Porous Hollow Fiber Nickel Electrodes for Effective Supply and Reduction of Carbon Dioxide to Methane through Microbial Electrosynthesis
Porous Hollow Fiber Nickel Electrodes for Effective Supply and Reduction of Carbon Dioxide to Methane through Microbial Electrosynthesis
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DOI：
10.1002/adfm.201804860
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发表时间：
2018-10-24
影响因子：
19
通讯作者：
Saikaly, Pascal Elias
中科院分区：
文献类型：
--
作者：
Alqahtani, Manal F.;Katuri, Krishna P.;Saikaly, Pascal Elias
微生物电化学将二氧化碳气体还原为高附加值的化工产品需要开发一种具有三相界面的电极结构，以实现有效的质量传输。通过将一种新的电极结构与丰富的产甲烷群落相结合，开发了一种将CO2还原为CH4的混合生物无机体系。这种新颖的电极设计由多孔镍中空纤维组成，它作为质子还原生成氢气的无机电催化剂，并作为气体传输膜，通过中空纤维的孔道将二氧化碳直接输送到阴极上固定二氧化碳的生氢甲烷菌(生物催化剂)。电极的这些独特功能为甲烷菌的浓缩创造了合适的环境，甲烷菌利用氢作为二氧化碳转化为CH4的还原当量的来源。镍电极的性能在微生物电合成电池中进行了测试，其阴极电位为-1V，而对Ag/AgCl的阴极电位为-1V，对甲烷的法拉第效率高达77%。复合生物无机体系的优异性能归功于电极结构，它为气液反应提供了一个三相边界，反应由无机和生物催化剂支持。
Microbial electrochemical reduction of CO2 gas to value-added chemical products requires the development of an electrode architecture with a three-phase interface for efficient mass transport. A hybrid bioinorganic system for CO2 reduction to CH4 is developed by coupling a new electrode architecture with enriched methanogenic community. The novel electrode design consists of porous nickel hollow fibers, which act as an inorganic electrocatalyst for hydrogen generation from proton reduction and as a gas-transfer membrane for direct CO2 delivery to CO2-fixing hydrogenotrophic methanogens (biological catalyst) on the cathode through the pores of the hollow fibers. These unique features of the electrode create a suitable environment for the enrichment of methanogens, which utilize the hydrogen as a source of reducing equivalents for the conversion of CO2 to CH4. The performance of the nickel electrode is tested in microbial electrosynthesis cells operated at cathode potential of -1 V versus Ag/AgCl, achieving high faradaic efficiency of 77% for CH4. The superior performance of the hybrid bioinorganic system is attributed to the electrode architecture, which provides a three-phase boundary for gas-liquid reactions, with the reactions supported by the inorganic and biological catalysts.