Study on activity, stability limit and reaction mechanism of CO self-sustained combustion over the LaMnO3, La0.9Ce0.1MnO3 and La0.9Sr0.1MnO3 perovskite catalysts using sugar agent
Study on activity, stability limit and reaction mechanism of CO self-sustained combustion over the LaMnO3, La0.9Ce0.1MnO3 and La0.9Sr0.1MnO3 perovskite catalysts using sugar agent
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糖剂LaMnO3、La0.9Ce0.1MnO3、La0.9Sr0.1MnO3钙钛矿催化剂CO自续燃烧活性、稳定性极限及反应机理研究
DOI：
10.1016/j.fuel.2021.120289
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发表时间：
2021-02-16
期刊：
影响因子：
7.4
通讯作者：
Dou, Baojuan
中科院分区：
文献类型：
--
作者：
Huang, Junqin;Teng, Zihao;Dou, Baojuan
采用糖剂法合成了LaMnO 3、La0.9Ce0.1MnO3和La0.9Sr0.1MnO3催化剂，考察了温度对催化剂CO自持燃烧性能的影响，CO转化率分别为10%（T10）、50%（T50）和90%（T90）。结果表明，在该催化剂上成功地实现了自持燃烧，活性降低的顺序为：La0.9Ce0.1MnO3（有糖）> La0.9Sr0.1MnO3（有糖）> LaMnO 3（有糖）> LaMnO 3（无糖）> La0.9Sr0.1MnO3（无糖）> La0.9Ce0.1MnO3（无糖）。结合XPS、H2-TPR、O2-TPD和CO-TPD等技术的结果，认为La0.9Ce0.1MnO3（含糖）催化剂的优异活性是由于其表面富集了大量的Mn ~（4+）离子和活性氧空位，低温还原良好，分散均匀。此外，原位红外光谱结果表明，CO在锰基钙钛矿催化剂上的催化燃烧遵循L-H机理：CO和O2发生化学吸附，生成单齿碳酸盐和碳酸氢盐物种，然后分解产生CO2释放。高温稳定性试验表明，La0.9Ce0.1MnO3（含糖）的CO转化率为100%，反应12 h后活性基本不变，催化剂床层温度达到717 ℃左右。C.研究结果有助于钢铁行业采用该技术实现能源的高效、清洁利用。
The LaMnO3, La0.9Ce0.1MnO3 and La0.9Sr0.1MnO3 catalysts are synthesized using sugar agent, and the CO selfsustained combustion is investigated, where the catalytic performance is decided by temperature with CO conversions of 10% (T10), 50% (T50), and 90% (T90). The results show that self-sustaining combustion is successfully realized on the catalyst, and the order of activity decrease is as follows: La0.9Ce0.1MnO3 (with sugar) > La0.9Sr0.1MnO3 (with sugar) > LaMnO3 (with sugar) > LaMnO3 (without sugar) > La0.9Sr0.1MnO3 (without sugar) > La0.9Ce0.1MnO3 (without sugar). Combined with the results of XPS, H2-TPR, O2-TPD and CO-TPD techniques, the excellent activity of La0.9Ce0.1MnO3 (with sugar) can be attributed to the high content of Mn4+ ions and reactive oxygen vacancies enriched on the catalyst surface, sound low-temperature reduction, and uniform dispersion. Besides, in situ IR spectroscopy results indicate that the catalytic combustion of CO over manganese-based perovskite catalysts follows the L-H mechanism: the chemisorption of CO and O2 takes place to produce monodentate carbonates and bicarbonate species, which then decompose to yield CO2 release. The hightemperature stability test provides evidence that the La0.9Ce0.1MnO3 (with sugar) gives 100% CO conversion and that the activities remain almost unchanged after reaction for 12 h, where the temperature of catalyst bed reaches about 717 ?C. The results obtained are helpful to accept this technology on efficient and clean energy utilization in iron and steel industry.