Sulfate species in MgO-supported LaMn0.5Mg0.5O3 perovskites:: An insight into the chemistry of MgO

被引：7

作者：

Rosso, I ^{[1
]}

Fiorilli, S ^{[1
]}

Onida, B ^{[1
]}

Saracco, G ^{[1
]}

Garrone, E ^{[1
]}

机构：

[1] Politecn Torino, Dipartimento Sci Mat & Ingn Chim, I-10129 Turin, Italy

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2002年 / 106卷 / 46期

关键词：

D O I：

10.1021/jp0257808

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 structure, thermal stability, and reducibility in H-2 of sulfate species formed in MgO-promoted perovskites, LaMn0.5Mg0.5O3.17 MgO, have been studied by infrared spectroscopy, temperature-programmed desorption, and temperature-programmed reduction-mass spectrometry. Sulfation at 1073 K generates on the MgO phase both bulk and subsurface sulfates, whereas the latter species are the major product of sulfation at room temperature. In contrast with high-surface MgO samples (where sulfate species of covalent nature are found), the surface species closely resemble those in the bulk. Bulk sulfates are more resistant to thermal treatments than surface sulfates. A transformation of bulk sulfates at higher temperature into sulfides is suggested by IR spectroscopy and proved by chemical analysis. SO2, SO, and H2S are the products of sulfate reduction.

引用

页码：11980 / 11984

页数：5

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