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Noble metal

About: Noble metal is a research topic. Over the lifetime, 15113 publications have been published within this topic receiving 337947 citations.


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TL;DR: In this article, the authors discuss two different membrane reactor concepts which both rely on supported palladium, on the one hand as a permselective membrane material, and on the other hand as base component of a membrane-type hydrogenation catalyst.
Abstract: Membrane reactors applied to catalytic reactions are currently being studied in many places world-wide. Significant developments in membrane science and the vision of process intensification by multifunctional reactors have stimulated a lot of academic and industrial research, which is impressively demonstrated by more than 100 scientific papers on catalytic membrane reactors being published per year. Palladium as a noble metal with exceptional hydrogen permeation properties and, at the same time, broad applicability as a catalyst, first of all for hydrogenation, is part of many of these developments. This paper discusses two different membrane reactor concepts which both rely on supported palladium, on the one hand as a permselective membrane material, and on the other hand as base component of a membrane-type hydrogenation catalyst. Dense palladium composite membranes can be used for hydrogen separation from packed-bed catalysts in gas-phase hydrocarbon dehydrogenation reactions. Mesoporous membranes containing dispersed bimetallic Pd/X-clusters can be employed as so-called catalytic diffusers for liquid-phase hydrogenation, e.g. of nitrate and nitrite in water. The principles of both concepts are introduced, recently obtained experimental data are evaluated in connection with literature results, and the perspectives for further development are highlighted.

467 citations

Journal ArticleDOI
TL;DR: In this article, the preparation, characterization, and application of selected perovskite oxides such as SrTiO 3, KTaO 3, NaTaO3, KNbO3, and NaNbO 3 in photocatalysis are described.
Abstract: Perovskite-type oxides are a class of compounds with the general formula ABO 3 . They are a very important family of materials and exhibit properties suitable for numerous applications. In this review, the preparation, characterization, and application of selected perovskite oxides such as SrTiO 3 , KTaO 3 , NaTaO 3 , KNbO 3 , and NaNbO 3 in photocatalysis are described. In addition, various strategies for enhancing their photocatalytic activities are discussed, including doping with metals and nonmetals (Cr, Ni, Mn, Pb, Bi, N, Br, S, C, and F), modification with noble metal (Au, Ag, Pt, Pd, Ph, Ru) nanoparticles, and doping with rare earth elements (La). Moreover, the review summarizes the influence of different morphologies and surface properties on the photoactivity of the materials.

464 citations

Journal ArticleDOI
TL;DR: A review of surface plasmon resonance-mediated photocatalysis can be found in this article, where the authors highlight diverse applications of plasmoric photocatalysts in mineralization of organic pollutants, organic synthesis and water splitting.
Abstract: Harvesting abundant and renewable sunlight in energy production and environmental remediation is an emerging research topic. Indeed, research on solar-driven heterogeneous photocatalysis based on surface plasmon resonance has seen rapid growth and potentially opens a technologically promising avenue that can benefit the sustainable development of global energy and the environment. This review briefly summarizes recent advances in the synthesis and photocatalytic properties of plasmonic composites (e.g., hybrid structures) formed by noble metal (e.g., gold, silver) nanoparticles dispersed on a variety of substrates that are composed of metal oxides, silver halides, graphene oxide, among others. Brief introduction of surface plasmon resonance and the synthesis of noble metal-based composites are given, followed by highlighting diverse applications of plasmonic photocatalysts in mineralization of organic pollutants, organic synthesis and water splitting. Insights into surface plasmon resonance-mediated photocatalysis not only impact the basic science of heterogeneous photocatalysis, but generate new concepts guiding practical technologies such as wastewater treatment, air purification, selective oxidation reactions, selective reduction reactions, and solar-to-hydrogen energy conversion in an energy efficient and environmentally benign approach. This review ends with a summary and perspectives.

464 citations

Journal ArticleDOI
TL;DR: The discovery and characterization of platinum nitride (PtN), the first binary nitride of the noble metals group, is reported, characterized by a very high Raman-scattering cross-section with easily observed second- and third-order Raman bands.
Abstract: There has been considerable interest in the synthesis of new nitrides because of their technological and fundamental importance. Although numerous metals react with nitrogen there are no known binary nitrides of the noble metals. We report the discovery and characterization of platinum nitride (PtN), the first binary nitride of the noble metals group. This compound can be formed above 45-50 GPa and temperatures exceeding 2,000 K, and is stable after quenching to room pressure and temperature. It is characterized by a very high Raman-scattering cross-section with easily observed second- and third-order Raman bands. Synchrotron X-ray diffraction shows that the new phase is cubic with a remarkably high bulk modulus of 372(+/-5) GPa.

459 citations

Journal ArticleDOI
TL;DR: In this article, an overview of the application of Ir and Ir-containing catalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane water electrolyzer anodes, for both OER and ORR in unit regenerative fuel cell oxygen electrodes is presented.
Abstract: Among noble metal electrocatalysts, only iridium presents high activity for both the oxygen reduction reaction (ORR) in acid medium, in the oxide form, and the oxygen evolution reaction (OER) in acid medium, alloyed with first row transition metals. Indeed, platinum, the best catalyst for the ORR, has poor activity for the OER in any form, and ruthenium, the best catalyst for the OER, in the oxide form, possess poor activity for the ORR in any form. In this work, an overview of the application of Ir and Ir-containing catalysts for the OER in proton-exchange membrane water electrolyzer anodes, for the ORR in proton exchange membrane fuel cell cathodes, and for both OER and ORR in unit regenerative fuel cell oxygen electrodes is presented.

452 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023485
2022986
2021622
2020724
2019896
2018767