标题： 电化学CO2捕获与pH无关的氧化还原化学 显示英文标题

标题： Electrochemical CO2 capture with pH-independent redox chemistry

摘要： 捕获人为来源的CO2对于缓解气候变化至关重要，而降低能耗对于大规模部署是必不可少的。 无机碳在水溶液中的溶解度取决于pH值，而通过电化学调节pH已被研究作为CO2捕获和释放的方法。 然而，已报道的方法由于热力学惩罚而不可避免地产生能耗。 在本研究中，我们引入了一种与pH无关的氧化还原化学反应，通过改变pH而不直接改变[H+]，显著降低了热力学能耗。 我们展示了TEMPO分子的氧化还原反应在流动电池中调节pH，以捕获和释放CO2，其能耗低至2.6 kJ/mol CO2，相当于0.027 eV/分子。 提出了一种分子模型，该模型得到了MD和DFT模拟的支持，说明了pH如何降低7.6，同时大大避免了增加[H+]相关的熵能成本。 我们认为，这项工作展示了与pH无关的氧化还原化学在实际和经济有效的CO2捕获中的潜力。 显示英文摘要

摘要： Capture of anthropogenic CO2 is critical for mitigating climate change, and reducing the energy cost is essential for wide-scale deployment. Solubility of inorganic carbon in aqueous solutions depends on the pH, and electrochemical modulation of the pH has been investigated as a means of CO2 capture and release. However, reported methods incur unavoidable energy costs due to thermodynamic penalties. In this study, we introduce a pH-independent redox chemistry that greatly lowers the thermodynamic energy costs by changing the pH without directly changing the [H+]. We show that the redox reaction of TEMPO molecules modulates the pH for capture and release of CO2 in a flow cell with an energy cost as low as 2.6 kJ/mol of CO2 corresponding to 0.027 eV/molecule. A molecular model, supported by MD and DFT simulations, is proposed of how the pH is decreased by 7.6 while largely avoiding the entropic energy cost associated with increasing the [H+]. We believe that this work showcases the potential of pH-independent redox chemistries for practical and cost-effective CO2 capture.