Bioelectrosynthetic Conversion of CO2 Using Different Redox Mediators: Electron and Carbon Balances in a Bioelectrochemical System

Energies

Chulhwan Park¹  Booki Min²  Shuwei Li³  Minsoo Kim³  Mutyala Sakuntala³  JungRae Kim³  Jiyun Baek³  YoungEun Song³  HyeonSung Im³ 

[1] Department of Chemical Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Korea;Department of Environmental Science and Engineering, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi-do 446-701, Korea;School of Chemical and Biomolecular Engineering, Pusan National University, Busan 46241, Korea;

关键词: carbon dioxide;    microbial electrosynthesis (MES);    redox mediator;    carbon and electron balance;   

DOI  :  10.3390/en13102572

来源: DOAJ

【 摘 要 】

Microbial electrosynthesis (MES) systems can convert CO₂ to acetate and other value-added chemicals using electricity as the reducing power. Several electrochemically active redox mediators can enhance interfacial electron transport between bacteria and the electrode in MES systems. In this study, different redox mediators, such as neutral red (NR), 2-hydroxy-1,4-naphthoquinone (HNQ), and hydroquinone (HQ), were compared to facilitate an MES-based CO₂ reduction reaction on the cathode. The mediators, NR and HNQ, improved acetate production from CO₂ (165 mM and 161 mM, respectively) compared to the control (without a mediator = 149 mM), whereas HQ showed lower acetate production (115 mM). On the other hand, when mediators were used, the electron and carbon recovery efficiency decreased because of the presence of bioelectrochemical reduction pathways other than acetate production. Cyclic voltammetry of an MES with such mediators revealed CO₂ reduction to acetate on the cathode surface. These results suggest that the addition of mediators to MES can improve CO₂ conversion to acetate with further optimization in an operating strategy of electrosynthesis processes.

【 授权许可】

Unknown