(294d) Design Rules for Ultrathin Permeable Coatings Deposited on Electrocatalytic Thin Films

Encapsulating electrocatalysts or photocatalysts with ultrathin permeable overlayers offers additional “control knobs” for tuning electrocatalyst selectivity and/or activity in ways that are not possible with conventional electrocatalysts.[1] For example, overlayers can leverage selective transport characteristics to protect the underlying catalyst from impurities while significantly altering the concentrations of reactants and intermediates the electrocatalytic buried interface.[2] In this presentation, I will describe general design principles for engineering permeable electrocatalyst overlayers, with an emphasis on understanding how the thickness and transport properties of overlayers impacts limiting current densities and concentration overpotentials. Of particular interest is determining the minimum overlayer thickness that will allow for targeted stability and/or selectivity enhancements while still allowing for the required fluxes of reactant species as required for the application of interest. The analysis and methodologies presented in this talk are primarily based on modeling and experimental investigations of model silicon oxide (SiOx)-encapsulated platinum (Pt) thin film electrocatalysts, but may be extended to many other combinations of overlayer and (photo)electrocatalyst materials for a wide range of electrochemical reactions.

References

[1] D.V. Esposito, ACS Catalysis, 2018, vol. 8, pp 457–465.

[2] N. Y. Labrador, E. L. Songcuan, C. De Silva, Han Chen, Sophia Kurdziel, Ranjith K. Ramachandran, Christophe Detavernier, D.V. Esposito, ACS Catalysis, vol. 8, 1767–1778, 2018.