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Your search keyword '"Local structure optimization"' showing total 2 results
Start Over Descriptor "Local structure optimization" Topic synergy
2 results on '"Local structure optimization"'

1. Synergistic effects in oxygen evolution activity of mixed iridium-ruthenium pyrochlores

Author

Emiliana Fabbri, Daniel F. Abbott, Petr Krtil, Roman Nebel, Thomas J. Schmidt, Ivano E. Castelli, Spyridon Divanis, Jan Rossmeisl, and Rebecca K. Pittkowski

Subjects
Lanthanide, Materials science, General Chemical Engineering, Inorganic chemistry, Pyrochlore, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, Electrocatalyst, 01 natural sciences, Pyrochlores, Catalysis, Electrochemistry, Iridium, Oxygen evolution, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Ruthenium, Bond length, Synergy, chemistry, engineering, 0210 nano-technology, Electrocatalysis, Local structure optimization
Abstract

Pyrochlore oxides (A2B2O7 ) simultaneously containing iridium and ruthenium in the B-site are promising catalysts for oxygen evolution reaction (OER) in acid media. The catalytic activity of the pyrochlore basedcatalysts is increased by the coexistence of Ir and Ru in the B-site of the pyrochlore structure. Lanthanide(Yb, Gd, or Nd) stabilized mixed pyrochlores with a fraction of Ru in the B-site of x Ru = 0.2, 0.4, 0.6, 0.8were synthesized by the spray-freeze freeze-dry approach. All prepared mixed pyrochlore catalysts aresurpassing the OER activity of the corresponding iridium and ruthenium analogues featuring no cationmixing as well as that of the benchmark IrO2 catalyst. The synergy of Ir and Ru in the B-site of thepyrochlore structure suppresses the effect of the A-site cation radius on the OER activity. The observedOER activity scales with the Ir-Ru bond distance which represents the local structure of the preparedmaterials. The most active ytterbium catalyst also shows a significant stability improvement under OERoperando conditions over the benchmark IrO2&nbsp

Published
2021
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2. Synergistic effects in oxygen evolution activity of mixed iridium-ruthenium pyrochlores.

Author

Pittkowski, Rebecca K., Abbott, Daniel F., Nebel, Roman, Divanis, Spyridon, Fabbri, Emiliana, Castelli, Ivano E., Schmidt, Thomas J., Rossmeisl, Jan, and Krtil, Petr

Subjects
*OXYGEN evolution reactions, *YTTERBIUM, *CATALYSTS, *CATALYTIC activity, *CHEMICAL bond lengths, *PYROCHLORE
Abstract

Pyrochlore oxides (A 2 B 2 O 7) simultaneously containing iridium and ruthenium in the B-site are promising catalysts for oxygen evolution reaction (OER) in acid media. The catalytic activity of the pyrochlore based catalysts is increased by the coexistence of Ir and Ru in the B-site of the pyrochlore structure. Lanthanide (Yb, Gd, or Nd) stabilized mixed pyrochlores with a fraction of Ru in the B-site of x Ru =0.2, 0.4, 0.6, 0.8 were synthesized by the spray-freeze freeze-dry approach. All prepared mixed pyrochlore catalysts are surpassing the OER activity of the corresponding iridium and ruthenium analogues featuring no cation mixing as well as that of the benchmark IrO 2 catalyst. The synergy of Ir and Ru in the B-site of the pyrochlore structure suppresses the effect of the A-site cation radius on the OER activity. The observed OER activity scales with the Ir-Ru bond distance which represents the local structure of the prepared materials. The most active ytterbium catalyst also shows a significant stability improvement under OER operando conditions over the benchmark IrO 2 Image, graphical abstract [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
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