创新背景

二氧化碳转化途径众多，历史最悠久且最常见的就是自然界的光合作用。光合作用对二氧化碳的转化至关重要，但其也存在效率低下的问题。利用已知的原料辅以科技手段促进二氧化碳转化为有效能源，将促进环境科学和能源发展。

创新过程

美国国家可再生能源实验室和迈阿密大学的联合研究小组在能源转化问题上开发出二氧化碳新的转化方式，在改造蓝藻的基础上利用电力，可以将二氧化碳转化为乙烯或醋酸，使生物电化学杂化物具有生产燃料化学品的潜力。2021年，相关研究成果《流经蓝藻光系统I的外源性电流驱动CO2高能效的增值》发表在《能源与环境科学》杂志上。

研究人员将将自然界的光合作用分为光系统I和光系统II两个主要系统。光系统I利用光作用保证电子可以跨膜转移；光系统II中酶捕捉光子，反作用于电子使其获得能量。自然界的光合作用过程中，光系统吸收光谱有重叠部分，光系统II产生的氧气不可避免地要与二氧化碳竞争酶来固定碳途径，且对光的利用仅限于太阳光谱中的部分有限光。一系列条件限制导致自然光合作用转化二氧化碳效率低下。

研究转化二氧化碳实在改造光合作用过程和蓝藻的基础上进行的。先将能进行产氧性光合作用的大型单细胞原核生物蓝藻进行改造，使它能利用太阳光和电子流驱动固定二氧化碳，以人工系统取代光系统II。人工生成的系统将修改后的蓝藻连接到一个电路上，电子将进入活蓝藻中的PETC。阴极电化学与蓝藻细胞接口，通过照明使蓝藻暴露在光线下，输送电子给光系统I，最终促进蓝藻将二氧化碳转化为醋酸盐。在提供照明和外源电子时，作用过程会进一步形成乙酸盐。

新方法适用于转化二氧化碳进行能源替换，所使用的蓝藻之一使乙烯的电光照相生产成为可能。研究人员表示，该方法可以作为一种能源储存手段，促进温室气体转化为环保燃料，推动能源利用和环境科学双向发展。

创新关键点

创新改造蓝藻和光合作用系统提高二氧化碳转化效率。

Modify cyanobacteria to improve carbon dioxide conversion efficiency

A joint research team from the National Renewable Energy Laboratory and the University of Miami has developed a new way of converting carbon dioxide on the issue of energy conversion, using electricity on the basis of transforming cyanobacteria, which can convert carbon dioxide into ethylene or acetic acid, giving bioelectrochemical hybrids the potential to produce fuel chemicals. In 2021, the research results "Exogenous electricity flowing through cyanobacterial photosystem I drives CO2 valorization with high energy efficiency" were published in the journal Energy and Environmental Science.
The researchers will divide photosynthesis in nature into two main systems, photosystem I and photosystem II. Optical system I uses light action to ensure that electrons can be transferred across membranes; Enzymes in Photosystem II capture photons and reactively on electrons to obtain energy. In the process of photosynthesis in nature, the absorption spectrum of the photosystem has overlapping parts, and the oxygen produced by the photosystem II inevitably competes with carbon dioxide enzymes to fix the carbon pathway, and the use of light is limited to the limited light in the part of the solar spectrum. A series of conditional constraints lead to inefficient conversion of carbon dioxide from natural photosynthesis.
Studies of converted carbon dioxide are carried out on the basis of transforming the photosynthetic process and cyanobacteria. The large single-cell prokaryote cyanobacteria capable of oxygen-producing photosynthesis was first modified so that it could use sunlight and electron streams to drive fixed carbon dioxide, replacing photosystem II with an artificial system. The artificially generated system connects the modified cyanobacteria to a circuit where electrons will enter the PETC in the live cyanobacteria. Cathodic electrochemistry interfaces with cyanobacterial cells, exposes cyanobacteria to light through illumination, delivers electrons to light system I, and ultimately promotes cyanobacteria to convert carbon dioxide into acetate. When illumination and exogenous electrons are provided, the process of action further forms acetates.
The new method is suitable for converting carbon dioxide for energy replacement, and one of the cyanobacteria used makes the electro-photopic production of ethylene possible. The researchers said that the method can be used as a means of energy storage, promote the conversion of greenhouse gases into environmentally friendly fuels, and promote the two-way development of energy utilization and environmental science.