(397c) Direct Conversion of Industrial Exhaust Gas to a C40 Natural Product By Biologic/Inorganic Hybrid Catalysis

Over one-third CO₂ emission arises from industry, and valorization of CO₂ in industrial exhaust gas is key to establishing a carbon-neutral society. However, there has been few reports on the conversion of CO₂ from real industrial exhaust gas to complex and value-added chemicals. Although electrochemical CO₂ reduction has been attracted increasing attention and great progress has been achieved, the product profiles based on inorganic catalysis are only limited to a few simple chemicals, such as formate, acetate, and ethanol. Optionally, biocatalysis can convert CO₂ to more complex chemicals, while the supply of reducing power remains a grand challenge. Therefore, the coupling of inorganic electrochemical catalysis and biocatalysis offers a promising route for powering sustainable CO₂ conversion with renewable electricity. Herein, we successfully achieved the production of lycopene using real exhaust gas from a coal-fired power plant for the first time, which represented the most complex nonnative molecules from CO₂ reduction. By coupling de novo lycopene biosynthesis with water electrolysis, a microbial electrosynthesis (MES) system was developed. Taking advantage of this biologic/inorganic hybrid catalysis, lycopene was produced with CO₂ as the sole carbon source and H₂ derived from electrochemical water splitting as the reducing power. Moreover, the produced lycopene provided long-term cytoprotective capacity against reactive oxygen species, which addressed the incompatibility between biological and electrochemical catalysis. The maximum yield of lycopene was 1.73 mg/L when real exhaust gas was used as feedstock, which indicated the developed MES system was sustainable and robust, and with great potential for practical application in CO₂ valorization. The present study opens a possible route to turn trash to cash for industrial exhaust gas.