Electrosynthesis of Six-Carbon Acetal from CO<sub>2</sub> Using a Tandem Electrolysis
Haoyuan Chi, Zhanpeng Liang, Siyu Kuang, Yaxin Jin, Tian‐Tian Xiao, Jianlong Lin, Dejun Han, Lei Wang, Sheng Zhang, Xinbin Ma
Abstract
The conversion of CO 2 into high-value chemicals using renewable electricity offers a promising pathway toward carbon neutrality and sustainable chemical production. However, efficiently transforming CO 2 into molecules with more than three carbon atoms remains a major challenge. Herein, we propose, for the first time, a tandem electrocatalytic strategy for converting CO 2 into the highly valuable six-carbon compound 1,1-diethoxyethane (DEE, valued at ∼$7,000 per ton). This approach couples CO 2 electroreduction to ethanol with the subsequent selective electro-oxidation of ethanol to DEE. Key limitations of the latter step, such as low Faradaic efficiency, poor catalyst durability, and dependence on noble metals, are addressed by employing a large-area (100 cm 2 ) electrochemically functionalized graphite flake electrode. This catalyst achieves high FE (>90% across a wide voltage range) and excellent stability (>140 h). Combined theoretical and experimental studies reveal that the COOH functional groups and carbon defects on the graphite synergistically modulate the adsorption of the key CH 3 CH 2 O* intermediate, reducing the energy barrier of the rate-determining step. Techno-economic and carbon footprint analyses further demonstrate the economic viability and carbon reduction potential of this tandem process, with an estimated net removal of ∼370 kg of CO 2 per ton of DEE produced.