Hydrogen permeation across super-thin membrane and the burning limitation in low-temperature proton exchange membrane fuel cell

Poor mechanical stability of the polymer electrolyte membranes remains one of the bottlenecks towards improving the performance of the proton exchange membrane (PEM) fuel cells. The present work proposes a unique way to utilize crystalline covalent organic frameworks (COFs) as a self‐standing, highly flexible membrane to further boost the mechanical stability of the material without compromising its innate structural characteristics. The as‐synthesized p‐toluene sulfonic acid loaded COF membranes (COFMs) show the highest proton conductivity (as high as 7.8×10−2 S cm−1) amongst all crystalline porous organic polymeric materials reported to date, and were tested under real PEM operating conditions to ascertain their practical utilization as proton exchange membranes. Attainment of 24 mW cm−2 power density, which is the highest among COFs and MOFs, highlights the possibility of using a COF membrane over the other state‐of‐the‐art crystalline porous polymeric materials reported to date.

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Section: Figuresupporting

confidence: 72%

Superprotonic Conductivity in Flexible Porous Covalent Organic Framework Membranes

et al. 2018

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“…Thus, for the current stack, the optimum values of parameters for the high stack performance as well as the high hydrogen utilization were: a purging period of 3 min, a purging duration of 4 s, and a cathode stoichiometry of 200%. Note that this study was performed at ambient operating pressure as listed in Table 1, the optimum parameters may change at a different operating pressure as it affects the rate of gas permeation across the membrane, as was reported by Ye et al 34. We will consider this effect in future work.…”

Section: Resultsmentioning

confidence: 89%

A Factorial Study to Investigate the Purging Effect on the Performance of a Dead‐End Anode PEM Fuel Cell Stack

2014

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This paper presents an experimental investigation of the effect of hydrogen purging time period and duration on the performance of a proton exchange membrane (PEM) fuel cell stack with a dead-end anode. The objective is to develop a better understanding of the interactions between the purging parameters and the cathode air-stoichiometry. It employs a full factorial approach for three factors (purging period, purging duration and air-stoichiometry) with two levels and three replications. The study is performed on a 300 cm 2 , 24-cell PEM fuel cell stack with the rated power of 1.5 kW. The stack was operated with water cooling, fully humidified air and dry hydrogen at the ambient pressure. The results showed that the stack performance is significantly influenced by the interactions of the purging parameters and the cathode air-stoichiometry. The least square model was utilized to determine the optimum values of these parameters with regard to the stack performance and hydrogen utilization. For the present stack, the optimum values of parameters were: purging period of 3 min, purging duration of 4 s and the cathode air-stoichiometry of 200%.

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“…Thesteady OCV also substantiates the ability of the COFMs to prevent any crossover of the reactant gases.N ormally,H 2 crossover results in the drop in the OCV and the steady OCV obtained here confirms that COFM is impermeable to molecular hydrogen. [13] Upon polarization, the COFMbased MEA delivers am aximum power output of 24 mW cm À2 (at 0.33 V) and am aximum current density of 90 mA cm À2 (at 0.20 V; Figure 4b). It is to be noted that no back pressure was being applied throughout the study.T hus, this study in the fuel-cell polarization mode validates the functioning of the single cell assembled using the COFMs.…”

Section: Angewandte Chemiementioning

confidence: 99%

Superprotonic Conductivity in Flexible Porous Covalent Organic Framework Membranes

et al. 2018

View full text Add to dashboard Cite

Poor mechanical stability of the polymer electrolyte membranes remains one of the bottlenecks towards improving the performance of the proton exchange membrane (PEM) fuel cells. The present work proposes a unique way to utilize crystalline covalent organic frameworks (COFs) as a self-standing, highly flexible membrane to further boost the mechanical stability of the material without compromising its innate structural characteristics. The as-synthesized p-toluene sulfonic acid loaded COF membranes (COFMs) show the highest proton conductivity (as high as 7.8×10 S cm ) amongst all crystalline porous organic polymeric materials reported to date, and were tested under real PEM operating conditions to ascertain their practical utilization as proton exchange membranes. Attainment of 24 mW cm power density, which is the highest among COFs and MOFs, highlights the possibility of using a COF membrane over the other state-of-the-art crystalline porous polymeric materials reported to date.

show abstract

Hydrogen permeation across super-thin membrane and the burning limitation in low-temperature proton exchange membrane fuel cell

Cited by 26 publications

References 37 publications

Superprotonic Conductivity in Flexible Porous Covalent Organic Framework Membranes

Superprotonic Conductivity in Flexible Porous Covalent Organic Framework Membranes

A Factorial Study to Investigate the Purging Effect on the Performance of a Dead‐End Anode PEM Fuel Cell Stack

Superprotonic Conductivity in Flexible Porous Covalent Organic Framework Membranes

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