Mg-based composites for enhanced hydrogen storage performance. (1st January 2019)

• Record Type: Journal Article
• Authors: Tian, Mi; Shang, Congxiao
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 1(2019)
• Page Start: 338
• Page End: 344
• Publication Date: 2019-01-01
• Subjects: Mg-based composites -- Hydrogen storage -- Carbon; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.02.119
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Hydrogen storage in solids of hydrides is advantageous in comparison to gaseous or liquid storage. Magnesium based materials are being studies for solid-state hydrogen storage due to their advantages of high volumetric and gravimetric hydrogen storage capacity. However, unfavorable thermodynamic and kinetic barriers hinder its practical application. In this work, we presented that kinetics of Mg-based composites were significantly improved during high energy ball milling in presence of various types of carbon, including plasma carbon produced by plasma-reforming of hydrocarbons, activated carbon, and carbon nanotubes. The improvement of the kinetics and de-/re-hydrogenation performance of MgH2 and TiC-catalysed MgH2 by introduction of carbon are strongly dependent on the milling time, amount of carbon and carbon structure. The lowest dehydrogenation temperature was observed at 180 °C by the plasma carbon–modified MgH2 /TiC. We found that nanoconfinement of carbon structures stabilised Mg-based nanocomposites and hinders the nanoparticles growth and agglomeration. Plasma carbon was found to show better effects than the other two carbon structures because the plasma carbon contained both few layer graphene sheets that served as an active dispersion matrix and amorphous activated carbons that promoted the spill-over effect of TiC catalysed MgH2 . The strategy in enhancing the kinetics and thermodynamics of Mg-based composites is leading to a better design of metal hydride composites for hydrogen storage. Highlights: Novel Mg-based hydrogen storage nanocomposites are prepared by mechanical milling. Mg-based nanocomposites with various carbon structures exhibit excellent de/re-hydrogenation kinetics. Mechanism of carbon structure interacting with Mg and catalysts for the improved hydrogen storage properties is discussed.