Abstract For obtaining relevant information about the development of hydrogen storage materials from metal organic frameworks (MOFs), MIL-101(Cr) was selected and synthesized for analyzing the adsorption equilibrium and characteristics of charge and discharge. The specific surface area, pore size distribution (PSD) of the sample were determined by 77.15K nitrogen adsorption data. Isotherms of hydrogen adsorption on the sample were volumetrically measured at 77.15K and 87.15K, 0-100KPa and 0-8MPa. Henry law constants and Toth equation were respectively used to determine the isosteric heat of adsorption. A 3.2L conformable vessel, which can meet the fuel consumption of 7.5kW PEMFC under typical working condition for about 10 minutes, was designed and undergone charge and discharge tests at ambient temperature and 77.15K under the flow rate 10-50L·min-1. Results show that the limit isosteric heat of adsorption on the sample is 7.15kJ·mol-1, while the mean Isosteric heat determined by the Toth potential function is 2.42kJ·mol-1. Results also reveal that, at 77.15K, the ratio of hydrogen released is 80%, 79.4%, 77.2% and 76.1% at the flow rate of 20-50L·min-1; while at 301.15K, the ratio is 85.1%, 85.0% and 82.3% with corresponding flow rate 10-30L·min-1. It suggests that the storage amount and the characteristics of charge/discharge on hydrogen-MIL-101(Cr) system at cryogenic temperature can meet the fuel requirements of the fuel cell.

中文翻译：

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MOFs上氢的吸附平衡和充放电特性

摘要 为了获得金属有机骨架（MOFs）储氢材料发展的相关信息，选择并合成了MIL-101（Cr）用于分析吸附平衡和充放电特性。样品的比表面积、孔径分布(PSD)由77.15K氮吸附数据确定。在 77.15K 和 87.15K、0-100KPa 和 0-8MPa 下对样品的氢吸附等温线进行了体积测量。分别用亨利定律常数和托特方程确定等量吸附热。设计了3.2L符合性容器，在典型工况下可满足7.5kW PEMFC燃料消耗约10分钟，并在常温和77℃下进行充放电试验。15K下流量10-50L·min-1。结果表明，样品的极限等量吸附热为7.15kJ·mol-1，而由Toth势函数确定的平均等量热为2.42kJ·mol-1。结果还表明，在77.15K时，在20-50L·min-1的流速下，释放的氢气比例分别为80%、79.4%、77.2%和76.1%；而在301.15K时，比值分别为85.1%、85.0%和82.3%，相应的流量为10-30L·min-1。表明氢-MIL-101(Cr)系统在低温下的储存量和充放电特性可以满足燃料电池的燃料要求。在20-50L·min-1的流量下放氢比例为80%、79.4%、77.2%和76.1%；而在301.15K时，比值分别为85.1%、85.0%和82.3%，相应的流量为10-30L·min-1。表明氢-MIL-101(Cr)系统在低温下的储存量和充放电特性可以满足燃料电池的燃料要求。在20-50L·min-1的流量下放氢比例为80%、79.4%、77.2%和76.1%；而在301.15K时，比值分别为85.1%、85.0%和82.3%，相应的流量为10-30L·min-1。表明氢-MIL-101(Cr)系统在低温下的储存量和充放电特性可以满足燃料电池的燃料要求。