(Graph Presented) Iron-incorporated nickel-based materials show promise as catalysts for the oxygen evolution reaction (OER) half-reaction of water electrolysis. Nickel has also exhibited high catalytic activity for methanol oxidation, particularly when in the form of a bimetallic catalyst. In this work, bimetallic iron-nickel nanoparticles were synthesized using a multistep procedure in water under ambient conditions. When compared to monometallic iron and nickel nanoparticles, Fe-Ni nanoparticles show enhanced catalytic activity for both OER and methanol oxidation under alkaline conditions. At 1 mA/cm2, the overpotential for monometallic iron and nickel nanoparticles was 421 and 476 mV, respectively, while the bimetallic Fe-Ni nanoparticles had a greatly reduced overpotential of 256 mV. At 10 mA/cm2, bimetallic Fe-Ni nanoparticles had an overpotential of 311 mV. Spectroscopy characterization suggests that the primary phase of nickel in Fe-Ni nanoparticles is the more disordered alpha phase of nickel hydroxide.
Bibliographical noteFunding Information:
Funding for this research was provided by the NIST Nanomanufacturing Initiative through the NIST Nanoparticle Manufacturing Program. The authors would like to acknowledge Roy H. Geiss for TEM images of Fe NPs and Ni NPs (Supporting Information, Figure S1). ICP-MS measurements were performed at the Laboratory for Environmental and Geological Studies at the University of Colorado at Boulder. XPS measurements were performed by Rocky Mountain Laboratory, Inc. in Golden, CO. XAFS and HE-XRD measurements were performed in 12-BM and 11-ID-C beamlines at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. N.S. acknowledges National Science Foundation award number DMR-1063150, REU Site: Research Experiences for Undergraduates in Renewable Energy. The authors also acknowledge Army Research Office MURI award W911NF-11-1-0462.
© 2016 American Chemical Society.
- alcohol oxidation
- core-shell nanoparticles
- fuel cell
- nonprecious metal
- oxygen evolution reaction