Hydrogen storage/release properties of Pd/ZrO2 composites prepared from oxidized Zr65Pd35 alloy glass

In this study, the formation and the hydrogen storage/release properties of Pd/ZrO 2 composite materials derived from an amorphous Zr 65 Pd 35 alloy were examined. The XRD and surface morphology of the amorphous Zr 65 Pd 35 after heat treatment in air at 280–800 °C showed the precipitated structure consisting of metallic Pd particles on the matrix of ZrO 2 . The two-step hydrogen storage phenomenon was found to be related to both the matrix and the intrinsic effects on the Pd phase in the composite. The initial process involved the spillover of hydrogen absorbed. In the subsequent plateau region of the hydrogen pressure-concentration (PCT) isotherm, an increasing tendency of hydrogen storage capacity was observed with increasing crystallite size of Pd. In the equilibrium absorption process, the ΔH ° of approximately 38 kJ/mol was proposed to be as the bulk state of Pd for the hydride formation reaction. The temperature programmed reduction (TPR) results exhibited the rapid hydrogen absorption/release behavior on the composite. The desorption of H 2 occurred at temperatures of 65–67 °C and the amount followed the capacity difference with temperature in the pressure plateau region in the PCT profiles. The findings offer the novel knowledge of the composite structure and fabrication and the overall hydrogen absorption/desorption properties of a novel type of hydrogen storage material prepared from an alloy glass. • The Zr 65 Pd 35 glass heated in air at 280–800 °C became the precipitated structure of metallic Pd particles on the ZrO 2 matrix. • The PCT isotherms of the Pd/ZrO 2 composite exhibited the characteristic two-step hydrogen storage behaviors. • The process involved the spillover of hydrogen initially absorbed by Pd/ZrO 2 , depending on the particle size of Pd. • The release of H 2 occurred at 65-68 °C with the full capacity of the hydride by equilibrium storage profiles.