Applied Catalysis2022，Vol.30916.DOI:10.1016/j.apcatb.2022.121249

Investigation into the catalytic roles of oxygen vacancies during gaseous styrene degradation process via CeO2 catalysts with four different morphologies

Zhang, Ying Lu, Jichang Zhang, Liming Fu, Te Zhang, Jin Zhu, Xing Gao, Xiaoya He, Dedong Luo, Yongming Dionysiou, Dionysios D. Zhu, Wenjie
Applied Catalysis2022，Vol.30916.DOI:10.1016/j.apcatb.2022.121249
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  • NSTL
  • Elsevier

Investigation into the catalytic roles of oxygen vacancies during gaseous styrene degradation process via CeO2 catalysts with four different morphologies

Zhang, Ying 1Lu, Jichang 1Zhang, Liming 1Fu, Te 1Zhang, Jin 2Zhu, Xing 1Gao, Xiaoya 1He, Dedong 3Luo, Yongming 1Dionysiou, Dionysios D. 4Zhu, Wenjie1
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作者信息

  • 1. Kunming Univ Sci & Technol
  • 2. Yunnan Univ
  • 3. Innovat Team Volatile Organ Cpds Pollutants Contr
  • 4. Univ Cincinnati
  • 折叠

Abstract

CeO2 catalysts with four different morphologies (sphere, rod, octahedral and cube) were successfully synthesized under hydrothermal conditions and showed quite different thermocatalytic activities for gaseous styrene degradation. Unexpectedly, even though its main exposed lattice plane was (111), spherical CeO2 (CeO2-S), presented the highest styrene catalytic degradation activity (T-90 =184 degrees C) with a styrene degradation rate of 1.36 x 10(-3) molstyrene g(-1) h(-1) at 200 degrees C that was approximately 12 times higher than that of cubic CeO2. A comprehensive structural characterization and mechanistic study found that the four CeO2 samples exhibit different degrees of lattice distortion and different oxygen vacancy concentrations. CeO2-S has the greatest lattice distortion, resulting in abundant oxygen vacancies. Oxygen vacancies were identified to be the main active sites through increasing reactive oxygen generation. Meanwhile, styrene was activated by adsorption of oxygen vacancies. Based on the results of in-situ DRIFTS and XPS measurements, O-18(2) isotope tracing experiment and DFT theoretical calculations, the superior thermocatalytic performance of CeO2-S can be attributed to the lesser accumulation of intermediates on its surface, which follows the Langmuir-Hinshelwood (L-H) mechanism (low temperature) and the Mars-van Krevelen (MVK) mechanism (high temperature). In addition, no obvious decrease was observed in the activity of the CeO2-S catalyst for styrene degradation at 210 degrees C in the presence of water vapor, which is beneficial for the actual industrial application.

Key words

Cerium dioxide/Low temperature catalytic oxidation of gaseous styrene/Oxygen vacancies/Reaction mechanism/Water resistance/PREFERENTIAL OXIDATION/OXIDE CATALYSTS/HYDROXYL-GROUPS/CO/PERFORMANCE/HYDROGENATION/SPECTROSCOPY/MECHANISM/NANORODS

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出版年

2022
Applied Catalysis

Applied Catalysis

ISSN：0926-3373
被引量53
参考文献量53
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