idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instanz:
Teilen: 
20.02.2019 14:56

Researchers at Jacobs University Bremen discover a new class of heterogeneous catalysts

Heiko Lammers Corporate Communications & Public Relations
Jacobs University Bremen gGmbH

    It is stable and recyclable: a team of scientists from Jacobs University led by Ulrich Kortz, Professor of Chemistry, has developed a new class of materials in close cooperation with researchers from the Carl von Ossietzky University of Oldenburg and the Technical University of Munich. The compound based on the precious metal palladium paves the way for the full use of the entire class of discrete polyoxopalladates (POPs) as building blocks for 3D framework materials (MOFs). The project was funded by the German Research Foundation (DFG). The name of the new class of materials: POP-MOF, JUB-1.

    Precious metals such as palladium are probably the most omnipresent catalysts in modern organic synthetic chemistry. In 2010, the Nobel Prize in Chemistry was awarded for such research work (Heck, Negishi, Suzuki). Reactions involving palladium-based catalysts are important tools in various processes of industrial importance, such as the synthesis of agrochemicals, natural products, pharmaceuticals, and high octane gasoline. The reason for such a wide-ranging scope boils down to the unique ability of palladium (either in +2 or 0 oxidation states) to act as an efficient catalyst in various organic reactions. However, the efficacy of such catalytic reactions can be hampered severely by several factors such as (i) instability of the catalyst due to leaching or (ii) poor recyclability and hence recovery of the catalyst. Thus, over the past few decades, researchers from around the world have been working intensely on the development of novel, improved Pd-based catalytic materials.

    In 2008 the research group of Ulrich Kortz, who is an expert in the synthesis of polynuclear metal-oxide clusters (so called polyoxometalates or POMs), made a pivotal discovery with the synthesis of the first discrete noble metal-based POM in aqueous medium. This polyoxopalladate (or POP) with the formula [Pd13O8(AsO4)8H6]8- paved the way for a large family (currently ca. 70) of POPs of various size, shape and composition. Catalytic studies using the highly active POPs helps to better understand the mechanism of noble metal-based molecular catalysis. However, it is difficult to recover soluble (homogeneous) catalysts from the reaction products and hence the chemical industry usually prefers insoluble (heterogeneous) catalysts with a large surface area.

    In this context, Prof. Kortz and his co-workers Dr. Saurav Bhattacharya and Dr. Wassim W. Ayass envisaged a strategy wherein they could use externally modified discrete POPs as building blocks for the construction of a rigid and catalytically active framework material, a so-called metal-organic framework (MOF). MOFs are an important class of materials comprising ordered periodic networks of molecular components (metal ions or clusters) that are interconnected in three dimensions by organic groups (linkers), leading to a stable framework structure with accessible cavities or pores. This can be compared to the construction of a traditional timber-framed German house, where the wooden pegs (metal ions or clusters) are held in place by beams (rigid organic linkers) and the resulting rooms would be analogous to the pores of the MOF.
    Utilizing this strategy, Saurav Bhattacharya has now constructed such a molecular house by synthesizing a stable POP-based MOF material (POP-MOF) for the first time. Wassim Ayass assisted him in evaluating its heterogeneous catalytic activity for microwave-assisted Suzuki-Miyaura C-C coupling reactions. The team discovered that the catalyst has good stability and recyclability. The name of the new material (JUB-1) is derived from the location of the invention, Jacobs University Bremen (JUB). Another research team at JUB (Prof. V. Wagner, Physics) as well as research teams of the Carl von Ossietzky University Oldenburg and the Technical University Munich were also involved in the physicochemical characterization of JUB-1.
    The results of the research work have now been published in the renowned Journal of the American Chemical Society.

    For more information:
    https://www.jacobs-university.de
    https://www.facebook.com/jacobs.university
    https://www.youtube.com/user/JacobsUni
    https://twitter.com/jacobs_bremen
    https://www.instagram.com/jacobsuniversity/
    https://www.weibo.com/jacobsuniversity

    Heiko Lammers | Corporate Communications & Public Relations
    h.lammers@jacobs-university.de | Tel.: +49 421 200-4532

    Commercial registry: Amtsgericht Bremen, HRB 18117
    President / Chairman of the Executive Board (Vorsitzender der Geschäftsführung): Prof. Dr. Michael Hülsmann
    Managing Director (Geschäftsführer): Dr. Michael Dubbert
    Chairman of the Board of Governors (Aufsichtsratsvorsitzender): Prof. Dr. Antonio Loprieno


    Wissenschaftliche Ansprechpartner:

    Ulrich Kortz | professor of chemistry
    u.kortz@jacobs-university.de | Tel.: +49 421 200-3235


    Originalpublikation:

    Discovery of Polyoxo-Noble-Metalate-Based Metal-Organic Frameworks
    Bhattacharya, S.; Ayass, W. W.; Taffa, D. H.; Schneemann, A.; Semrau, A. L.; Wannapaiboon, S.; Altmann, P. J.; Pöthig, A.; Nisar, T.; Balster, T.; Burtch, N. C.; Wagner, V.; Fischer, R. A.; Wark, M.; Kortz, U.
    J. Am. Chem. Soc. 2019, DOI: 10.1021/jacs.8b13397 [https://pubs.acs.org/doi/10.1021/jacs.8b13397]


    Bilder

    Ulrich Kortz, Professor of Chemistry at Jacobs University in Bremen, and his colleague Dr. Saurav Bhattacharya with a POM model.
    Ulrich Kortz, Professor of Chemistry at Jacobs University in Bremen, and his colleague Dr. Saurav Bh ...
    Private
    None


    Merkmale dieser Pressemitteilung:
    Journalisten, Lehrer/Schüler, Studierende, Wissenschaftler, jedermann
    Chemie
    überregional
    Forschungsergebnisse, Forschungsprojekte
    Englisch


     

    Ulrich Kortz, Professor of Chemistry at Jacobs University in Bremen, and his colleague Dr. Saurav Bhattacharya with a POM model.


    Zum Download

    x

    Hilfe

    Die Suche / Erweiterte Suche im idw-Archiv
    Verknüpfungen

    Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.

    Klammern

    Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).

    Wortgruppen

    Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.

    Auswahlkriterien

    Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).

    Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).