Single transition metal anchored C₉N₄ sheets as an efficient catalyst for CO oxidation: a first-principles study

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Single-atom catalysts (SACs) offer high atom utilization and excellent catalytic activity.
• Carbon monoxide (CO) oxidation is crucial for mitigating pollution from fossil fuel combustion.

Purpose of the Study:

• To investigate the catalytic activity of transition metal single-atom catalysts (Co@C9N4 and Ni@C9N4) for CO oxidation.
• To compare the performance of Co and Ni anchored on C9N4 substrates for efficient carbon monoxide oxidation.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to compare adsorption energies of O2 and CO on TM@C9N4.
• Analysis of reaction mechanisms including Eley-Rideal, New Eley-Rideal, Ter-molecular Eley-Rideal, and Langmuir-Hinshelwood.
• Calculation of kinetic energy barriers for CO oxidation on Co@C9N4 and Ni@C9N4.

Main Results:

• Co and Ni anchored at the C9N4 cavity exhibit high catalytic activity for CO oxidation.
• Co@C9N4 shows kinetic energy barriers ranging from 0.19 eV to 0.54 eV.
• Ni@C9N4 demonstrates kinetic energy barriers from 0.26 eV to 0.44 eV.

Conclusions:

• Co/Ni@C9N4 catalysts exhibit superior stability and activity for oxidizing CO.
• These findings provide insights into efficient catalysts for reducing CO emissions from incomplete combustion of fossil fuels.