/ZnO and ternary Cu/ZnO-Al2O3 catalysts of varying compositions on reduction with hydrogen at 523 K, show the presence of Cu microclusters and a species of Cu1+ dissolved in ZnO apart from metallic Cu and Cu2O. The proportions of different phases critically depend on the heating rate especially for catalysts of higher Cu content. Accordingly, hydrogen reduction with a heating rate of 10 K/min predominantly yields the metal species (>50%), while a slower heating rate of 0.8 K/min enhances the proportion of the Cu1+ species (approximately 60%). Reduced Cu/ZrnO-Al2O3 catalysts show the presence of metallic Cu (upto 20%) mostly in the form of microclusters and Cu1+ in ZnO as the major phase (approximately 60%). The addition of alumina to the Cu/ZnO catalyst seems to favour the formation of Cu1+/ZnO species.
引用
收藏
页码:259 / 268
页数:10
相关论文
共 16 条
  • [1] OPTICAL-PROPERTIES AND ELECTRONIC INTERACTIONS OF MICROCRYSTALLINE CU-ZNO CATALYSTS
    BULKO, JB
    HERMAN, RG
    KLIER, K
    SIMMONS, GW
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1979, 83 (24) : 3118 - 3122
  • [2] INSITU CELL FOR COMBINED XRD AND ONLINE CATALYSIS TESTS - STUDIES OF CU-BASED WATER GAS SHIFT AND METHANOL CATALYSTS
    CLAUSEN, BS
    STEFFENSEN, G
    FABIUS, B
    VILLADSEN, J
    FEIDENHANSL, R
    TOPSOE, H
    [J]. JOURNAL OF CATALYSIS, 1991, 132 (02) : 524 - 535
  • [3] X-RAY ABSORPTION-SPECTROSCOPY STUDY OF CU-BASED METHANOL CATALYSTS .1. CALCINED STATE
    CLAUSEN, BS
    LENGELER, B
    RASMUSSEN, BS
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1985, 89 (11) : 2319 - 2324
  • [4] SURFACE MOBILITY AND REACTIVITY OF OXYGEN SPECIES ON A COPPER-ZINC CATALYST IN METHANOL SYNTHESIS
    DUPREZ, D
    FERHATHAMIDA, Z
    BETTAHAR, MM
    [J]. JOURNAL OF CATALYSIS, 1990, 124 (01) : 1 - 11
  • [5] CATALYTIC SYNTHESIS OF METHANOL FROM CO-H2 .1. PHASE COMPOSITION, ELECTRONIC PROPERTIES, AND ACTIVITIES OF THE CU-ZNO-M2O3 CATALYSTS
    HERMAN, RG
    KLIER, K
    SIMMONS, GW
    FINN, BP
    BULKO, JB
    KOBYLINSKI, TP
    [J]. JOURNAL OF CATALYSIS, 1979, 56 (03) : 407 - 429
  • [6] X-RAY ABSORPTION-EDGE AND EXAFS STUDY OF THE COPPER SITES IN ZNO METHANOL SYNTHESIS CATALYSTS
    KAU, LS
    HODGSON, KO
    SOLOMON, EI
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (18) : 7103 - 7109
  • [7] CATALYTIC SYNTHESIS OF METHANOL FROM CO/H2 .4. THE EFFECTS OF CARBON-DIOXIDE
    KLIER, K
    CHATIKAVANIJ, V
    HERMAN, RG
    SIMMONS, GW
    [J]. JOURNAL OF CATALYSIS, 1982, 74 (02) : 343 - 360
  • [8] METHANOL SYNTHESIS
    KLIER, K
    [J]. ADVANCES IN CATALYSIS, 1982, 31 : 243 - 313
  • [9] AN INSITU EXAFS INVESTIGATION OF BIMETALLIC CU-NI/GAMMA-AL2O3 CATALYSTS
    KULKARNI, GU
    SANKAR, G
    RAO, CNR
    [J]. JOURNAL OF CATALYSIS, 1991, 131 (02) : 491 - 501
  • [10] KULKARNI GU, 1989, Z PHYS B, V7, P529