Physics and Chemistry of Electrified Interfaces

“pH effects” in electrocatalysis

Professor Karen Chan, Technical University of Denmark

Beyond surface reaction energetics, the structure and composition of the electric double layer exerts an influence on the activity and selectivity of electrochemical reactions. These phenomena often manifest themselves as so-called “pH effects”, which manifest as deviations in the dependence of activity from a potential vs. RHE scale.  In this talk, I first discuss the impact of the electrolyte on electrocatalytic activity from the perspective of the impact of the proton donor and adsorbate dipole-field interactions, as well as how cations and supported single site catalysts tune the latter. I then discuss the impact of solution phase reactions and mass transport on activity and selectivity. I draw examples from hydrogen evolution and electrochemical CO₂ reduction, and discuss the implications of fundamental mechanistic understanding on catalyst design.

Water metal interfaces by ab initio molecular dynamics

Dr Marcella Iannuzzi, University of Zurich, Switzerland

Condensed aqueous systems serve an important role in many scientific fields such as materials science, electrochemistry and nanotechnology. Many important reactions occur in aqueous phases or at aqueous solid interfaces. Understanding these processes may provide useful insights on improving the reactivity for electrodes and having better control of the electro-chemical reactions. The microscopic picture of the electrochemical interface is currently investigated by means of several spectroscopies, like IR and Raman, but also using X-ray probes. The goal is to reveal important aspects like the hydrogen bonding network, the distribution of ions, coverages and
adsorption species and sites. With the help of ab initio molecular dynamics (AIMD) simulations at the density functional level of theory, we characterize the water-metal interfaces under different conditions. In particular we investigate chemisorbed water at different metal surfaces, like Pt, Au, and Pd, showing the effects of the electronic redistribution. Other chemisorbed species and ions compete with the adsorption of water and play also a role in determining the properties of the
interface. We show that AIMD simulations provide fundamental insight and understanding on microscopic structures and processes at interfaces

Structure and dynamics of ionic liquids confined between metallic surfaces

Professor Marialore Sulpizi, Johannes Gutenberg University Mainz, Germany.

Abstract to follow

Dr Mira Todorova, Max-Planck Institut, Germany

Title and abstract to follow