464406 NO Electrochemical Reduction on Pt(100) from First Principles
While Pt(111) terraces are the lowest in energy of any single crystal Pt surface, terraces of Pt(100) have shown unusual activity and selectivity patterns for the electroreduction of NO. Therefore, in this work, we use periodic, self-consistent DFT calculations to clarify the adsorption structures and energetics of NO and its reaction intermediate species on the Pt(100) surface. Solvation energies and protonation kinetics are calculated using water-incorporated systems in the DFT analysis.In addition, we implement a rigorous kinetic Monte Carlo (kMC) approach that takes into account coverage-dependent interactions and activation barriers and that as that produces potential-dependent values of current from multiple reaction pathways as a function of voltage.
In our simulation, the most favorable pathway is the ammonia formation. The mechanism consists of two consecutive proton-electron transfer steps after the adsorption of NO (denoted the EE mechanism), with favorable formation of NOH* as a first intermediate. The Tafel slope, which was obtained by plotting peak potentials at different scan rates in kMC simulations, supports the EE mechanism rather than the chemical dissociation steps. Also, due to the fast protonation, the probabilities of forming N2 or N2O are negligible. Finally, implications of these results for both NO and nitrate electroreduction on other transition metal surfaces will be discussed.
 M. Duca and M. T. M. Koper, Energ. Environ. Sci. 5 (2012) 9726.
 A. Cuesta, M. Escudero, Phys. Chem. Chem. Phys. 10 (2008) 3628.
 V. Rosca, M. T. M. Koper, J. Phys. Chem. B 109 (2005) 16750.
 A. Clayborne, H. J. Chun, R. B. Rankin, J. Greeley, Angew. Chem. Int. Ed. 54 (2015) 8255.
See more of this Group/Topical: Catalysis and Reaction Engineering Division