High structural stability and hydrogen storage properties of nano-porous Zr-Al-Ni-Pd glassy alloy produced by electrochemical dealloying

Abstract Nano-porous glassy Zr60Al5Ni30Pd5 skeleton structure alloy was prepared by electrochemical etching treatment in its glassy phase. The nano-pore size is about 5-15 nm and no nano-phase aggregation phenomenon is recognized. The alloy composition of the nano-porous surface shifted to Zr21.8Al2.4Ni56.1Pd19.7 and the electrochemical treatment caused the enrichment of Ni and Pd elements on the nano-porous surface. The enrichment of Ni and Pd elements leads to the increases of the reaction activity with hydrogen due to Pd catalytic effect through creating diffusion pathway into the bulk of material. The nano-porous glassy alloy has homogeneous distribution of Pd element and exhibits high corrosion resistance. The hydrogen absorption/desorption characteristics cycles with enhanced kinetics are maintained without appreciable degradation up to 20 cycles and the hydrogen absorption capacity reaches about 5.4 wt%. This result indicates the possibility of developing a suitable hydrogen storage material which can reduce the consumption amount of precious Pd metals.