Energy- and carbon-efficient CO2/CO electrolysis to multicarbon products via asymmetric ion migration-adsorption

Carbon dioxide/monoxide (CO2/CO) electrolysis provides a means to convert emissions into multicarbon products. However, impractical energy and carbon efficiencies limit current systems. Here we show that these inefficiencies originate from uncontrolled gas/ion distributions in the local reaction environment. Understanding of the flows of cations and anions motivated us to seek a route to block cation migration to the catalyst surface-a strategy we instantiate using a covalent organic framework (COF) in bulk heterojunction with a catalyst. The pi-conjugated hydrophobic COFs constrain cation (potassium) diffusion via cation-pi interactions, while promoting anion (hydroxide) and gaseous feedstock adsorption on the catalyst surface. As a result, a COF-mediated catalyst enables electrosynthesis of multicarbon products from CO for 200 h at a single-pass carbon efficiency of 95%, an energy efficiency of 40% and a current density of 240 mA cm(-2).

二氧化碳/一氧化碳（CO₂/CO）电解提供了一种将排放物转化为多碳产物的方法。然而，不切实际的能量和碳效率限制了当前的系统。在此我们表明，这些低效源于局部反应环境中不受控制的气体/离子分布。对阳离子和阴离子流动的理解促使我们寻求一种阻止阳离子迁移到催化剂表面的途径——我们通过一种与催化剂形成体异质结的共价有机框架（COF）来实现这一策略。π共轭疏水COF通过阳离子 - π相互作用限制阳离子（钾）扩散，同时促进阴离子（氢氧根）和气态原料在催化剂表面的吸附。结果，一种由COF介导的催化剂能够在单次通过碳效率为95%、能量效率为40%以及电流密度为240 mA/cm²的条件下从CO电合成多碳产物达200小时。