Abstract:

Electrocatalysis offers a pathway to reduce greenhouse gas emissions in the energy and chemical industries by storing or converting renewable electrons into value-added fuels and chemicals. Efforts to develop non-precious metal electrocatalysts for low temperature oxygen reduction (ORR) and oxygen evolution (OER) reactions—key efficiency bottlenecks in hydrogen generation and use—are increasingly looking towards materials that display bulk ion insertion functionality. In emerging electrocatalytic material classes including perovskite oxides, transition metal (oxy)(hydr)oxides, and organic semiconducting polymers, the activity and stability of the surface is found to be coupled to the reactivity of the bulk through voltage-dependent compositional changes driven by electrochemical ion insertion. The catalytic state is thus inherently far from equilibrium, complicating its direct observation and challenging our efforts to design materials based on static ex-situ derived properties.

In this talk, I will provide an overview of the experimental and computational approaches to understand the influence of ion insertion on reactivity in these emerging electrocatalytic systems. The connection between surface and bulk reactivity is characterized through a multi-modal approach integrating electroanalytical techniques and operando X-ray, vibrational, and scanning probe microscopies. The experimental results inform first principles calculations and microkinetic models used to decipher reaction mechanisms and simulate the observed electrochemical behavior. Through this approach, I show how ion insertion can be leveraged to develop new pathways for reactivity and catalyst design for the electrification of chemical production.