Dr. Lili Lu, Lead Research Scientist, Corporate Technology, Siemens Shanghai Center, China.

Speech Title: CO₂ to Value: Single Step Direct Electrocatalytic Reduction of CO₂ Toward CO and Hydrocarbons

Abstract: Storage or conversion possibilities are essential for large overcapacities of renewable power generation from solar and wind, due to their intermittency and the volatility of electricity. However, economic feasibility is difficult when considering the physical efficiency limitations of the processes and the low prices of the fossil fuels. Electrochemical conversion of CO₂ powered by renewable energies is one of the strategies. Therefore, we focus on the conversion product of the chemical feedstock such as ethylene or CO, where the chemical value exceeds by far its pure heating value. For improvement of the product selectivity, substantial advances in electrode design are required. In our work, CO could be obtained with faradic efficiencies over 90% at current densities exceeding the industrial necessary level of 100-300 mA/cm^² with a total energy efficiency approaching 50%. Ethylene is more challenging due to the highly complex reduction process. Faradic efficiencies up to 57% for ethylene at current densities above 150 mA/cm^² could be obtained. In many experiments we also observed formation of liquid products of ethanol, C1-C₃ alcohols, carboxylates, and ketones. To the best of our knowledge, the here reported faradaic efficiencies for ethanol above 20% at current densities above 150mA/cm² are among the highest values so far reported in the literatures.