微生物-电极界面生物电催化还原二氧化碳的纳米强化机制

The efficient use of carbon-based energy is a highly strategic demand for our country. Converting carbon dioxide into valuable chemicals via electrochemical reduction reaction has important economic and environmental benefits. Due to the chemical inertness of carbon dioxide molecules, how to improve the electrocatalytic conversion efficiency of the carbon dioxide at room temperature and atmospheric pressure is a key scientific issue. Microbial electrosynthesis is an emerging technology which can convert carbon dioxide at room temperature, atmospheric pressure and neutral pH by using the electrochemically active microorganisms. However, the low electrocatalytic efficiency limits its widespread technological use. This project will study the interfacial reaction mechanism of microbial conversion of carbon dioxide driven by electricity. By coupling with endogenous nanomaterials (nano-palladium or nano-gold) and/or extrinsic nanomaterials (iron nanoparticles or graphene), the interface electron transfer between the microorganisms and the electrode can be enhanced and the efficiency of the electrocatalytic reduction reaction can be improved. By using the in-situ spectroscopic electrochemistry technologies, microelectrode-electrochemical technology, proteomics and chemical analysis methods, the extracellular electron transfer pathways in the process of microbial electrosynthesis will be investigated in-depth. The contributions of the redox proteins and the electron mediators will be revealed. The main limiting factors which effect the biocathode electrosynthesis will be illustrated and the carbon dioxide can be converted to acetic acid efficiently at room temperature and atmospheric pressure. This study will provide theoretical guidance for carbon dioxide resourcialization technologies based on microbial electrosynthesis.

碳基能源的高效利用是我国的重大战略需求。将二氧化碳电化学转化为有价化学品，具有重要的经济与环保效益。由于二氧化碳分子化学惰性强，如何提高其在常温、常压下的电催化转化效率，是实现电能高效转换为化学能的关键科学问题。作为一种新兴技术，微生物电合成可利用电能驱动电活性微生物，在常温、常压、中性pH条件下实现二氧化碳的转化。然而，其较低的电催化效率限制了该技术的广泛应用。本项目针对电驱动微生物转化二氧化碳的界面反应机制进行研究。通过耦合内源性纳米材料（纳米钯、纳米金等）、外源性纳米材料（纳米铁、石墨烯）来强化微生物和电极间的界面电子传递，提高电催化效率；辅助原位光谱电化学法、微电极-电化学联用技术、蛋白组学以及化学分析法，深入研究微生物电合成过程中的胞外电子转移途径，揭示氧化还原蛋白以及电子中介体在反应中的贡献，阐明生物阴极合成反应主要限制因素，为基于微生物电合成的二氧化碳资源化技术提供理论指导。

将二氧化碳转化为有价化学品，具有重要的经济与环保效益。微生物电合成可利用电能驱动功能微生物，在常温、常压、中性pH条件下实现二氧化碳的转化。本项目针对电驱动微生物转化二氧化碳的界面反应机制不清的关键科学问题开展研究，通过原位微生物电化学法、蛋白组学以及液相色谱串联三重四级杆联用分析，深入研究微生物-电极界面反应过程中的胞外电子转移途径，揭示电子中介体以及氧化还原蛋白在反应中的贡献，发现在光照条件下核黄素的光解产物光色素在实际体系中起到了电子中介体的作用；电极电势主要影响沼泽红假单胞菌光收集相关蛋白的运作，外膜和细胞质中的NAD(P)结构域蛋白可以作为光感受器来获取电极电子并主导微生物的氧化磷酸化和光合作用；阐明了生物电极反应主要限制因素，为基于微生物电合成的二氧化碳资源化技术提供理论指导。