Mo₆S₈-based single-metal-atom catalysts for direct methane to methanol conversion

Area of Science:

• Heterogeneous Catalysis
• Materials Science
• Computational Chemistry

Background:

• Single atom catalysts (SACs) are gaining prominence in catalysis due to their high atom utilization efficiency.
• Direct methane to methanol conversion is a crucial but challenging process for utilizing natural gas.
• The Mo₆S₈ cluster is a potential support material for catalytic applications.

Purpose of the Study:

• To investigate the effect of single-metal-atom doping on the Mo₆S₈ cluster for direct methane to methanol conversion.
• To identify the most effective dopant and understand the underlying catalytic mechanisms.
• To explore the interplay of ensemble and confinement effects in single atom catalysis.

Main Methods:

• Density functional theory (DFT) calculations were employed to study the electronic and catalytic properties.
• Simulations focused on the steam reforming of methane (SRM) pathway over doped Mo₆S₈ clusters.
• Analysis of reaction intermediates, transition states, and binding energies was performed.

Main Results:

• All single metal atom dopants (K, Ti, Fe, Co, Ni, Cu, Rh) facilitated methane to methanol conversion via SRM.
• The Fe-Mo₆S₈ catalyst exhibited the highest activity and selectivity for methanol production.
• The enhanced performance is attributed to the synergistic ensemble and confinement effects introduced by the single dopant atom.

Conclusions:

• Single atom doping significantly promotes methane to methanol conversion over Mo₆S₈ clusters.
• The Fe-Mo₆S₈ system demonstrates superior catalytic activity, highlighting Fe as a promising dopant.
• Optimizing dopant-ligand interactions and confinement effects is key for designing efficient single atom catalysts for SRM.