NO dissociation on Cu(111) and Cu2O(111) surfaces: a density functional theory based study

Area of Science:

• Computational Chemistry
• Surface Science
• Catalysis

Background:

• Nitrogen oxides (NOx) are significant air pollutants.
• NO dissociation is a critical, rate-limiting step in NOx reduction processes.
• Copper-based catalysts are explored for their potential in NOx abatement.

Purpose of the Study:

• To investigate the dissociation of nitric oxide (NO) on copper (Cu)(111) and copper(II) oxide (Cu(2)O)(111) surfaces.
• To evaluate the feasibility of using Cu-based catalysts for efficient NO dissociation in NOx reduction.
• To understand the surface interactions governing NO adsorption and dissociation pathways.

Main Methods:

• Spin-polarized density functional theory (DFT) calculations were employed.
• Analysis of reaction pathways, transition states, and adsorption energies.
• Investigation of the geometric and electronic structure of the catalyst surfaces.

Main Results:

• NO dissociation is energetically feasible on both Cu(111) and Cu(2)O(111) surfaces.
• The NO-Cu(2)O(111) system exhibits a favorable reaction pathway with a low-lying transition state, indicating facile dissociation.
• On the Cu(111) surface, NO desorption is predicted to be more favorable than dissociation.
• The unique electronic structure of Cu(2)O(111), influenced by subsurface oxygen, enhances NO adsorption and dissociation.

Conclusions:

• The Cu(2)O(111) surface demonstrates significant potential as a catalyst for NO dissociation.
• The electronic and geometric modifications of the Cu(2)O(111) surface are crucial for its catalytic activity.
• This study provides insights into designing effective copper-based catalysts for NOx reduction.