Hydrogen generation kinetics via hydrolysis of Mg2Ni and Mg2NiH4 powders. (22nd October 2021)

• Record Type: Journal Article
• Authors: Varnagiris, Sarunas; Urbonavicius, Marius
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 73(2021)
• Page Start: 36323
• Page End: 36335
• Publication Date: 2021-10-22
• Subjects: Hydrogen generation -- Hydrolysis -- Mg2NiH4 -- Fuel cell -- Electricity generation -- Chemical bonds; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.08.139
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this work, we produce Mg2 NiH4 powder after hydrogenation of Mg2 Ni and employ them for hydrogen generation via hydrolysis reaction in different type of solutions. The analysis of Mg2 NiH4 powder reveals surface changes after hydrogenation process which induces the occurrence of cracks and alterations of chemical bonds. The extremely intense hydrogen kinetics is observed using acidic solution, with hydrogen generation rate of approx. 600 ml g −1 ·min −1 in the first reaction minute. The activation energy for the hydrolysis of Mg2 NiH4 is calculated to be 29.45 kJ mol −1 . An ageing experiment, which includes Mg2 NiH4 powder stored for two months, discloses almost identical hydrogen generation volume as as-received Mg2 NiH4 powder. Furthermore, the hydrolysis reaction between Mg2 NiH4 and acidic solution is applied for electricity production via PEM fuel cell, which shows the maximum voltage generation of 1.28 V for more than 400 s with the external resistance of 200 Ω. Graphical abstract: Image 1 Highlights: Mg2 NiH4 was prepared by hydrogenating industrial Mg2 Ni powder. Hydrogenation invokes alterations of surface morphology and chemical bonds. Hydrolysis reaction showed hydrogen generation rate of 600 ml g −1 ·min −1 . The activation energy of Mg2 NiH4 powder was calculated at 29.45 kJ ·mol −1 . Mg2 NiH4 powder showed the same hydrogen yields even after two-months of storage.