Preparation and hydrogen storage properties of nanostructured Mg2Cu alloy

We successfully synthesized Mg₂Cu alloys from the metal nanoparticles, which are produced from hydrogen plasma-metal reaction method, in two ways. One is under 0.1 MPa argon at 673 K and the other is under 4.0 MPa hydrogen at 673 K. The structure, morphology and reaction mechanism were studied. The hydrogen absorption and the pressure-composition isotherm properties of the obtained Mg₂Cu alloy under hydrogen were studied. The van’t Hoff equation and the formation enthalpy and entropy of the resulting hydride (MgH₂+MgCu₂) were obtained from the equilibrium plateau pressures of the desorption isotherms. Nanostructured Mg₂Cu shows excellent hydrogen storage properties because nanostructured materials have more surface area and more defects, which means more nucleation sites with hydrogen, and smaller particles, which means shorter diffusion distance for hydrogen in the alloys particles.