Methane activation on single-atom Ir-doped metal nanoparticles from first principles

Area of Science:

• Heterogeneous catalysis
• Surface science
• Computational chemistry

Background:

• Methane (CH4) activation is crucial for various chemical processes.
• Altering surface electronic structures via doping or stoichiometry control enhances catalytic efficiency.
• Understanding methane activation mechanisms on metal surfaces is key for catalyst design.

Purpose of the Study:

• To investigate methane activation on pure metal and single-atom iridium-doped alloy nanoparticles.
• To elucidate the role of surface structure and doping on C-H bond dissociation barriers.
• To identify efficient catalysts for methane activation at the atomic level.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Construction of nanoparticle models based on (100), (110), and (111) surfaces.
• Application of DFT-based transition state theory to determine reaction rates.

Main Results:

• Iridium-doped alloy surfaces exhibited significantly lower CH4 dissociation barriers (0.3-0.4 eV) compared to pure metal surfaces (0.6-0.8 eV).
• Single-atom iridium doping effectively lowers the energy barrier for the first C-H bond activation.
• The (110) surface facet proportion strongly influences the temperature dependence of methane activation.

Conclusions:

• Single-atom iridium-doped platinum nanoparticles are highly efficient catalysts for methane activation.
• The findings provide atomic-level insights for designing novel metal catalysts for methane conversion.
• This research has potential implications for industrial applications requiring efficient methane utilization.