摘要
The mixed ionic-electronic conducting (MIEC) materials that have been developed for catalytic membrane reactors are vulnerable to a reducing atmosphere, especially H2. We reported on a MIEC oxide, Sr 0.7Ba0.3Fe0.9Mo0.1O 3-δ (SBFM), with a cubic perovskite structure (a = 3.91 Å at room temperature). SBFM can maintain full perovskite structure in a 5 vol % H2/He atmosphere at 900 °C even for 50 h. The high reduce-tolerant property was mainly attributed to the synergistic effect between Mo(VI)/Mo(V) and Fe3+/Fe2+ couples. SBFM also exhibited good tolerance to a CO2 atmosphere at high temperature (≥900 °C) but reacted with CO2 at relatively low temperature (<800 °C). The introduction of Mo ion into the Fe site greatly improved the thermal stabilization of the SBFM oxide. The average thermal expansion coefficients in nitrogen atmosphere were 12.8 × 10-6 and 20.8 × 10-6 °C -1 in the temperature ranges of 200-600 and 600-900 °C, respectively. At 900 °C, the oxygen permeation flux of SBFM membrane (1 mm in thickness) was 4.39 × 10-7 mol cm-2 s-1. The oxygen permeation activation energy (E a) was 42 kJ mol-1, which was significantly lower than that of commonly used MIEC membranes.
源语言 | 英语 |
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页(从-至) | 3610-3618 |
页数 | 9 |
期刊 | Chemistry of Materials |
卷 | 22 |
期 | 12 |
DOI | |
出版状态 | 已出版 - 22 6月 2010 |