Efficient and durable porous Membrane-Based CO2 electrolysis for commercial Zero-Gap electrolyzer stack systems

Abstract

This study presents a low-cost CO2 electrolysis stack utilizing a porous-membrane exhibiting good performance and durability. The membrane electrode assembly (MEA), configuration, composed of an Ag cathode, IrO2 anode, and polyvinylidene fluoride (PVDF) porous membrane, was optimized through various single-cell studies. To optimize the process for increasing the area of the reduction electrode, the characteristics of the spray coating method and the electron beam irradiation technology were compared. The Ag electrode fabricated through the e-beam process, exhibited diminished CO2 reduction performance due to low porosity and high carbon monoxide (CO) affinity. A large-scale four-cell CO2 electrolyzer stack (total area: 100 cm2) demonstrated CO mass production with over 80 % selectivity during 110-hour operation at 200 mA cm−2. Moreover, CO production rate was reported as 7.28 L/h, equivalent to 5.63 kWh kg−1 of electricity. Notably, this CO2 electrolysis stack exhibits superior performance and durability compared to previous non-ion-exchange membrane separators reported, offering promising prospects for cost reduction and commercial scaling.