Carbon monoxide poisoning and mitigation strategies for polymer electrolyte membrane fuel cells – A review

Abstract

Polymer electrolyte membrane fuel cells (PEMFC) have received much attention due to their high power density, good start-stop capabilities and high gravimetric and volumetric power density compared with other fuel cells. However, certain technological challenges persist, which include the fact that conventional anode electrocatalysts are poisoned by low levels (few ppm) of carbon monoxide (CO). This review considers the mechanism of CO poisoning and the effects that it has on the PEMFC performance. The key parameters affecting CO poisoning are identified and methods used to mitigate the effects are discussed. These mitigation strategies are divided into three groups according to the means by which the technologies are applied: pre-treatment of reformate, on board removal of CO and in operando mitigation strategies.

Proton conductive Zr-based MOFs

“…The oxidized product Zr-BTNDC-ox was obtained by stirring Zr-BTNDC in a solution of 30% H 2 O 2 aqueous solution for one day. 1 H NMR spectra confirmed that SCH 3 units were oxidized to sulfoxide or sulfone units. The PXRD pattern of the oxidized product is almost the same as that of Zr-BTNDC, indicating that the structure has not changed.…”

“…To solve these two problems, people hope to use more clean energy sources or new alternative energy such as fuel cells (FCs). 1 In this context, proton exchange membrane fuel cells (PEMFCs) are favoured by many researchers for their advantages of efficient energy conversion and nearly zero emission and so on. 2 In PEMFCs, a proton exchange membrane (PEM) provides a channel for proton transport, making protons pass across the film from the anode to the cathode, and forming a circuit with the electron transfer in the external circuit to provide current to the outside world.…”

“…[2][3][4][5] To date, the most commonly used PEM is the Nafion series perfluorinated sulfonic acid membrane with high proton conductivity (σ) and good chemical stability. Nevertheless, such a membrane has the following disadvantages: (1) it is very difficult to synthesize and sulfonate perfluorinated substances, which makes the film formation difficult and leads to high costs; (2) requirements of high temperature and H 2 O content. The optimal operating temperature of Nafion series films is 70-90°C; exceeding this temperature range will cause a sharp decrease in water content and a rapid decline in electrical conductivity; (3) some hydrocarbons, such as methanol (MeOH), have high permeability and are not suitable for use as PEMs in direct methanol fuel cells (DMFC).…”

A review of gas diffusion layer properties and water management in proton exchange membrane fuel cell system

“…Carbon corrosion and poisoning have been reported to be influential in the degradation and failure of the PEMFCs 148,149 …”

“…146,147 Carbon corrosion and poisoning have been reported to be influential in the degradation and failure of the PEMFCs. 148,149 The system of carbon corrosion includes carbon reacting with water and producing carbon dioxide (CO 2 ).Though this reaction process infers that carbon is thermodynamically unstable to electrochemical carbon corrosion, the moderate energy of this response makes it conceivable to utilize carbon in PEMFCs. Nonetheless, irregular operating conditions, for example, the air/hydrogen boundary that occurs during the shut-down/ start-up operation at the anode, increment the cathode potential to a level higher than the open circuit voltage.…”