SIZE EFFECTS IN ETHYLENE OXIDATION ON SILVER CATALYSTS - INFLUENCE OF SUPPORT AND CS PROMOTER

被引：93

作者：

GONCHAROVA, SN ^{[1
]}

PAUKSHTIS, EA ^{[1
]}

BALZHINIMAEV, BS ^{[1
]}

机构：

[1] RUSSIAN ACAD SCI, BORESKOV INST CATALYSIS, SIBERIAN BRANCH, NOVOSIBIRSK 630090, RUSSIA

来源：

APPLIED CATALYSIS A-GENERAL | 1995年 / 126卷 / 01期

关键词：

ETHYLENE EPOXIDATION; ETHYLENE PI-COMPLEX; SILVER CATALYST; SILVER PARTICLE SIZE DISTRIBUTION; SIZE EFFECT;

D O I：

10.1016/0926-860X(95)00036-4

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：

A new method for preparing supported silver catalysts with a narrow particle size distribution has been developed. For crystals with a diameter ranging from 100 to 1000 Angstrom the dependencies of reaction rates on size have been studied for epoxidation and deep oxidation of ethylene. For particles 300-500 Angstrom in size the reaction rate was found to increase sharply. The concentration of ethylene pi-complexes with Ag+ cations increased proportionally to the reaction rate. These pi-complexes are assumed to be the only intermediates directing the reaction towards epoxidation. The ratio of the reaction rate to the concentration of pi-complexes was found to remain constant within a wide range of AE crystal sizes including bulk silver samples. The influence of the support (alpha-Al2O3, SiO2) on the size effect relates to the secondary processes of ethylene oxide conversion. The factors that cause the catalytic size effect and the promoting effect of Cs are discussed.

引用

页码：67 / 84

页数：18

共 41 条

[31] CHEMISORPTION OF OXYGEN ON SILVER (111) SURFACE
ROVIDA, G
PRATESI, F
MAGLIETTA, M
FERRONI, E
[J]. SURFACE SCIENCE, 1974, 43 (01) : 230 - 256
[32] THE BEHAVIOR OF MODEL AG/AL2O3 CATALYSTS IN VARIOUS CHEMICAL ENVIRONMENTS
RUCKENSTEIN, E
LEE, SH
[J]. JOURNAL OF CATALYSIS, 1988, 109 (01) : 100 - 119
[33] STRUCTURE SENSITIVITY OF THE CATALYTIC-OXIDATION OF ETHENE BY SILVER
SAJKOWSKI, DJ
BOUDART, M
[J]. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING, 1987, 29 (04): : 325 - 360
[34] ETHYLENE OXIDATION OVER SMALL SILVER CRYSTALLITES
SEYEDMONIR, SR
PLISCHKE, JK
VANNICE, MA
YOUNG, HW
[J]. JOURNAL OF CATALYSIS, 1990, 123 (02) : 534 - 549
[35] Sokolov V. S., 1987, KINET KATAL, V28, P398
[36] SVERDLOV LM, 1970, VIBRATION SPECTRA MU, P154
[37] VANSANTEN RA, 1988, CATALYSIS THEORY PRA, P1152
[38] INFLUENCE OF METAL CRYSTALLITE SIZE AND MORPHOLOGY ON SELECTIVITY AND ACTIVITY OF ETHYLENE OXIDATION CATALYZED BY SUPPORTED SILVER
VERYKIOS, XE
STEIN, FP
COUGHLIN, RW
[J]. JOURNAL OF CATALYSIS, 1980, 66 (02) : 368 - 382
[39] EFFECT OF CRYSTALLITE SIZE ON ACTIVITY AND SELECTIVITY OF SILVER CATALYSTS
WU, JC
HARRIOTT, P
[J]. JOURNAL OF CATALYSIS, 1975, 39 (03) : 395 - 402
[40] [No title captured]

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