期刊
JOURNAL OF PHYSICAL CHEMISTRY C
卷 118, 期 4, 页码 1999-2010出版社
AMER CHEMICAL SOC
DOI: 10.1021/jp410207d
关键词
-
资金
- National Science Foundation of China (NSFC) [21076211, 21206159, 11205160]
- Science Foundation of Northwest University [12NW14]
Compared to Ba-hexaaluminates with beta-Al2O3 structure, La-hexaaluminates with magnetoplumbite (MP) structure have more substituted Al sites in the preferentially exposed mirror plane, which should favor N2O decomposition. In this regard, LaFexAl12-xO19 catalysts with x = 1 and 5 were herein prepared using the coprecipitation method. Fe-57 Mossbauer spectroscopy and X-ray diffraction structure refinements revealed that Fe3+ ions originating in Fe2O3 species mainly entered tetrahedral Al(2) and trigonal bipyramidal Al(5) sites. Meanwhile, Fe3+ ions in octahedral sites of perovskite-type LaFeO3 intermediates preferentially accommodated in octahedral Al(3) sites in the mirror plane of La-hexaaluminates. Correlation of normalized rates (moles of N2O per hour per square meter) of the catalysts at 500 degrees C with the occupancy of Fe ions in different Al crystallographic sites of the MP phase indicated that Fe3+ ions in the Al(3) and Al(5) sites were highly active for N2O decomposition. In contrast, Fe2+ derived from a Fe3+ -> Fe2+ reduction under high-temperature calcination played a negative role.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据