Nonequilibrium thermodynamics--A tool to describe heterogeneous catalysis

Area of Science:

• Chemical Engineering
• Physical Chemistry
• Thermodynamics

Background:

• Traditional film models for mass transfer neglect heat-mass coupling and surface phenomena.
• Assumptions of continuous temperature and chemical potentials at catalytic surfaces are often questionable.
• Negligible coupling between heat flux and mass fluxes limits accuracy in heterogeneous catalysis studies.

Purpose of the Study:

• To integrate the coupling between heat and mass fluxes within the film model using non-equilibrium thermodynamics.
• To introduce the surface as a distinct thermodynamic system allowing for heat-mass coupling in heterogeneous catalysis.
• To develop a consistent and complete description of mass and heat transfer from the film to the reactive surface.

Main Methods:

• Application of non-equilibrium thermodynamics to describe coupled heat and mass transfer.
• Incorporation of Gibbs' surface thermodynamics to model surface phenomena.
• Development of rate equations based on surface thermodynamic theory.

Main Results:

• A framework is established for describing coupled heat and mass transfer in heterogeneous catalysis.
• The significance of heat-mass coupling at the catalyst surface is highlighted.
• Non-equilibrium thermodynamics provides accurate predictions of surface temperature and system behavior.

Conclusions:

• Non-equilibrium thermodynamics offers a robust approach to model coupled heat and mass transfer in catalytic systems.
• Accounting for surface phenomena and temperature gradients is crucial for accurate catalyst characterization.
• The developed model provides a unified description of the film and surface for effective surface analysis.