Synthesis and electrochemical study of nanoporous Pd-Ag alloys for hydrogen sorption

We report on the synthesis of novel nanoporous Pd-Ag electrocatalysts using a facile hydrothermal method where the portion of Ag was varied from 0 to 40%. Scanning electron microscopy (SEM) was used to examine the morphologies of the prepared nanoporous materials. Energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma (ICP) were used to directly and indirectly characterize the composition of the formed Pd-Ag nanostructures. X-ray diffraction (XRD) analysis confirmed that the formed Pd-Ag nanomaterials were alloys with a face-centered cubic structure. Electrochemical methods were used to study the capacity and kinetics of hydrogen sorption into the nanoporous Pd and Pd-Ag alloys. The nanoporous Pd-Ag alloy with 20% silver possesses the highest capacity for the alpha phase hydrogen sorption, which is over 4 times higher than the pure nanoporous Pd. The combination of the enhanced alpha phase hydrogen sorption capacity and diminishing of the alpha- and beta-phase transition makes the nanoporous Pd-Ag alloys promising for hydrogen selective membranes and hydrogen dissociation catalysts. (C) 2010 Elsevier Ltd. All rights reserved.