Harnessing renewable electricity to drive the electrochemical reduction of CO2 is being intensely studied for sustainable fuel production and as a means for energy storage. Copper is the only monometallic electrocatalyst capable of converting CO2 to value-added hydrocarbons and oxygenates, but suffers from poor selectivity and mediocre activity. Multiple oxidative treatments have shown improvements in the performance of copper catalysts. However, the fundamental underpinning for such enhancement remains controversial. Oxygen containing species induced from oxidative treatments could be the origin of the enhanced reactivity, while the role of oxygen-containing species on Cu catalysts in the electrochemical CO2 reduction reaction (CO2RR) remains unclear due to the difficulty in its characterization and stabilization at reaction conditions. In this talk, we report a co-electrolysis strategy in which oxidants (i.e., O2, H2O2) are reduced along with CO2 on Cu catalysts as an effective strategy to introduce stable oxygen-containing species on Cu surface during the CO2RR. We investigate the presence and role of oxygen-containing species in CO2RR at co-electrolysis via a combination of reaction design, surface enhance in situ Raman spectroscopy and computation based on density functional theory. Our results demonstrate that oxygen-containing species is able to enhance the rate of the CO2RR, and the selectivity of product formation can also be tuned by different oxygen-containing species generated by different oxidants. Our results highlight the importance of oxygen-containing species in promoting catalytic performance of Cu-based materials in CO2RR.

Oxidant induced promotion of CO2 electroreduction on Cu via co-electrolysis

ACS Spring 2022

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