Proof-of-Concept of the Integrated Methanol Reforming-Desalination Fuel Cell System: Effect of CO₂ and CO on Cell’s Performance

Abstract

Desalination fuel cell (DFC) is an electrochemical cell driven by hydrogen− oxygen redox reactions to simultaneously generate electricity and desalted water. Methanol reforming (MR), although being a relatively well-established method for H 2 generation, produces CO 2 and small amounts of CO. While the detrimental effect of CO on proton exchange membrane fuel cells has been extensively studied, the effect of CO on DFC performance has not yet been investigated. In this study, we introduce a novel integrated MR−DFC system and investigate its performance characteristics experimentally. Specifically, we examined the system's response to the presence of CO 2 and CO in the MR outlet stream that is directly fed to the DFC inlet. Our findings reveal a decrease in the open-circuit voltage (OCV) and limiting current when utilizing the MR outlet as a feed, although the ohmic region remains intact and the desalination process is not affected significantly. Rotating disk electrode (RDE) tests were conducted to validate the observed reduction in the OCV. A stability test was conducted for 25 h, revealing that feeding the MR outlet to DFC initially provides a similar discharge current to that with pure H 2 feed, followed by certain degradation that was attributed to CO poisoning. Our study provides valuable insights into the performance of the integrated MR-DFC unit, advancing the development of this sustainable water-power system.