Fabrication of a Porous Flow-Through Electrode for CO_2 Reduction to CO in Organic Electrolyte with HCl Oxidized to Cl_2 on Anode

摘要

Carbon dioxide (CO_2) can be electrochemically reduced to value-added fuels and chemicals, which offers a promising way for CO_2 recycling utilization. In the present work, we have designed a membrane electrolyzer for CO_2 reduction to carbon monoxide (CO) in organic electrolyte, with hydrochloric acid (HCl) oxidized to chlorine (Cl_2) on the anode. The obtained CO and Cl_2 can be used as feedstock to produce phosgene. Using this method, CO_2 can be converted into high-value products, and Cl_2 can be recovered from industrial off-gases, which contain HCl. To substantially increase the current density of CO_2 electroreduction, we have proposed a novel noncyanide electroplating method to deposit Au on Cu foam to fabricate a porous flow-through electrode. By enlarging the specific surface area of the cathode, and providing a large amount of Au nanoparticles for CO_2 electroreduction,the cathodic current density has been increased to 106 Ma?cm~(-2), with faradic efficiency of CO formation stabilized at 90%. On the anode, the faradic efficiency of Cl_2 generation is stabled at 92%, with the anodic current density archived to 42 mAcm~(-2). Such designed electrolysis cell has a broad application prospect in the chemical industry.