Less Is More: Selective-Atom-Removal-Derived Defective MnO_x Catalyst for Efficient Propane Oxidation

Area of Science:

• Materials Science
• Catalysis
• Chemical Engineering

Background:

• Defect engineering in metal oxides is crucial for enhancing catalytic activity.
• Propane oxidation requires efficient and stable catalysts, particularly for low-temperature applications.

Purpose of the Study:

• To develop a defective manganese oxide catalyst using a selective atom removal strategy.
• To investigate the impact of defect engineering on the catalytic performance and stability for propane oxidation.

Main Methods:

• Selective etching of Mg dopant in MnO_x to create defective MgMnO_x-H.
• Characterization using experimental techniques to analyze defect structures.
• Evaluation of catalytic activity and hydrothermal stability for propane oxidation.

Main Results:

• The MgMnO_x-H catalyst demonstrated superior low-temperature activity (T₅₀ = 185 °C, T₉₀ = 226 °C) and a 4.8-fold increase in propane conversion rate compared to pristine MnO_x.
• The catalyst exhibited excellent hydrothermal stability, maintaining performance at 250 °C for 30 hours.
• Defective structures, including vacancies and distorted crystals, were found to weaken Mn-O bonds and enhance lattice oxygen mobility, boosting intrinsic oxidation activity.

Conclusions:

• Defect engineering is a significant strategy for improving the oxidation ability of metal oxides.
• The developed defective manganese oxide catalyst shows great potential for efficient propane oxidation.
• This work provides valuable insights for designing advanced non-noble metal catalysts.