Highly selective and stackable electrode design for gaseous CO2 electroreduction to ethylene in a zero-gap configuration
Woong Hee Lee, Chulwan Lim, Si Young Lee, Keun Hwa Chae, Chang Hyuck Choi, Ung Lee, Byoung Koun Min, Yun Jeong Hwang, Hyung‐Suk Oh
Abstract
The electrochemical reduction of CO2 to ethylene has the potential to reduce greenhouse gas emissions while producing commodity chemicals for plastics; however, a scalable and feasible system for this remains a challenge. Herein, we report an efficient and stackable electrode design for the electrolysis of CO2 to ethylene. Using KOH-incorporated Cu nanoparticle (Cu-KOH) as the cathode in a zero-gap electrolyzer, Faradaic efficiency of 78.7% for C2 products was achieved at a current density of 281 mA cm–2. Among C2 products, ethylene with a 54.5% FE was dominant product. For mass production, three membrane electrode assemblies (MEAs) were stacked and operated. Operando X-ray absorption spectroscopy under the zero-gap electrolyzer suggested mainly metallic Cu state with some persistent oxide-derived Cu species in Cu-KOH, including Cu2O and Cu(OH)2, which expected a synergistic effect for the conversion of CO2 to C2H4. Our findings provide a new strategy for converting CO2 to C2H4, which is expected to accelerate the commercialization of high-value chemical production through electrochemical CO2 reduction.