Advanced Nickel-Based Catalysts for the Hydrogen Oxidation Reaction in Alkaline Media Synthesized by Reactive Spray Deposition Technology: Study of the Effect of Particle Size

Anion exchange membrane fuel cells (AEMFCs) have been regarded as a promising low-cost alternative to proton exchange membrane fuel cells (PEMFCs) due to their potential to utilize platinum group metal (PGM) free catalysts and their recently demonstrated improvement in power density. However, the development of highly active and stable PGM-free electrocatalysts for the hydrogen oxidation reaction (HOR) in alkaline solutions remains a significant challenge. In this study, reactive spray deposition technology (RSDT) is used to fabricate a set of Ni/CeO2/C catalysts, and their activity toward the HOR is investigated as a function of the nanoparticle size. The structural and morphological characterization of as synthesized Ni/CeO2/C catalysts confirms that the RSDT is capable of precise control of the nanoparticle size by adjusting the deposition parameters. The electrochemical rotating disk electrode study shows that the Ni/CeO2/C catalyst with an average particle size distribution of 3 nm has the highest mass activity of 14.8 A gNi(-1), which is among the highest values reported in the literature for Ni-based catalysts. Moreover, the post-test characterization, performed after the accelerated stress test (AST) measurements, reveals that both the catalyst's corrosion and particle size increase are the main contributors to the mass activity loss. The measured electrocatalytic performance confirms the feasibility of the RSDT fabricated Ni/CeO2/C nanoparticles as an efficient PGM-free HOR catalyst for application in AMEFCs, with additional development required to improve their durability. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.