(569fh) Breaking Frontiers in Selective Electroreduction of CO2 to Ethylene Under Controlled Catalyst Regeneration

Electrochemical reduction of CO₂ (ECR) powered by renewable energy sources have emerged as a powerful technology to fight a global battle against climate change. Considering the huge industrial importance of products such as ethylene and ethanol, it is necessary to find sustainable methods for synthesizing these products. This work focus on breaking frontiers in finding new avenues for tailoring the selectivity towards products from electrochemical reduction of CO₂ along-with high current density and long-term stability. In comparison to bare Cu metal as catalyst, the presence of copper oxides (Cu₂O) has shown higher selectivity towards products. Therefore, copper oxides (Cu₂O) is used as catalyst. Further, a methodology is employed for catalyst regeneration under controlled microenvironments by applying asymmetric reduction and oxidation pulses. The experimental results reveal that 50% FE for C2 products is attained by optimizing the parameters such as oxidation potential , reduction potential , reduction time and oxidation time. Once the catalyst regeneration is ensured, the electrolyzer design is further optimized to attain higher selectivity towards C2 products. The factors under consideration are 1) Flow configuration; (2) Catalyst location; (3) Improve hydrodynamics for bubble clearance; (4) Process parameters and (5) the strategy to attain target potential. The fluid travels across the catalyst in cross flow configuration. Whereas, the fluid travels along the mesh in flow-by configuration. The results shows that C1 products (methane and formic acid) is dominating (60% FE) in cross flow configuration. On the other hand, C2 products (ethylene and ethanol) with FE 50% dominates in flow by configuration. Further, a relationship between higher selectivity towards products in presence of Cu(I) oxides is established. In addition to promoting C-C bond formation, the dynamic regeneration of oxides prevents higher alkalinity near the catalyst interface. This study opens new pathways for attaining higher selectivity towards products.