4lessCH4 · Rational Design of Ceria-Supported Non-Noble Metal Nanoalloys as Catalysts for the Selective Direct Conversion of Methane to Methanol

Methane (CH4) is a potent greenhouse gas that can come from many sources, both natural and manmade. The low temperature direct route to converting methane to methanol (CH3OH) a key feedstock for the production of chemicals that can also fuel vehicles or be reformed to produce hydrogen has long been a holy grail. The efficient use of CH4 emissions require catalysts that can activate the first C-H bond while suppressing complete dehydrogenation and avoiding CO/CO2 formation. The potential benefit of finding non-expensive and efficient catalysts for directly converting methane to methanol (DMTM), using only molecular oxygen, and perhaps water, is significant and new catalysts are being sought. This project aims to the rational design of such catalysts based on non-noble metal nanoalloys/reducible oxide systems. There are key challenges to be addressed, namely, to improve reactants activation, to obtain an understanding of the reaction mechanism and to improve selectivity. Real powder catalysts are too complex to enable us to disentagle the effect of the nature of the metallic phase (composition, structure, nanoparticle size), the role of the oxidic support and of metal-support interactions, and the role of alloying and water in controlling selectivity. The strategy here consists of creating and investigating model systems, which include essential parts of the real ones, but can still be studied at the atomic level using state-of-the-art computational methodology in chemistry. Calculations will be performed in close collaboration with experimental work employing well-defined model systems as well as powders. The synergistic power of theory and experiment is crucial to design new or improved catalysts. Theory will not only be used to explain experimental data, but also for pre-screening the behavior of catalysts. The goal is to develop basic principles for the rational design and optimization of nano-structured catalysts for mitigating greenhouse gases.