title: Nanoalloy electrocatalysis: simulating cyclic voltammetry from configurational thermodynamics with adsorbates.
abstract: We simulate the adsorption isotherms for alloyed nanoparticles (nanoalloys) with adsorbates to determine cyclic voltammetry (CV) during electrocatalysis. The effect of alloying on nanoparticle adsorption isotherms is provided by a hybrid-ensemble Monte Carlo simulation that uses the cluster expansion method extended to non-exchangeable coupled lattices for nanoalloys with adsorbates. Exemplified here for the hydrogen evolution reaction, a 2-dimensional CV is mapped for Pd-Pt nanoalloys as a function of both electrochemical potential and the global Pt composition, and shows a highly non-linear alloying effect on CV. Detailed features in CV arise from the interplay among the H-adsorption in multiple sites that is closely correlated with alloy configurations, which are in turn affected by the H-coverage. The origins of specific features in CV curves are assigned. The method provides a more complete means to design nanoalloys for electrocatalysis.
authors.affiliation: Ames Laboratory, U.S. Department of Energy at Iowa State University, Ames, IA 50011, USA. llw@ameslab.gov ddj@ameslab.gov.
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Wang
authors.forename: Teck L
authors.initials: TL
authors.lastname: Tan
authors.forename: Duane D
authors.initials: DD
authors.lastname: Johnson