(427a) Descriptors for Anion Adsorption Energetics on Metal Electrodes

Anion specific adsorption to a metal (electrode) surface is an important phenomenon in electrochemistry and catalysis. Anions present in an electrolyte can specifically adsorb during fuel cell operation, blocking active sites and reducing the rate of electrocatalytic reactions proportional to their coverage on the surface.^1,2 Anions may specifically adsorb and leave only specific site geometries available on the surface, altering catalytic reaction mechanisms and subsequently reaction activity and selectivity.^3,4 Anions may also participate directly in an electrocatalytic reaction as reactants, such as for nitrate reduction, and their adsorption strength to the surface may dictate the rate of the reaction.^5,6 In our recent work, we have used a combination of density functional theory (DFT) modeling and detailed experiments on single crystal electrodes to identify molecular descriptors that predict anion adsorption energetics onto metal surfaces. These descriptors will allow us to approximate the adsorption energy of any anionic species, without needing to perform additional experiments or DFT simulations. Further, we have used these descriptors to better understand the chemistry of anion adsorption and are working to now build a general, phenomenological model of adsorption (of any species) in the electrochemical environment.

1. A. Attard, A. Brew, K. Hunter, J. Sharman, E. Wright; Phys. Chem. Chem. Phys., 16, 13689 (2014).
2. M. Markovic, H.A. Gastieger, B.N. Grgur, P.N. Ross; J. Electroanal. Chem., 467, 157-163 (1999).
3. Cuesta, M. Escudero, B. Lanova, H. Baltruschat; Langmuir, 25, 6500-6507 (2009).
4. Chen, L.P. Granda-Marulanda, I.T. McCrum, M. Koper; Nature Communications, 13:38, 1-11 (2022).
5. -X. Liu, D. Richards, N. Singh, B.R. Goldsmith; ACS Catal., 9, 7052-7064 (2019).
6. -E. Bae, K.L. Stewart, A.A. Gewirth; J. Am. Chem. Soc., 129, 10171-10180 (2007).