Thangarasu Sadhasivam, Oh Tae Hwan
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea.
Polymers (Basel). 2022 Jun 27;14(13):2608. doi: 10.3390/polym14132608.
In the present scenario, much importance has been provided to hydrogen energy systems (HES) in the energy sector because of their clean and green behavior during utilization. The developments of novel techniques and materials have focused on overcoming the practical difficulties in the HES (production, storage and utilization). Comparatively, considerable attention needs to be provided in the hydrogen storage systems (HSS) because of physical-based storage (compressed gas, cold/cryo compressed and liquid) issues such as low gravimetric/volumetric density, storage conditions/parameters and safety. In material-based HSS, a high amount of hydrogen can be effectively stored in materials via physical or chemical bonds. In different hydride materials, Mg-based hydrides (Mg-H) showed considerable benefits such as low density, hydrogen uptake and reversibility. However, the inferior sorption kinetics and severe oxidation/contamination at exposure to air limit its benefits. There are numerous kinds of efforts, like the inclusion of catalysts that have been made for Mg-H to alter the thermodynamic-related issues. Still, those efforts do not overcome the oxidation/contamination-related issues. The developments of Mg-H encapsulated by gas-selective polymers can effectively and positively influence hydrogen sorption kinetics and prevent the Mg-H from contaminating (air and moisture). In this review, the impact of different polymers (carboxymethyl cellulose, polystyrene, polyimide, polypyrrole, polyvinylpyrrolidone, polyvinylidene fluoride, polymethylpentene, and poly(methyl methacrylate)) with Mg-H systems has been systematically reviewed. In polymer-encapsulated Mg-H, the polymers act as a barrier for the reaction between Mg-H and O/HO, selectively allowing the H gas and preventing the aggregation of hydride nanoparticles. Thus, the H uptake amount and sorption kinetics improved considerably in Mg-H.
在当前情况下，由于氢能系统（HES）在使用过程中具有清洁环保的特性，其在能源领域受到了高度重视。新技术和材料的发展致力于克服氢能系统（生产、储存和利用）中的实际困难。相比之下，由于基于物理的储存方式（压缩气体、冷/低温压缩和液体）存在诸如低重量/体积密度、储存条件/参数以及安全等问题，储氢系统（HSS）需要得到相当多的关注。在基于材料的储氢系统中，可以通过物理或化学键将大量氢气有效地储存在材料中。在不同的氢化物材料中，镁基氢化物（Mg-H）显示出诸多优点，如低密度、吸氢能力和可逆性。然而，其较差的吸附动力学以及暴露于空气中时严重的氧化/污染限制了其优势。人们已经做出了许多努力，比如加入催化剂来改善镁基氢化物的热力学相关问题。不过，这些努力并未克服与氧化/污染相关的问题。用气体选择性聚合物封装镁基氢化物的发展能够有效且积极地影响氢吸附动力学，并防止镁基氢化物受到污染（空气和水分）。在本综述中，系统地回顾了不同聚合物（羧甲基纤维素、聚苯乙烯、聚酰亚胺、聚吡咯、聚乙烯吡咯烷酮、聚偏二氟乙烯、聚甲基戊烯和聚甲基丙烯酸甲酯）对镁基氢化物系统的影响。在聚合物封装的镁基氢化物中，聚合物充当了镁基氢化物与氧气/水之间反应的屏障，选择性地允许氢气通过并防止氢化物纳米颗粒的聚集。因此，镁基氢化物的吸氢量和吸附动力学有了显著改善。
