STRUCTURE AND REACTIVITY OF AMMONIA-SYNTHESIS CATALYSTS DERIVED FROM CERU2 PRECURSORS - A STUDY BY INSITU X-RAY ABSORPTION-SPECTROSCOPY

被引：15
作者：
WALKER, AP
RAYMENT, T
LAMBERT, RM
OLDMAN, RJ
机构：
[1] UNIV CAMBRIDGE,DEPT CHEM,CAMBRIDGE CB2 1EW,ENGLAND
[2] ICI CHEM & POLYMERS,RES & TECH,RUNCORN CB2 1EW,CHESHIRE,ENGLAND
来源：
JOURNAL OF CATALYSIS | 1990年 / 125卷 / 01期
关键词：
D O I：
10.1016/0021-9517(90)90078-X
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：
The activation, steady-state performance, and poisoning of efficient ammonia synthesis catalysts derived from a CeRu2 precursor have been studied by in situ X-ray absorption spectroscopy at 50 bar pressure and at temperatures up to 450°C. The EXAFS and near-edge data supported by earlier XRD studies under identical conditions indicate that the active phase consists of ultradispersed, electron-rich Ru entities with low metal-metal coordination and in intimate contact with the CeH2+x support. Oxidation of this material yields CeO2/Ru; this system is catalytically inert and exhibits none of the unusual structural or electronic properties of the active CeH2+x/Ru catalyst. © 1990.
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页码：67 / 76
页数：10
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