(73i) A Quantum Theoretical Development of Platinum-Ruthenium-Tin Anodic Catalysts for Enhanced Direct Ethanol Fuel Cell Performance

In pursuit of
clean and renewable energy, fuel cell technology studies aim to combat growing
global energy concerns.  The design of
anodic catalysts for direct ethanol proton exchange membrane fuel cells has
been a particular focus to offer goals of enriched efficiency, longevity, and
cost.  Computational efforts in surface
chemistry allow for a semi-quantitative description of reaction processes to be
developed that will aid in meeting said objectives.  Presently, the assessment of metal alloying
effects on the activity of Pt-based nanostructures for the electro-oxidation of
ethanol appears promising.  This study
employs the DMol³ suite of the Materials Studio 6.0 software to
conduct First-Principles, Density Functional Theory and Transition State Theory,
calculations as a theory-driven approach to outlining equilibrium Pt-Ru-Sn
(2:2:1) nanostructures and exploring the ethanol oxidation reaction (EOR)
mechanism across the catalyst surface.  A
systematic optimization is performed on two candidate configurations with functionals of Local-Density Approximation and Generalized-Gradient
Approximation exchanges accompanied by varied correlation combinations.  Lastly, an exploration of EOR transition
states is carried out using a complete Linear Synchronous Transit/Quadratic
Synchronous Transit method, prefaced by a similar optimization procedure on
species-catalyst complexes. Results shown include energy profiles, itemized by:
(1) Cohesive Energy, E_c, of 10-atom structure
and (2) Activation Energy, E_a, for EOR
across metal surface.  This information
provides a framework for understanding important kinetics and thermodynamic
details that could lead to the development of novel catalysts for energy
applications.