ECS Webinar: “Challenges in CO2 Reduction Selectivity Measurements by Hydrodynamic Methods”

Maria Kelly

Maria Kelly
Sandia National Laboratories

Date: March 18, 2026
Time: 1300-1400h ET

(Click to enlarge)

The electrochemical CO₂ reduction converts CO₂ to higher value products using an electrocatalyst and could pave the way for electrification of the chemical industry. A key challenge for CO₂ reduction is its poor selectivity (i.e., faradaic efficiency) due to competition with the hydrogen evolution reaction in aqueous electrolytes. Rotating ring disk electrode (RRDE) experiments have emerged as a popular method to quantify faradaic efficiencies, especially for gold electrocatalysts. However, such measurements suffer from poor inter-laboratory reproducibility. This work identifies the causes of variability in RRDE selectivity measurements by comparing protocols with different electrochemical methods, reagent purities, and glassware cleaning procedures. Electroplating of electrolyte impurities onto the disk and ring surfaces were identifies as major contributors to electrocatalyst deactivation. These results highlight the need for standardized and cross-laboratory validation of CO₂RR selectivity measurements by RRDE. Researchers implementing this RRDE technique for CO₂RR selectivity measurements need to be cognizant of electrode deactivation and its potential impacts on FEs and overall conclusions of their work.

Why attend this webinar:

Learn about:

• The electrochemical CO2 reduction reaction
• Benefits and challenges of rotating ring disk electrode measurements for reaction selectivity quantification
• The influence of electrolyte impurities on electrochemical reactions

Presenter

Maria Kelly is currently a Jill Hruby Postdoctoral Fellow at Sandia National Laboratories. She completed her PhD in Prof. Wilson Smith’s research group at the University of Colorado Boulder and the National Renewable Energy Laboratory. Her PhD focused on the  characterization of carbon dioxide conversion interfaces using analytical electrochemical and in situ scanning probe methods. Her research interests broadly encompass advancing experimental measurement techniques to investigate the near-electrode environment during electrochemical reactions.

Thanks to the webinar sponsors who make these complimentary programs possible!

Interested in presenting in the ECS Webinar Series? Email your presentation title and abstract to education@electrochem.org for consideration.