电化学还原高压CO_(2)捕集溶液制太阳能燃料  

Multiscale model to resolve the chemical environment in a pressurized CO_(2)-captured solution electrolyzer

作　　者：刘宁 陈龙飞 邓楷 冯浩 张莹 段静静 刘东 李强 Ning Liu;Longfei Chen;Kai Deng;Hao Feng;Ying Zhang;Jingjing Duan;Dong Liu;Qiang Li(MIIT Key Laboratory of Thermal Control of Electronic Equipment,School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]MIIT Key Laboratory of Thermal Control of Electronic Equipment,School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China

出　　处：《Science Bulletin》2023年第11期1143-1152,M0004,共11页科学通报（英文版）

基　　金：the National Natural Science Foundation of China(51888103,51976090,and 52006101);Scientific and Technological Innovation Project of Carbon Emission Peak and Carbon Neutrality of Jiangsu Province(BE2022024);the Natural Science Foundation of Jiangsu Province(BK20200491)。

摘　　要：本文突破单一考虑CO_(2)转化的局限,从CO_(2)捕集-转化-利用集成的角度提出了直接光/电化学还原高压CO_(2)捕集溶液制太阳能燃料,在捕集端避免高温条件气相CO_(2)再生步骤;在产无端利用CO_(2)和CO溶解度的巨大差异,实现零能耗气体产物分离;在转化过程中,本文建立了考虑压力的光/电化学CO_(2)还原多尺度方法.本文建立了微观第一性原理计算-介观动力学模拟-宏观输运模型耦合的多尺度模型,以基元反应参数、分电流密度作为跨接参数,以电极表面CO_(2)浓度、pH作为迭代参数,实现了多尺度模拟计算;研究了宏观压力变化对界面微环境(电极表面分子覆盖度和局域pH)的作用机制,发现分子覆盖度对CO_(2)还原反应的促进作用与局域pH对析氢反应的抑制作用相协同,实现了CO_(2)高效、高选择性转化.本文研制了直接光/电化学还原高压CO_(2)捕集溶液制太阳能燃料原理样机,太阳能制燃料效率达到16.8%,超过了文献报道的饱和CO_(2)溶液供给的太阳能制燃料系统.The community of electrochemical CO_(2)reduction is almost exclusively focused on gaseous CO_(2)-fed electrolyzers.Here,we proposed a pressurized CO_(2)-Captured solution electrolyzer to produce solar Fuel of CO(abbreviated“CCF”)without the need to regenerate gaseous CO_(2).Specifically,we developed an experimentally validated multiscale model to quantitatively investigate the effect of pressure-induced chemical environment and to resolve the complex relationship between this effect and the activity and selectivity of CO production.Our results show that the pressure-induced variation of the cathode pH has a negative effect on the hydrogen evolution reaction,whereas the species coverage variation positively affects CO_(2)reduction.These effects are more pronounced at pressures below 15 bar(1 bar=101 kPa).Consequently,a mild increase in the pressure of the CO_(2)-captured solution from 1 to 10 bar leads to a dramatic enhancement in selectivity.Using a commercial Ag nanoparticle catalyst,our pressurized CCF prototype achieved CO selectivity higher than 95%at a low cathode potential of-0.6 V versus reversible hydrogen electrode(RHE),comparable to that under the gaseous CO_(2)-fed condition.This enables the demonstration of a solar-to-CO efficiency of 16.8%,superior to any known devices with an aqueous feed.

关 键 词：促进作用 电化学还原 多尺度模型 燃料效率 多尺度方法 燃料系统 析氢反应 输运模型 

分 类 号：TQ517[化学工程]