Improved hydrogenation kinetics of timn1.52 alloy coated with palladium through electroless deposition
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
MPDI
Abstract
The deterioration of hydrogen charging performances resulting from the surface chemical
action of electrophilic gases such as CO2
is one of the prevailing drawbacks of TiMn1.52 materials.
In this study, we report the effect of autocatalytic Pd deposition on the morphology, structure,
and hydrogenation kinetics of TiMn1.52 alloy. Both the uncoated and Pd-coated materials were
characterized using scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and
X-ray diffraction (XRD). XRD analyses indicated that TiMn1.52 alloy contains C14-type Laves phase
without any second phase, while the SEM images, together with a particle size distribution histogram,
showed a smooth non-porous surface with irregular-shaped particles ranging in size from 1 to 8 µm.
The XRD pattern of Pd-coated alloy revealed that C14-type Laves phase was still maintained upon
Pd deposition. This was further supported by calculated crystallite size of 29 nm for both materials.
Furthermore, a Sieverts-type apparatus was used to study the kinetics of the alloys after pre-exposure
to air and upon vacuum heating at 300 ◦C. The Pd-coated AB2 alloy exhibited good coating quality
as confirmed by EDS with enhanced hydrogen absorption kinetics, even without activation. This
is attributed to improved surface tolerance and a hydrogen spillover mechanism, facilitated by
Pd nanoparticles. Vacuum heating at 300 ◦C resulted in removal of surface barriers and showed
improved hydrogen absorption performances for both coated and uncoated alloys.
Description
Keywords
Hydrogen storage materials, Aluminium bronze, Palladium, Chemistry
Citation
Somo, T. R. et al. (2021). Improved hydrogenation kinetics of timn1.52 alloy coated with palladium through electroless deposition. Materials, 14(8), 1833. https://doi.org/10.3390/ma14081833