Publication date: 15th December 2014
Water electrolysis, combined with renewable electric power generation technologies, is expected to emerge as a low-emission method for storing excess electricity or for producing hydrogen fuel as part of a solar refinery.1-3 Acid Polymer Electrolyte Membrane (PEM) electrolyzers show advantages compared to alkaline electrolyzers in terms of compact system design, operating at high current densities with high voltage efficiency, and providing high gas purity.4 However, acidic environment in PEM electrolyzers requires noble metal catalysts, e.g. RuOx, IrOx for the anodic oxygen evolution reaction (OER).5,6 IrOx appears as a catalyst of choice compromising activity and stability.2 However, the scarce nature of Ir requires significant reduction of Ir loading, which is why novel strategies are critically needed to further reduce the amount of Ir in OER catalysts.
Herein, a family of dealloyed metal–oxide hybrid (M1M2@M1Ox) core@shell nanoparticles immobilized on high surface area (oxide) support is demonstrated to provide substantial advances toward more efficient, stable and less expensive electrocatalytic water splitting. IrNi@IrOx nanoparticles were synthesized from IrNix precursor alloys through selective surface Ni dealloying and controlled surface oxidation of Ir.7,8 Detailed depth-resolved insight into chemical structure, composition, morphology, and oxidation state was obtained using XRD, STEM-EDX, XPS, which confirmed our structural hypotheses. A 3-fold catalytic activity enhancement for the electrochemical OER over Ir benchmark catalyst was observed for the core-shell catalysts on a noble metal mass basis. This study documents the successful use of synthetic dealloying for the preparation of oxide supported core-shell catalysts. The concept is quite general, can be applied to other noble metal nanoparticles, and points out a path forward to nanostructured proton-exchange-electrolyzer electrodes with dramatically reduced noble metal content.
References
(1) Chemical Energy Storage Schloegl, R., Ed.; De Gruyter Berlin, 2013.
(2) Reier, T.; Oezaslan, M.; Strasser, P. ACS Catalysis 2012, 2, 1765.
(3) Dau, H.; Limberg, C.; Reier, T.; Risch, M.; Roggan, S.; Strasser, P. ChemCatChem 2010, 2, 724.
(4) Carmo, M.; Fritz, D. L.; Mergel, J.; Stolten, D. Int. J. Hydrog. Energy 2013, 38, 4901.
(5) Millet, P.; Mbemba, N.; Grigoriev, S. A.; Fateev, V. N.; Aukauloo, A.; Etiévant, C. Int. J. Hydrog. Energy 2011, 36, 4134.
(6) Reier, T.; Teschner, D.; Lunkenbein, T.; Bergmann, A.; Selve, S.; Kraehnert, R.; Schlögl, R.; Strasser, P. J. Electrochem. Soc. 2014, 161, F876.
(7) Nong, H. N.; Gan, L.; Willinger, E.; Teschner, D.; Strasser, P. Chemical Science 2014, 5, 2955.
(8) Nong, H. N.; Oh, H. S; Reier, T.; Willinger, E; Willinger, M. G.; Petkov, V.; Teschner, D; Strasser, P. Angewandte Chemie 2014.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.