Electrochemical Hydrogen Pump – Methods to Combat CO Poisoning

As global demand for hydrogen grows, both as a clean energy carrier and an industrial fuel, electrochemical hydrogen pumps (EHPs) are gaining attention for their ability to separate and compress hydrogen efficiently. EHPs work by selectively drawing hydrogen from low-pressure hydrogen gas mixtures and electrochemically converting it into high-purity, high-pressure hydrogen. EHPs are particularly useful for purifying hydrogen from industrial byproducts like syngas, an industrial mixture containing hydrogen and carbon monoxide (CO). However, CO binds to the platinum catalyst used in EHPs and reduces its effectiveness – a problem known as catalyst poisoning. This literature review explores a range of strategies being developed to address CO poisoning in EHPs, including catalyst modifications (such as platinum alloys and platinum group metal-free alternatives), membrane material innovations (e.g., ion exchange vs. proton exchange membranes), and operational methods like high-temperature systems and pulsing techniques. Pulsing strategies involve either modulating the applied current or using oxygen "bleeds" to regenerate poisoned catalysts. These approaches are compared based on key performance metrics such as hydrogen output, faradaic efficiency, and long-term stability. The paper also discusses where each method works best, their trade-offs, and provides a clearer picture of how to build more CO-tolerant and efficient EHP systems.