Isothermal hydrogen production behavior and kinetics of bulk eutectic Mg–Ni-based alloys in NaCl solution

Publication date: Available online 19 September 2019Source: Journal of Alloys and CompoundsAuthor(s): Wei Tan, Yuan-e Yang, Yan-xiong FangAbstractTo seek bulk Mg-based alloys with excellence H2 production properties, smelted eutectic Mg–Ni-based alloys are successfully prepared by metallurgical method. The phase compositions and microstructures are tested by X-ray diffraction (XRD) and scanning electron microscope (SEM). The isothermal H2 production curves of prepared alloys in 3.5 wt% NaCl solution are collected at different temperatures by drainage method. H2 production kinetics and thermodynamics are investigated in combination with the microstructures results and fitting results of hydrolysis curves by Avrami-Erofeev equation and Arrhenius equation. The production capacity for Mg-23.5 wt%Ni (Mg23.5Ni) eutectic alloy is 706 mL g−1 with 0.92 conversion yield at 303 K. When 10 wt% La added, the production capacity and yield of Mg-23.5 wt%Ni-10 wt%La (Mg23.5Ni10La) are 679 mL g−1 and 0.98, respectively. The initial rate and final capacity for H2 production of experimental Mg–Ni-based eutectic alloys improve gradually with the rising reaction temperature. The hydrolysis apparent activation energies for Mg23.5Ni and Mg23.5Ni10La alloys are 40.56 kJ/mol and 31.72 kJ/mol, respectively. The refined lamellar microstructure and the introduced La2Mg17 active phase strongly promote the H2 production process of Mg23.5Ni10La alloy. The reported results pr...

Source: Journal of Alloys and Compounds - September 21, 2019 Category: Chemistry Source Type: research