AN EXAFS AND XANES STUDY OF EUROPIUM-NICKEL-EXCHANGED AND EUROPIUM-NICKEL-EXCHANGED Y-ZEOLITE AND THE EFFECTS OF REDUCTION

被引:4
作者
BERRY, FJ
MARCO, JF
STEEL, AT
机构
[1] UNIV BIRMINGHAM,SCH CHEM,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND
[2] CSIC,INST QUIM FIS ROCASOLANO,MADRID 6,SPAIN
[3] UNILEVER RES,PORT SUNLIGHT LAB,MERSEYSIDE,ENGLAND
来源
ZEOLITES | 1994年 / 14卷 / 05期
关键词
EUROPIUM-EXCHANGED Y-ZEOLITE; EXAFS; XANES; MOSSBAUER SPECTROSCOPY;
D O I
10.1016/0144-2449(94)90107-4
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
Eu3+ within the supercages of a ca. 10 wt% europium-exchanged Y zeolite of composition [Eu7.8(NH4)30.5Na0.1Si139Al530384].nH2O can be partially reduced by hydrogen to Eu2+. XANES is shown to be a particularly sensitive means by which the reduction process can be monitored. The Eu3+ in similar sites in a ca. 3 wt% europium-1.5 wt% nickel coexchanged Y zeolite of composition [Eu2.3Ni3.0(NH4)41Na0.1Si141Al51O334].nH2O is also amenable to partial hydrogen reduction to Eu2+. Some of the reduced species, probably located in the smaller cages as a result of migration during the reduction process, are resistant to reoxidation. The Ni2+ in the supercages of the coexchanged Y zeolite is more amenable to hydrogen reduction to metallic nickel than is Ni2+-exchanged Y zeolite in which the Ni2+ is located in the smaller cages.
引用
收藏
页码:344 / 348
页数:5
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