Atomic-scale alloys as energy- and cost-efficient catalysts for fuels and chemicals production

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Understanding the molecular-scale adsorption and dissociation behavior of a number of small molecules on catalytically relevant surfaces is crucial for the design of better working catalysts. More efficient, low-cost processes for the production of fuels and chemicals may be developed as a result. Professors Maria Flytzani-Stephanopoulos, Georgios Kyriakou and Charles Sykes form a team at Tufts University, Medford, MA which is receiving an award to utilize their expertise in heterogeneous catalysis and surface science to identify the factors that lead to enhanced catalytic activity and high selectivity of single-atom alloys, particularly aimed at small molecule activations. Their aim is to develop materials and methodologies that will enable wide ranging academic, technical and industrial applications of these catalysts for heterogeneous hydrogenations. The approach is to use a minority metal component such as Pd present as isolated atoms in another metal like Cu, such that the former induces different catalytic properties on the latter. In this example, the Pd atoms can serve to dissociate H2 molecules, and spill over atomic hydrogen to the host metal. Hence the Pd atoms serve as conduits of H atoms to the Cu surface which can now facilitate hydrogenation reactions with gaseous H2, reactions which have been impossible in the previous literature. This novel catalyst system not only reduces the higher temperatures typically required to activate H2 on Cu catalysts and hence reduces waste heat in products but also allows for more selective hydrogenations to proceed at lower temperatures without decomposition observed on the pure metals. In addition to these benefits, alloy particles in which the expensive, active element is atomically dispersed should dramatically reduce the cost of the catalyst materials.The interdisciplinary nature of the project will clearly impact the education of graduate students and postgraduate fellows at Tufts. Extensive training of young researchers at Brookhaven National Laboratory is planned in the project. A significant number of women students comprise the PI and co-PIs groups, and they will participate in some aspects of the project, while the Tufts summer scholars program for undergraduates will be used to recruit other under- represented groups. To increase dissemination, existing websites of the Nano Catalysis and Energy lab and the Surface Science Sykes lab will add video clips and relevant information material on this project to promote this work both as an educational resource and a recruiting tool.