Exploring the influence of cell configurations on Cu catalyst reconstruction during CO₂ electroreduction

Membrane electrode assembly (MEA) cells incorporating Cu catalysts are effective for generating C₂₊ chemicals via the CO₂ reduction reaction (CO₂RR). However, the impact of MEA configuration on the inevitable reconstruction of Cu catalysts during CO₂RR remains underexplored, despite its considerable potential to affect CO₂RR efficacy. Herein, we demonstrate that MEA cells prompt a unique reconstruction of Cu, in contrast to H-type cells, which subsequently influences CO₂RR outcomes. Utilizing three Cu-based catalysts, specifically engineered with different nanostructures, we identify contrasting selectivity trends in the production of C₂₊ chemicals between H-type and MEA cells. Operando X-ray absorption spectroscopy, alongside ex-situ analyses in both cell types, indicates that MEA cells facilitate the reduction of Cu₂O, resulting in altered Cu surfaces compared to those in H-type cells. Time-resolved CO₂RR studies, supported by Operando analysis, further highlight that significant Cu reconstruction within MEA cells is a primary factor leading to the deactivation of CO₂RR into C₂₊ chemicals.