Work

Operando spectroelectrochemical identification of peroxide intermediate in molten carbonate CO2-to-carbon electroreduction

Year: 2026

Type: article

Abstract: Electrolysis of CO 2 in molten salts promises efficient carbon capture, but the underlying reaction mechanisms remain incompletely understood, as research thus far has been limited by a lack of tools for operando investigations. Here, we use a high-temperature operando Raman spectroelectrochemical system to look for signatures of reaction intermediates and study the evolution of carbon structures over electrolysis time. The analysis reveals the existence of O 2 2− concurrently with the deposition of carbon on Au, W, Inconel, and Ni electrode materials, pointing to a common reaction mechanism with O 2 2− as an intermediate. Secondly, the G peak of the as-deposited carbon experiences a noticeable blue-shift as the material is cooled down and purified, suggesting either a growth in crystallite size even after the electrolysis is stopped or lithium deintercalation. Elucidating the cathodic carbon deposition mechanism could help create greater value-added products and increase the economic viability of carbon capture.

Source: Nature Communications

DOI: 10.1038/s41467-026-70977-0

Authors: Sander Ratso, Michael L. Whittaker, Kätlin Kaare, Raluca O. Scarlat

Institutions: National Institute of Chemical Physics and Biophysics, University of California, Berkeley, Lawrence Berkeley National Laboratory

Language: English

Topic: CO2 Reduction Techniques and Catalysts

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Climate action, Affordable and clean energy

Open Access status: gold

Estimated APC paid: $6,990