Epitaxial Oxide Interfaces Create Poison-Resistant CuO Sites for Environmental Catalysis

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Industrial exhaust streams contain multiple pollutants, including nitrogen oxides (NOx) and volatile organic compounds (VOCs).
• Existing catalysts for simultaneous NOx reduction and VOC oxidation face challenges like competitive adsorption, sulfur poisoning, and hydrogen cyanide (HCN) byproduct formation.
• Developing robust catalysts for multipollutant abatement is crucial for environmental protection.

Purpose of the Study:

• To engineer a novel catalyst that overcomes the limitations of current technologies for simultaneous NOx and VOC removal.
• To investigate the role of interfacial effects in enhancing catalytic activity, selectivity, and stability.
• To develop a poison-resistant catalytic system for industrial exhaust treatment.

Main Methods:

• Epitaxial stabilization of a CuO overlayer on Ti1-xInxO2.
• Characterization of interfacial properties, including strain and charge transfer.
• Evaluation of catalytic performance for NOx reduction and sulfur-containing VOC oxidation.
• Mechanistic studies using Eley-Rideal and Mars-van Krevelen pathways.

Main Results:

• The engineered CuO/Ti1-xInxO2 catalyst exhibits enhanced activity and selectivity for both NOx reduction and VOC oxidation.
• The oxide-oxide interface promotes electron-poor Cu-O sites and activates lattice oxygen, leading to improved catalytic performance.
• The catalyst demonstrates resistance to sulfur poisoning and suppresses HCN formation.
• Interfacial strain and charge transfer enhance Cu-O covalency and Lewis acidity, facilitating NOx reduction and VOC oxidation.

Conclusions:

• Epitaxial interfaces provide a general strategy for designing poison-resistant multipollutant catalysts.
• The developed catalyst offers a promising solution for treating complex industrial exhaust streams.
• This approach advances the field of heterogeneous catalysis for environmental applications.