Artificial Carbon Neutrality Through Aprotic CO₂ Splitting

Global climate change mitigation necessitates global efforts to reduce CO₂ emissions. Natural photosynthesis exemplifies an ingenious approach to carbon neutrality, converting CO₂ into O₂ and glucose through light and dark reactions. Inspired by the hydrogen-involved processes in photosynthesis, an aprotic electrochemical strategy for CO₂ splitting into O₂ and carbon using lithium as a reducing mediator is presented. The designed electrochemical device features a gas cathode with a nanoscale Co catalyst and a metallic lithium anode. When CO₂ is introduced to the cathode, it undergoes a two-step lithium-related electrochemical reduction, converting it sequentially into Li₂CO₃ and Li₂O. Li₂O is then oxidized to produce O₂ gas at the expense of renewable electrical energy. This process achieves an impressive O₂ yield exceeding 94.7%, significantly outperforming the efficiency of natural photosynthesis. Moreover, the O₂ yield can be further increased to 98.6% by employing an optimized RuCo catalyst. This study offers a new practical and controllable pathway to produce O₂ from CO₂, strongly promoting the sustainable development of human society for realizing carbon neutrality as well as exploring and conquering nature.