Synthesis and electrochemical study of Pd- and Pt- based nanostructured materials

Abstract

We are currently facing climate change and global warming effects due to the emission of greenhouse gases from our existing energy sources. Proton exchange membrane fuel cells are one of the most efficient alternatives for power generation with the potential for greater than 80% efficiency in combined heat and power systems. Pd- and Pt-based catalysts are deemed to hold great potential in many aspects of energy conversion; from the purification and storage of hydrogen as palladium metal hydride (PdHx), to harnessing clean energy via fuel cells. In this M.Sc. study, Pd and Pt-based nanomaterials have been synthesized and examined to elucidate their applications in hydrogen storage and for fuel cell catalysis. The surface properties of the synthesized Pd and Pt-based nanomaterials were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Electrochemical analysis of the fabricated nanomaterials was performed using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). Novel nanoporous Pd-Ag electrocatalysts were synthesized utilizing a facile hydrothermal method. The Ag content of the Pd-Ag alloy varied from 0 to 40%. EDS, XPS and inductively coupled plasma (ICP) were used to directly and indirectly characterize the composition of the formed Pd-Ag nanostructures. XRD analysis confirmed that the Pd-Ag nanomaterials were alloys that contained a face-centered cubic structure.