Synthesis of La2MgNi9 hydrogen storage alloy in molten salt

Durger N. B., ANIK M.

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, cilt.45, sa.15, ss.8750-8756, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 45 Sayı: 15
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.ijhydene.2020.01.049
  • Dergi Adı: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Artic & Antarctic Regions, Chimica, Communication Abstracts, Compendex, Environment Index, INSPEC
  • Sayfa Sayıları: ss.8750-8756
  • Anahtar Kelimeler: Metal hydrides, Electro-deoxidation, Electrochemical reactions, X-ray diffraction, ELECTROCHEMICAL PROPERTIES, TITANIUM-DIOXIDE, PHASE-STRUCTURE, MG, REDUCTION
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

La2MgNi9 alloy is synthesized directly from the sintered mixture of La2O3 + NiO + MgO in the molten CaCl2 electrolyte by the electro-deoxidation method at 740 degrees C and the electrochemical hydrogen storage characteristics of the synthesized alloy are observed. Sintering (at 1200 degrees C for 2 h) converts the hygroscopic La2O3 (by the reaction with NiO) into the non-hygroscopic La2NiO4 and La3Ni2O7 phases. The X-ray diffraction peaks indicate that the electro-deoxidation causes LaOCl, Ni, LaNi5 and even target phase La2MgNi9 to form within 2 h process time. The molten salt synthesis process ends up with the final alloy structure of 79% La2MgNi9 and 21% retained LaNi5. The porous alloy structure (with approximately 31.66 m(2)g(-1) specific surface area) is beneficial for higher hydrogen storage capacity and it is observed that La2MgNi9 alloy has promising discharge capacity which is approximately 280 mAhg(-1). This work clearly indicates that the electro-deoxidation is a very effective method in the synthesis of the hydrogen storage materials. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.