{"title":"Non-stoichiometric Ni3ZnC0.7 carbide loading on melamine sponge-derived carbon for hydrogen storage performance improvement of MgH2","authors":"Zi-Yin Dai, Ping Wu, Li-Rong Xiao, Hideo Kimura, Chuan-Xin Hou, Xue-Qin Sun, Si-Jie Guo, Wei Du, Xiu-Bo Xie","doi":"10.1007/s12598-024-02943-y","DOIUrl":null,"url":null,"abstract":"<div><p>The high operating temperatures and slow kinetics limit the application of MgH<sub>2</sub>-based hydrogen storage materials. Here, a composite of Ni<sub>3</sub>ZnC<sub>0.7</sub>/carbon nanotubes loaded onto a melamine sponge-derived carbon (MS) skeleton is prepared and loaded onto MgH<sub>2</sub>. During dehydrogenation, Ni<sub>3</sub>ZnC<sub>0.7</sub> reacts with MgH<sub>2</sub> and in situ changes to Mg<sub>2</sub>Ni/Zn. The transformation of Mg<sub>2</sub>Ni/Mg<sub>2</sub>NiH<sub>4</sub> serves as a “hydrogen pump”, providing diffusion channels for hydrogen atoms and molecules to promote the de-/hydrogenation processes. Moreover, Zn/MgZn<sub>2</sub> provides the catalytic sites for the transformation of Mg/MgH<sub>2</sub>. The length of the Mg–H bond is elongated from 1.72 to 1.995 Å, and the dissociation energy barrier of MgH<sub>2</sub> is reduced from 1.55 to 0.49 eV. As a result, MgH<sub>2</sub> with 2.5 wt% MS@Ni<sub>3</sub>ZnC<sub>0.7</sub> can absorb 5.18 wt% H<sub>2</sub> at 423 K within 200 s, and its initial dehydrogenation temperature is reduced to 585 K. After 20 cycles, the dehydrogenation capacity retention is determined to be 94.6%. This work demonstrates an efficient non-stoichiometric metal carbide catalyst for MgH<sub>2</sub>.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":"44 1","pages":"515 - 530"},"PeriodicalIF":9.6000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rare Metals","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s12598-024-02943-y","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The high operating temperatures and slow kinetics limit the application of MgH2-based hydrogen storage materials. Here, a composite of Ni3ZnC0.7/carbon nanotubes loaded onto a melamine sponge-derived carbon (MS) skeleton is prepared and loaded onto MgH2. During dehydrogenation, Ni3ZnC0.7 reacts with MgH2 and in situ changes to Mg2Ni/Zn. The transformation of Mg2Ni/Mg2NiH4 serves as a “hydrogen pump”, providing diffusion channels for hydrogen atoms and molecules to promote the de-/hydrogenation processes. Moreover, Zn/MgZn2 provides the catalytic sites for the transformation of Mg/MgH2. The length of the Mg–H bond is elongated from 1.72 to 1.995 Å, and the dissociation energy barrier of MgH2 is reduced from 1.55 to 0.49 eV. As a result, MgH2 with 2.5 wt% MS@Ni3ZnC0.7 can absorb 5.18 wt% H2 at 423 K within 200 s, and its initial dehydrogenation temperature is reduced to 585 K. After 20 cycles, the dehydrogenation capacity retention is determined to be 94.6%. This work demonstrates an efficient non-stoichiometric metal carbide catalyst for MgH2.
期刊介绍：
Rare Metals is a monthly peer-reviewed journal published by the Nonferrous Metals Society of China. It serves as a platform for engineers and scientists to communicate and disseminate original research articles in the field of rare metals. The journal focuses on a wide range of topics including metallurgy, processing, and determination of rare metals. Additionally, it showcases the application of rare metals in advanced materials such as superconductors, semiconductors, composites, and ceramics.
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