A laboratory made 1.5 wt% Palladium (Pd) zeolite electrocatalyst is investigated using the Extended X-ray Adsorption Fine Structure (EXAFS) and Cyclic Voltammetry (CV) techniques to reveal Pd structure and resultant electrochemical performance. It was found that the electrochemical activity of hydrogen charger transfer in the hydride region increased for electrocatalyst with large-size particles made at high temperature of 400 degrees C, compared to those with small-size particles calcined and reduced at temperature below 360 degrees C, at which no major discrepancies were observed between catalysts of different sizes. Furthermore, Pd particle location has played an important role to enhance electrocatalyst performance. The Pd atom tends to remain at small cages, i.e. zeolite sodalite cages or hexagonal prisms at calcinations and reduction temperatures below 360 degrees C. When temperature increases to about 400 degrees C, the majority Pd atoms tend to migrate from zeolite small cages to supercages and zeolite external structures with enhanced electrochemical performance. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.