Here, we report on the hydriding behaviour of various Mg–Ni alloys in the presence of N2gaseous impurities using in situ synchrotron XRD. We find that a N2content as low as 0.5 mol.% can completely inhibit the hydriding of pure Mg2Ni whereas the Na-modified equivalent remains relatively unaffected even at N2concentrations of up to 5 mol.%. The activated hypoeutectic Mg–Ni alloy demonstrates excellent hydriding kinetics compared to the as-cast counterpart under 1 mol.% of N2. Surface analysis shows it is the electropositive nature of a Na-modified Mg–Ni surface that facilitates selective adsorption of N2while leaving metallic Ni available for H2adsorption/dissociation. The results are important in designing Mg–Ni alloys with tailored properties that are suitable for use in hydrogen storage/purification/separation applications.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology