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Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
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Oxygen vacancy-mediated Mn2O3 catalyst with high efficiency and stability for toluene oxidation
Xueqin Yang1, Ziqing Ma1, Dadao Wang1
1College of Forestry, Henan Agricultural University, Zhengzhou 450046, PR China.
Journal of Colloid and Interface Science
|July 13, 2024
Summary
Creating defect-rich manganese oxide (Mn₂O₃) catalysts by controlling calcination temperature enhances their performance in catalytic reactions. Low-temperature synthesis generates oxygen vacancies, boosting activity and stability for applications like toluene oxidation.
Area of Science:
- Materials Science
- Catalysis
- Surface Chemistry
Background:
- Oxygen vacancy engineering in transition metal oxides is a key strategy for enhancing catalytic activity.
- Manganese oxides (Mn₂O₃) are promising catalysts, but their performance can be limited by surface properties.
Purpose of the Study:
- To construct defect-rich Mn₂O₃ catalysts by controlling calcination temperature.
- To investigate the effect of oxygen vacancies on catalytic performance, particularly for toluene oxidation.
- To evaluate the stability and durability of the engineered catalysts.
Main Methods:
- Synthesis of Mn₂O₃ catalysts via controlled calcination temperatures.
- Characterization of oxygen vacancy content and oxidation states (e.g., Mn⁴⁺).
- Density Functional Theory (DFT) calculations to study adsorption energies and reaction mechanisms.
- Catalytic performance testing (activity, activation energy, stability, water tolerance).
- In situ DRIFTS spectroscopy to analyze reaction intermediates under varying conditions.
Main Results:
- Low-temperature calcination (e.g., Mn₂O₃-300) generated abundant oxygen vacancies and Mn⁴⁺ ions.
- Defective Mn₂O₃ exhibited enhanced low-temperature reducibility and surface oxygen migration.
- DFT calculations confirmed favorable adsorption of O₂ and toluene on defective facets, activating the OO bond.
- The Mn₂O₃-300 catalyst showed the highest reaction rate, lowest activation energy, and excellent stability, water tolerance, and CO₂ yield.
- In situ DRIFTS confirmed minimal impact of water vapor on reaction intermediates, indicating robust durability.
Conclusions:
- Controlled calcination is an effective method to engineer oxygen vacancies in Mn₂O₃ for improved catalytic performance.
- The presence of oxygen vacancies significantly enhances toluene oxidation activity and catalyst stability.
- Defect-rich Mn₂O₃ catalysts demonstrate excellent durability and resistance to water, making them suitable for practical applications.
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