Pulsing to Mitigate Carbon Monoxide Poisoning in Electrochemical Hydrogen Pump

Electrochemical hydrogen pumps (EHPs) efficiently separate hydrogen from mixed product gas streams of the water gas shift reaction using Pt or PtRu/C catalysts. However, these streams often contain carbon monoxide (CO), which strongly adsorbs to the catalyst surface, blocking active sites and reducing hydrogen separation efficiency. In this study, oxidation techniques have been studied to reduce CO poisoning impact at different input gas operating conditions. For high temperature (160 °C), dry gas input feed (160 °C), pulsing was employed to promote the thermal desorption of CO from the catalyst. In contrast, for low temperature (< 100 °C) humid gas input feed, pulsed oxidation was found to be an effective method to oxidize the adsorbed CO to CO₂. For both input feeds, it was observed that a higher pulse current (up to 3.5A) and lower pulse width (up to 10s) increased Hydrogen gas separation efficiency. Once the pulse parameters were optimized, up to a 60% performance improvement was observed with feeds containing 1% CO.