Plasma-Modified Dendritic Cu Catalyst for CO₂ Electroreduction

Efficient and active catalysts with high selectivity for hydrocarbons and other valuable chemicals during stable operation are crucial. We have taken advantage of low-pressure oxygen plasmas to modify dendritic Cu catalysts and were able to achieve enhanced selectivity toward C₂ and C₃ products. Utilizing operando spectroscopic methods such as X-ray absorption fine-structure spectroscopy (XAFS) and quasi in situ X-ray photoelectron spectroscopy (XPS), we observed that the initial presence of oxides in these catalysts before the reaction plays an inferior role in determining their catalytic performance as compared to the overall catalyst morphology. This is assigned to the poor stability of the Cu x O species in these materials under the conditions of electrocatalytic conversion of CO₂ (CO₂RR). Our findings shed light into the strong structure/chemical state-selectivity correlation in CO₂RR and open venues for the rational design of more effective catalysts through plasma pretreatments.