Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions
| Autor: | Nedeljko V. Krstajić, Miranda Labou, Polycarpos Falaras, Jelena M. Jaksic, Milan M. Jakšić, S. G. Neophytides, Reidar Tunold, Velimir Radmilovic, Ljiljana M. Vračar |
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| Rok vydání: | 2007 |
| Předmět: |
Primary oxide (M-OH)
Hydrogen Inorganic chemistry Oxide Hypo-hyper-d-d-bonding chemistry.chemical_element Proton exchange membrane fuel cell 02 engineering and technology 010402 general chemistry Electrocatalyst 01 natural sciences law.invention Catalysis chemistry.chemical_compound law Synergistic interactive electrocatalysts Magneli phases Materials Chemistry Clark electrode Electrolysis of water Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics SMSI (strong metal-support interaction) 0104 chemical sciences Surfaces Coatings and Films Spillover Reversible H2/Au/TiO2 electrode chemistry Reversible hydrogen electrode Monoatomic network 0210 nano-technology |
| Zdroj: | Surface Science |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/j.susc.2007.02.019 |
| Popis: | Magneli phases [A. Magneli, Acta Chem. Scand. 13 (1959) 5] have been introduced as a unique electron conductive and interactive support for electrocatalysis both in hydrogen (HELR) and oxygen (OELR) electrode reactions in water electrolysis and Low Temperature PEM Fuel Cells (LT PEM FC). The Strong Metal-Support Interaction (SMSI) that imposes the former implies: (i) the hypo–hyper-d-interbonding effect and its catalytic consequences, and (ii) the interactive primary oxide (M-OH) spillover from the hypo-d-oxide support as a dynamic electrocatalytic contribution. The stronger the bonding, the more strained appear d-orbitals, thereby the less strong the intermediate adsorptive strength in the rate determining step (RDS), and consequently, the faster the facilitated catalytic electrode reaction arises. At the same time the primary oxide spillover transferred from the hypo-d-oxide support directly interferes and reacts either individually and directly to contribute to finish the oxygen reduction, or with other interactive species, like CO to contribute to the CO tolerance. In such a respect, the conditions to provide Au to act as the reversible hydrogen electrode have been proved either by its potentiodynamic surface reconstruction in a heavy water solution, or by the nanostructured SMSI Au on anatase titania with characteristic strained d-orbitals in such a hypo–hyper-d-interactive bonding (Au/TiO 2 ). In the same context, some spontaneous tendency towards monoatomic network dispersion of Pt upon Magneli phases makes it possible to produce an advanced interactive supported electrocatalyst for cathodic oxygen reduction (ORR). The strained hypo–hyper-d-interelectronic and inter-d-orbital metal/hypo-d-oxide support bonding relative to the strength of the latter, has been inferred to be the basis of the synergistic electrocatalytic effect both in the HELR and ORR. |
| Databáze: | OpenAIRE |
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