Oxides and Carbonates Accelerate Copper Instability in CO2 Electroreduction

TL;DR

This study shows that copper catalysts used for converting CO2 into useful products become unstable faster when they have oxides or carbonates on their surface.

Contribution

The paper reveals that oxides and carbonates on copper surfaces accelerate structural instability and reduce CO2 reduction efficiency.

Findings

Copper catalysts with higher initial oxide content reconstruct faster and deactivate more quickly.

Carbonates worsen structural instability and suppress CO2RR activity.

Oxides and carbonates strongly influence the durability and performance of copper catalysts.

Abstract

The electrochemical CO2 reduction reaction
(CO2RR) is one of the key chemical transformations promoting
the transition
from fossil fuel-based energy systems to renewable systems. Copper
(Cu)-based materials uniquely catalyze the production of multicarbon
(C2
+) products from CO2. Yet, copper
operational instability limits long-term performance. Herein, we investigate
the impact of the chemical nature of the initial Cu surface, particularly
oxidation state and carbonate formation, on the structural and operational
stability of Cu catalysts along with the reconstruction kinetics of
the catalyst. We combine state-of-the-art well-defined catalysts with
quasi-operando electrochemical liquid-phase transmission electron
microscopy (ec-LPTEM) along with electrochemical characterization
to learn about underlying differences. We demonstrate that catalysts
with higher initial oxide content undergo faster structural reconstruction
and suffer from faster operational deactivation. Interestingly, we
find that Cu carbonates further exacerbate structural instability
while also suppressing the CO2RR activity. Our results
highlight the critical role of oxides and carbonates in dictating
the reconstruction pathways and durability of Cu under CO2RR conditions, offering insights into tuning the Cu-based catalyst
design for enhanced CO2RR stability and efficiency.

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