Microstructure and first hydrogenation properties of TiFe alloy with Zr and Mn as additives

摘要

In this paper, the effect of Zr and Mn on the microstructure and first hydrogenation kinetic of TiFe alloy is reported. TiFe alloy to which Zr, Mn or a combination of both have been added were synthesized by induction melting. First hydrogenation of all alloys was performed at room temperature under 20 bar of hydrogen. We found that addition of manganese makes possible activation at room temperature, but kinetics was very sluggish. Alloy with 2 wt% Zr did not absorb hydrogen. However, with addition of 4 wt% Zr, the alloy absorbed 1.2 wt% of hydrogen. A synergetic effect was found when zirconium was added along with manganese. Alloy with 1 wt% Mn and 2 wt% Zr had better kinetics than the alloy having only Mn or only Zr. The maximum hydrogen capacity was also greater at similar to 1.8 wt% after 7 h. Combination of 4 wt% Zr and 2 wt% Mn absorbed 2 wt% of hydrogen in 5 h. The rate limiting step for each activated alloy was found to be diffusion controlled with decreasing interface velocity. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.