The formation of carbonate and the associated energy losses are one of the main challenges for the economically viable reduction of CO2. It is well-known that the kinetics and thermodynamics of the formation of carbonate as well as the electrocatalytic reduction of CO2 itself are highly pH sensitive. Measuring the interfacial pH at the electrode is not trivial due to convoluting effects of mass transport and the consumption of protons due to CO2 reduction concomitant with parasitic hydrogen evolution. Most previously reported approaches offer insights only to a limited extent or on model catalysts. Here, we report the use of transient kinetic measurements with isotopically labeled CO2 by Differential Electrochemical Mass Spectrometry on various gas diffusion electrodes. By both measuring the steady state absorption of CO2 into the electrolyte in the microporous layer as well as the transient decay curve, we are able to determine the rates of carbonate formation as well as interfacial pH swings.

Transient kinetic isotope effects reveal interfacial CO2 dissolution kinetics

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.