A Multisite Microkinetic Framework for Describing Interfacial Kinetics in Dry Methane Reforming (DRM) over Ni-CeO₂...

Area of Science:

• Catalysis
• Chemical Engineering
• Materials Science

Background:

• Oxide-supported Ni catalysts are crucial for dry reforming of methane (DRM).
• The metal-support interface is key for O-transport and H-spillover in DRM.
• Understanding interfacial processes is vital for optimizing DRM catalysts.

Purpose of the Study:

• To develop a multisite microkinetic model for the Ni-CeO2 system.
• To elucidate the role of interfacial processes in DRM activity and selectivity.
• To investigate how Ni nanoparticle size affects reaction kinetics and deactivation.

Main Methods:

• Developed a multisite microkinetic model for Ni-CeO2.
• Utilized density functional theory (DFT) for kinetic parameters.
• Performed global sensitivity analysis (Sobol) and degree of rate control (DRC) analysis.

Main Results:

• Model shows mixed dependencies of DRM rate on CH4 and CO2 pressures.
• Ni nanoparticle radius (rm) is a dominant geometric parameter.
• CH4 activation is rate-limiting for small Ni nanoparticles; O-transport limits larger ones.

Conclusions:

• The model captures the transition to deactivation-prone regimes without explicit coking pathways.
• This work provides a mechanistic framework for studying interface-mediated reactions.
• The model serves as a predictive tool for designing efficient DRM catalysts.