Hydroxide exchange membrane fuel cells (HEMFCs) are a potentially lower-cost hydrogen fuel cell technology; however, ambient levels of CO2in air significantly reduce HEMFCs’ performance. In this work, we demonstrate an electrochemically-driven CO2separator (EDCS) which can be used to remove ambient levels of CO2from air upstream of the HEMFC stack in fuel cell vehicles, protecting it from CO2-related performance losses. The EDCS operating window was explored for current density, anode flow, and cathode flow with respect to its impact on CO2separation performance. Additionally, gas-phase mass transport was improved by selecting flow fields and gas diffusion layers conducive to the EDCS operating regime. The use of a carbon-ionomer interlayer at the cathode was explored and improved CO2removal performance from 77.7% to 98.2% at 20 mA cm-2. An analytical, 1-D model is used to explain the experimental observations and design improvements. A single-cell, 25 cm2EDCS using the aforementioned improved design demonstrated greater than 98% CO2removal at a cathode flow rate of 1300 sccm for 100 h with 2.7% hydrogen stack consumption.
Matz, Stephanie, et al. "Demonstration of Electrochemically-Driven CO<sub>2</sub> Separation Using Hydroxide Exchange Membranes." Journal of the Electrochemical Society, vol. 168, no. 1, Jan. 2021. https://doi.org/10.1149/1945-7111/abd5fe
Matz, Stephanie, Setzler, Brian P., Weiss, Catherine M., et al., "Demonstration of Electrochemically-Driven CO<sub>2</sub> Separation Using Hydroxide Exchange Membranes," Journal of the Electrochemical Society 168, no. 1 (2021), https://doi.org/10.1149/1945-7111/abd5fe
@article{osti_1848344,
author = {Matz, Stephanie and Setzler, Brian P. and Weiss, Catherine M. and Shi, Lin and Gottesfeld, Shimshon and Yan, Yushan},
title = {Demonstration of Electrochemically-Driven CO<sub>2</sub> Separation Using Hydroxide Exchange Membranes},
annote = {Hydroxide exchange membrane fuel cells (HEMFCs) are a potentially lower-cost hydrogen fuel cell technology; however, ambient levels of CO2in air significantly reduce HEMFCs’ performance. In this work, we demonstrate an electrochemically-driven CO2separator (EDCS) which can be used to remove ambient levels of CO2from air upstream of the HEMFC stack in fuel cell vehicles, protecting it from CO2-related performance losses. The EDCS operating window was explored for current density, anode flow, and cathode flow with respect to its impact on CO2separation performance. Additionally, gas-phase mass transport was improved by selecting flow fields and gas diffusion layers conducive to the EDCS operating regime. The use of a carbon-ionomer interlayer at the cathode was explored and improved CO2removal performance from 77.7% to 98.2% at 20 mA cm-2. An analytical, 1-D model is used to explain the experimental observations and design improvements. A single-cell, 25 cm2EDCS using the aforementioned improved design demonstrated greater than 98% CO2removal at a cathode flow rate of 1300 sccm for 100 h with 2.7% hydrogen stack consumption.},
doi = {10.1149/1945-7111/abd5fe},
url = {https://www.osti.gov/biblio/1848344},
journal = {Journal of the Electrochemical Society},
issn = {ISSN 0013-4651},
number = {1},
volume = {168},
place = {United States},
publisher = {IOP Publishing},
year = {2021},
month = {01}}