Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Altenberger Strasse 69, 4040, Linz, Austria.
The Austrian Centre of Industrial Biotechnology (acib GmbH), Stahlstrasse 14, 4020, Linz, Austria.
Chembiochem. 2019 May 2;20(9):1196-1205. doi: 10.1002/cbic.201800784. Epub 2019 Mar 12.
Microbial electrosynthetic cells containing Methylobacterium extorquens were studied for the reduction of CO to formate by direct electron injection and redox mediator-assisted approaches, with CO as the sole carbon source. The formation of a biofilm on a carbon felt (CF) electrode was achieved while applying a constant potential of -0.75 V versus Ag/AgCl under CO -saturated conditions. During the biofilm growth period, continuous H evolution was observed. The long-term performance for CO reduction of the biofilm with and without neutral red as a redox mediator was studied by an applied potential of -0.75 V versus Ag/AgCl. The neutral red was introduced into the systems in two different ways: homogeneous (dissolved in solution) and heterogeneous (electropolymerized onto the working electrode). The heterogeneous approach was investigated in the microbial system, for the first time, where the CF working electrode was coated with poly(neutral red) by the oxidative electropolymerization thereof. The formation of poly(neutral red) was characterized by spectroscopic techniques. During long-term electrolysis up to 17 weeks, the formation of formate was observed continuously with an average Faradaic efficiency of 4 %. With the contribution of neutral red, higher formate accumulation was observed. Moreover, the microbial electrosynthetic cell was characterized by means of electrochemical impedance spectroscopy to obtain more information on the CO reduction mechanism.
研究了含有甲基杆菌的微生物电合成电池，通过直接电子注入和氧化还原介体辅助的方法将 CO 还原为甲酸盐，以 CO 作为唯一的碳源。在 CO 饱和条件下，施加-0.75 V 相对于 Ag/AgCl 的恒定电位，在碳纤维毡 (CF) 电极上形成生物膜。在生物膜生长期间，连续观察到 H 2 的析出。通过施加-0.75 V 相对于 Ag/AgCl 的电位研究了含有和不含有中性红作为氧化还原介体的生物膜对 CO 还原的长期性能。中性红以两种不同的方式引入系统：均相（溶解在溶液中）和异相（电聚合到工作电极上）。首次在微生物系统中研究了异相方法，其中 CF 工作电极通过其氧化电聚合被涂覆有聚（中性红）。通过光谱技术对聚（中性红）的形成进行了表征。在长达 17 周的长期电解过程中，连续观察到甲酸盐的形成，平均法拉第效率为 4%。在中性红的作用下，观察到更高的甲酸盐积累。此外，通过电化学阻抗谱对微生物电合成电池进行了表征，以获取有关 CO 还原机制的更多信息。
