Abstract
Carbon dioxide (CO2) is currently considered as a waste material due to its negative impact on the environment. However, it is possible to create value from CO2 by capturing and utilizing it as a building block for commodity chemicals. Electrochemical conversion of CO2 has excellent potential for reducing greenhouse gas emissions and reaching zero net emissions by 2050. To date, Carbon Capture and Utilization (CCU) technologies have been studied independently. We report a novel methodology based on the integration of CO2 capture and conversion by the direct utilization of a CO2 capture media as electrolyte for electrochemical CO2 conversion. This has a high potential for reducing capital and operational cost when compared to traditional methodologies. A novel mixture of chemical and physical absorption solvents allowed for the captured CO2 to be converted to formic acid with faradaic efficiencies up to 50 % and with carbon conversion of ca. 30 %. By increasing the temperature in the electrochemical reactor from 20 °C to 75 °C, the productivity towards formic acid increased by a factor of 10, reaching up to 0.7 mmol∙m-2·s-1. The direct conversion of captured CO2 was also demonstrated for carbon monoxide formation with faradaic efficiencies up 45 %.
22. Electrochemical conversion of CO2 into formate or formic acid
