Real-time Monitoring Reveals Dissolution/Redeposition Mechanism in Copper Nanocatalysts during the Initial Stages of the CO_2 Reduction Reaction

摘要

With global pressure to find ways to reduce CO_2 emissions, the electrochemical CO_2 reduction reaction poses a promising way forward. Understanding how electrocatalysts change in terms of their morphology, size and surface composition is an effective approach to their rational design, with the goal to improve their stability while retaining activity and selectivity. With the aid of transmission electron microscopy and operando X-ray spectros-copy, the reconstruction of copper-based nanocatalysts during the start-up phase of the CO_2 reduction reaction, was investigated. Results revealed that dissolution and redeposition, rather than coalescence, is the mechanism responsible for the change in morphology of the electrocatalyst. In addition, the formation of copper oxides was found to play key a role in the process.