Remarkable hydrogen absorption/desorption behaviors and mechanism of sodium alanates in-situ doped with Ti-based 2D MXene

AbstractA remarkable reduction in reaction temperature was found for the hydrogenation of Li metal in Li-C mixture. H2 uptake started at 50°C, became vigorous at 150°C and slowed down at temperatures above 200°C. In-situ XRD characterizations revealed that Li-C intercalation compounds such as LiC6 and LiC12 existed in the Li-C samples, and LiH formed after the hydrogenation taking place. Increasing the carbon content in the Li-C mixture, from Li/C = 10:1 to 5:1 and then to 2:1, would enhance the reactivity of hydrogenation accordingly. Carbon nanotubes, with smaller size and larger specific area, showed even greater enhancement of the hydrogenation of lithium metal than graphite. The mechanism for the low temperature hydrogenation of Li-C samples was studied and discussed.

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Catalytic mechanism of in-situ Ni/C co-incorporation for hydrogen absorption of Mg

Journal of Magnesium and Alloys ◽

10.1016/j.jma.2021.08.019 ◽

2021 ◽

Author(s):

Bogu Liu ◽

Bao Zhang ◽

Haixiang Huang ◽

Xiaohong Chen ◽

Yujie Lv ◽

...

Keyword(s):

Hydrogen Absorption ◽

Catalytic Mechanism

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Hydrogen-Induced Phase Separation of Palladium-Rhodium Alloys Using an Environmental Cell TEM

Microscopy and Microanalysis ◽

10.1017/s1431927600009843 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 591-592

Author(s):

D.F. Teter ◽

R.D. Field ◽

D.J. Thoma

Keyword(s):

Phase Separation ◽

Hydrogen Absorption ◽

Melt Spinning ◽

Room Temperature ◽

Annealing Treatment ◽

Miscibility Gap ◽

Environmental Cell ◽

Cold Rolled ◽

Kinetics Of

The palladium-rhodium system has been extensively studied for its hydrogen absorption characteristics. However, the phase diagram of the palladium-rhodium system has not been conclusively determined below 800 K. Shield and Williams have experimentally determined the incoherent miscibility gap in Pd-Rh alloys using electrical resistivity studies, however the coherent miscibility gap and spinodal have not been determined. Recently work by Noh and Flanagan has suggested that hydrogen enhances metal atom mobility and may increase the kinetics of phase separation in Pd-Rh alloys. Field and Thoma found that hydrogen causes a Pd-10%Rh alloy to decompose during an in situhydrogen charging experiment in an environmental cell TEM. According to the calculations by Gonis et al. of the miscibility gap for the palladium-rhodium system, the Pd-10%Rh alloy may be within the chemical spinodal at room temperature.In this work, two palladium-rhodium compositions were investigated. The first was a Pd-10 at.% Rh alloy produced by melt-spinning, and the second was a Pd-30at.%Rh alloy which had been arc-melted and cold rolled followed by an annealing treatment to homogenize the material. TEM specimens were prepared by punching 3 mm disks from the material.

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