MXENES AS THERMAL CATALYSTS. EXPLOITING THE IDEAL PROPERTIES OF CHAMELEONIC MATERIALS

Projektbeschreibung

Das Potenzial von MXenen in der thermischen Katalyse erforschen

MXene sind eine Klasse fortgeschrittener Werkstoffe, die wegen ihrer Fähigkeit zur Beschleunigung chemischer Reaktionen mittels Elektrizität oder Licht umfassend untersucht worden sind. Trotz ihrer vielversprechenden Eigenschaften fand ihr Wirkpotenzial als Katalysatoren in wärmegetriebenen Reaktionen (Thermokatalyse) bisher kaum Beachtung. Im Rahmen des ERC-finanzierten Projekts DISCOVERY soll eingehender untersucht werden, wie die einzigartigen Eigenschaften von MXenen, also etwa die Fähigkeit zur Abstimmung ihrer Struktur, Bildung von Multimetallegierungen und starken Interaktion mit Metallen, zu einer besseren Thermokatalyse führen können. Die Forschenden werden Berechnungen der Dichtefunktionaltheorie und KI-Tools verwenden, um das katalytische Verhalten vorherzusagen und somit herkömmliche Versuch-und-Irrtum-Ansätze vermeiden. Eine detaillierte spektroskopische Analyse wird es dem Team ermöglichen, die Funktionsweise von MXenen auf molekularer Ebene zu entschlüsseln.

Ziel

MXenes were discovered in 2011 and, since then, have attracted attention as electro- and photocatalysts. In contrast, the ideal properties of MXenes as thermal catalysts remain almost unexplored, there being a very limited number of studies. The main reasons for this apparent lack of interest are: i) the shift in catalysis from heat as energy to overcome activation barriers to green electricity or sunlight, ii) the limited number of commercial MXenes and iii) the relative novelty of these materials. However, MXenes offer unique compositional range, structural flexibility and material properties that can make them disruptive catalysts. These properties include: i) prediction of the catalytic properties by DFT calculations, ii) possibility of metal alloying resulting in multimetallic MXenes, iii) absence or presence of surface terminal groups of various elements, including OH, -O- and halides, iv) control of lateral size from 2D to 0D forming MXene dots, v) strong metal support interaction making possible single atom catalysis. The aim of DISCOVERY is fill the current gap, applying MXenes to reactions in which their structure appears to be optimal according to the nature of active sites (Ti-OH or V=O) and DFT predictions (strong CO2 adsorption on surface-free MXenes). Specifically DISCOVERY will study two reaction types characteristic of some active sites such as titanol (alkene epoxidation) and vanadyl (CH4 oxidation to CH3OH and oxidative alkane dehydrogenation) or of metal nanoparticles (hydrogenation of CO2 and N2 and CH4 decomposition to H2 and carbon). DISCOVERY will not be a trial and error check of new catalysts, since it will be led be predictive DFT calculations and artificial intelligence tools. Extensive use of XAS (to monitor the changes in the metal elements during the reaction) and vibrational spectroscopy (detection of reaction intermediates) will shed light on the reaction mechanism.