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

被引：96

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

[1]

BELLAMY LD, 1968, ADV INFRARED GROUP F, P54

[2] XPS AND UPS STUDIES OF OXYGEN-ADSORPTION OVER CLEAN AND CARBON-MODIFIED SILVER SURFACES [J].

BORONIN, AI ;

BUKHTIYAROV, VI ;

VISHNEVSKII, AL ;

BORESKOV, GK ;

SAVCHENKO, VI .

SURFACE SCIENCE, 1988, 201 (1-2) :195-210

[3] OXYGEN-ADSORPTION ON AG POWDER [J].

BOWKER, M ;

PUDNEY, P ;

ROBERTS, G .

JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1989, 85 :2635-2640

[4] 2 OXYGEN STATES AND THE ROLE OF CARBON IN PARTIAL OXIDATION OF ETHYLENE OVER SILVER [J].

BUKHTIYAROV, VI ;

BORONIN, AI ;

SAVCHENKO, VI .

SURFACE SCIENCE, 1990, 232 (1-2) :L205-L209

[5]

BUKHTIYAROV VI, IN PRESS J PHYS CHEM

[6] TRANSIENT-RESPONSE AND INFRARED STUDIES OF ETHYLENE-OXIDE REACTIONS ON SILVER CATALYSTS AND SUPPORTS [J].

BULUSHEV, DA ;

PAUKSHTIS, EA ;

NOGIN, YN ;

BALZHINIMAEV, BS .

APPLIED CATALYSIS A-GENERAL, 1995, 123 (02) :301-322

[7]

CAMPBELL CT, 1985, J CATAL, V92, P364

[8] THE INFLUENCE OF PARTICLE-SIZE ON THE CATALYTIC PROPERTIES OF SUPPORTED METALS [J].

CHE, M ;

BENNETT, CO .

ADVANCES IN CATALYSIS, 1989, 36 :55-172

[9]

CHEIPHEZ LI, 1982, KHIMIYA, P279

[10] OXIDATION OF ETHYLENE CATALYZED BY SILVER SUPPORTED ON ZIRCONIUM-PHOSPHATE - PARTICLE-SIZE AND SUPPORT EFFECT [J].

CHENG, S ;

CLEARFIELD, A .

JOURNAL OF CATALYSIS, 1985, 94 (02) :455-467

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