This work focuses on a novel synthesis route, using citric acid as a chelating agent, for the formation of gamma-Mo2N and Co3Mo3N bulk catalyst and their application for NH3 decomposition reaction for hydrogen production having its application for onboard generation of hydrogen for fuel cell in transportation vehicles. Successful formation of the pure bulk phase of Co3Mo3N was confirmed by using XRD, XPS, HRTEM techniques. The prepared Co3Mo3N catalyst showed high surface area 15.23 m(2)/g and high catalytic activity compared to bulk gamma-Mo2N for this decomposition reaction, having 97% conversion of NH3 at 550 degrees C at 6000 h(-1). (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.