Catalytic oxidation of CH₄ into CH₃OH using C₂₄N₂₄-supported single-atom catalyst

Area of Science:

• Computational Chemistry
• Materials Science
• Catalysis

Background:

• Methane (CH4) is an abundant but underutilized energy resource due to transport challenges.
• Methanol (CH3OH) is a valuable chemical feedstock and a promising alternative fuel.
• Developing efficient catalysts for methane oxidation to methanol is crucial for sustainable energy.

Purpose of the Study:

• To investigate the stability and catalytic activity of transition metal (TM) atoms (Ti, V) integrated into C24N24 cages for methane oxidation.
• To elucidate the reaction mechanism for converting methane to methanol using TM@C24N24 single-atom catalysts with N2O as the oxidant.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study the electronic structure and stability of TM@C24N24 systems.
• The catalytic pathway for methane oxidation was simulated, including adsorption, decomposition of N2O, and subsequent methane conversion steps.
• Reaction barriers for key steps, such as C-H bond activation and methanol formation, were calculated.

Main Results:

• TM@C24N24 structures (Ti@C24N24 and V@C24N24) exhibit significant stability, with binding energies more negative than cohesive energies.
• N2O effectively adsorbs and decomposes on TM@C24N24, generating adsorbed oxygen (Oads) as the active species for methane oxidation.
• The catalytic process involves low reaction barriers for methane activation (1.2-1.5 eV) and methanol formation (1.8 eV), with efficient methanol desorption (1.0-1.4 eV).

Conclusions:

• TM@C24N24 single-atom catalysts demonstrate excellent stability and potential for efficient methane-to-methanol conversion.
• The proposed catalytic mechanism using N2O as an oxidant provides a viable route for producing methanol from methane.
• These findings offer valuable theoretical insights for designing advanced catalysts for sustainable energy applications.