Probing the Atomistic Reaction Pathways in CuO/C Catalysts.

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Copper oxide (CuO)/carbon (C) catalysts exhibit excellent low-temperature denitration (de-NOx) activity.
• A fundamental understanding of the CuO-C reaction is essential for optimizing CuO/C catalyst performance.

Purpose of the Study:

• To investigate the atomic-scale reaction mechanisms between CuO and C.
• To elucidate the role of the volume ratio in determining reaction pathways.
• To provide insights for designing advanced de-NOx catalysts.

Main Methods:

• Utilized transmission electron microscopy (TEM) with an in situ heating device.
• Employed first-principle calculations to interpret atomistic reduction pathways.

Main Results:

• Identified two distinct reaction mechanisms based on the CuO/C volume ratio.
• Mechanism 1 (<~31% ratio): Reduction of CuO to Cu2O.
• Mechanism 2 (>~34% ratio): Reduction of CuO to polycrystalline Cu.
• Atomistic pathways explained by oxygen vacancy diffusion.

Conclusions:

• The study reveals critical insights into the atomic-scale reaction between CuO and C.
• The volume ratio significantly dictates the reduction pathway of CuO.
• Findings pave the way for the rational design of efficient industrial de-NOx catalysts.