TY - JOUR
T1 - Geometric Catalyst Utilization in Zero-Gap CO2Electrolyzers
AU - Subramanian, Siddhartha
AU - Yang, Kailun
AU - Li, Mengran
AU - Sassenburg, Mark
AU - Abdinejad, Maryam
AU - Irtem, Erdem
AU - Middelkoop, Joost
AU - Burdyny, Thomas
PY - 2022
Y1 - 2022
N2 - The electrochemical reduction of CO2 (CO2RR) on silver catalysts has been demonstrated under elevated current density, longer reaction times, and intermittent operation. Maintaining performance requires that CO2 can access the entire geometric catalyst area, thus maximizing catalyst utilization. Here we probe the time-dependent factors impacting geometric catalyst utilization for CO2RR in a zero-gap membrane electrode assembly. We use three flow fields (serpentine, parallel, and interdigitated) as tools to disambiguate cell behavior. Cathode pressure drop is found to play the most critical role in maintaining catalyst utilization at all time scales by encouraging in-plane CO2 transport throughout the gas-diffusion layer (GDL) and around salt and water blockages. The serpentine flow channel with the highest pressure drop is then the most failure-resistant, achieving a CO partial current density of 205 mA/cm2 at 2.76 V. These findings are confirmed through selectivity measurements over time, double-layer capacitance measurements to estimate GDL flooding, and transport modeling of the spatial CO2 concentration.
AB - The electrochemical reduction of CO2 (CO2RR) on silver catalysts has been demonstrated under elevated current density, longer reaction times, and intermittent operation. Maintaining performance requires that CO2 can access the entire geometric catalyst area, thus maximizing catalyst utilization. Here we probe the time-dependent factors impacting geometric catalyst utilization for CO2RR in a zero-gap membrane electrode assembly. We use three flow fields (serpentine, parallel, and interdigitated) as tools to disambiguate cell behavior. Cathode pressure drop is found to play the most critical role in maintaining catalyst utilization at all time scales by encouraging in-plane CO2 transport throughout the gas-diffusion layer (GDL) and around salt and water blockages. The serpentine flow channel with the highest pressure drop is then the most failure-resistant, achieving a CO partial current density of 205 mA/cm2 at 2.76 V. These findings are confirmed through selectivity measurements over time, double-layer capacitance measurements to estimate GDL flooding, and transport modeling of the spatial CO2 concentration.
UR - http://www.scopus.com/inward/record.url?scp=85143622288&partnerID=8YFLogxK
U2 - 10.1021/acsenergylett.2c02194
DO - 10.1021/acsenergylett.2c02194
M3 - Article
AN - SCOPUS:85143622288
SN - 2380-8195
VL - 8
SP - 222
EP - 229
JO - ACS Energy Letters
JF - ACS Energy Letters
IS - 1
ER -