Unique Nanostructure Revealed in New OER Electrocatalyst
Haber, J. A., Anzenburg, E., Yano, J., Kisielowski, C. & Gregoire, J. M. Multiphase Nanostructure of a Quinary Metal Oxide Electrocatalyst Reveals a New Direction for OER Electrocatalyst Design. Advanced Energy Materials, DOI: 10.1002/aenm.201402307 (2015).
JCAP discovered a new electrocatalyst for the oxygen evolution reaction (OER) containing 5 elements: Ni, Fe, Co, Ce, and O. Further detailed investigation revealed that the catalyst is comprised of transition metal oxide and ceria nanoparticles that are intimately mixed with atomically sharp interfaces, a unique nanostructure for OER catalysts.
Significance & impact
At low OER overpotential required for efficient solar fuel generation, the addition of Ce to transition metal oxides greatly enhances the catalytic rate. The catalyst structure was revealed through state-of-the-art X-ray spectroscopy and electron microscopy techniques. The discovered nano-particle composition morphology opens a new scientific approach for catalyst design.
Left: The eight compositions are shown in quaternary compositional space. All compositions (except the black point) are in the Ni–Fe–Co ternary triangle (shaded gray), and arrows connect the best one Transition Metal oxides (TM), two TM, three TM, and three TM + Ce compositions. Right: Ni0.3Fe0.07Co0.2Ce0.43Ox catalyst; elemental maps of the catalyst produced by EDS with a probe size of 2–3 Å.