Engineering electronic platinum-carbon support interaction to tame carbon monoxide activation

Area of Science:

• Heterogeneous catalysis
• Surface chemistry
• Materials science

Background:

• Carbon monoxide (CO) oxidation is crucial but its molecular-level mechanisms on platinum-carbon catalysts are not fully understood.
• Electronic metal-support interactions significantly influence catalytic activity, yet their precise role in CO oxidation remains elusive.

Purpose of the Study:

• To elucidate the mechanistic and kinetic picture of CO oxidation on platinum-carbon catalysts.
• To investigate the impact of electronic metal-support interactions on reaction pathways and intermediates.
• To develop a predictive strategy for enhancing catalytic performance based on interfacial properties.

Main Methods:

• In situ spectroscopic and kinetic analyses.
• Multi-scale simulations, including molecular dynamics with reactive force fields.
• Density functional theory (DFT) calculations.
• Steady-state and transient kinetic analyses.

Main Results:

• A quantitative description of the competition between oxygen association and dissociation mechanisms, modulated by interfacial charge and CO coverage.
• Identification of a shift in the rate-determining step (RDS) from O2* dissociation to O* and CO* or O2* and CO* association.
• Development of a de novo strategy linking interfacial charge distribution to reaction mechanism, RDS kinetics/thermodynamics, and catalytic performance.
• Achieved an order-of-magnitude increase in CO oxidation reactivity.

Conclusions:

• Electronic metal-support interactions play a critical role in tuning CO oxidation mechanisms and kinetics on platinum-carbon catalysts.
• The developed de novo strategy provides a quantitative framework for understanding and optimizing heterogeneous catalysis.
• This work is expected to advance theories and methodologies in the field of heterogeneous catalysis.