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

Junqin Huang, Zihao Teng, Running Kang, Feng Bin, Xiaolin Wei, Qinglan Hao, Kwun Nam Hui, Kwan San Hui, Baojuan Dou

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2 Citations (Scopus)

Abstract

The LaMnO 3, La 0.9Ce 0.1MnO 3 and La 0.9Sr 0.1MnO 3 catalysts are synthesized using sugar agent, and the CO self-sustained combustion is investigated, where the catalytic performance is decided by temperature with CO conversions of 10% (T 10), 50% (T 50), and 90% (T 90). The results show that self-sustaining combustion is successfully realized on the catalyst, and the order of activity decrease is as follows: La 0.9Ce 0.1MnO 3 (with sugar) > La 0.9Sr 0.1MnO 3 (with sugar) > LaMnO 3 (with sugar) > LaMnO 3 (without sugar) > La 0.9Sr 0.1MnO 3 (without sugar) > La 0.9Ce 0.1MnO 3 (without sugar). Combined with the results of XPS, H 2-TPR, O 2-TPD and CO-TPD techniques, the excellent activity of La 0.9Ce 0.1MnO 3 (with sugar) can be attributed to the high content of Mn 4+ 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 O 2 takes place to produce monodentate carbonates and bicarbonate species, which then decompose to yield CO 2 release. The high-temperature stability test provides evidence that the La 0.9Ce 0.1MnO 3 (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.

Original languageEnglish
Article number120289
JournalFuel
Volume292
Early online date16 Feb 2021
DOIs
Publication statusPublished - 15 May 2021

Keywords

  • Carbon monoxide
  • Perovskite
  • Self-sustained combustion
  • Stability limit
  • Sugar agent

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