Collaborative Research: Tailoring the Catalytic Properties of Pd Single Atoms Using Covalent Organic Frameworks

About This Grant

Catalysts are used widely in industrial processes to improve energy efficiency and direct chemical reactions toward desired products. The project examines novel catalyst designs for an important class of industrial reactions – selective hydrogenations - used for many applications such as the production of plastics, fragrances and pharmaceuticals. The precious metal palladium (Pd) is widely used for selective hydrogenation reactions. The project aims to maximize utilization of the precious metal in the form of isolated atoms, and tailor their properties by anchoring them to covalent organic frameworks (COFs), which are highly crystalline porous materials with specific binding sites for the metal atoms. The investigators will synthesize and characterize the catalysts using a suite of laboratory- and synchrotron-based characterization techniques. The catalysts will be tested for the selective hydrogenation of acetylene to ethylene to determine how the binding sites affect the activity and selectivity of the Pd atoms. Beyond the research, the project involves education of graduate and undergraduate students with cross-training of researchers between the two institutions and focused efforts to increase participation of underrepresented groups in catalysis science. The project aims to tailor the properties of Pd single atoms using covalent organic frameworks (COF) as the support/ligand, and thus circumvent trade-offs between activity and selectivity associated with traditional metal oxide supported nanoparticle catalysts for the semi-hydrogenation of ethylene. Areas of focus include 1) the effects of the COF binding sites and secondary ligands on the Pd electronic properties, 2) hydrogen activation, 3) binding with adsorbates and 4) catalyst activity/selectivity. Those thrusts will be accomplished through precise catalyst synthesis, advanced characterization techniques (in-situ/operando X-ray spectroscopies, microcalorimetry) and detailed kinetic measurements. The project will identify the possibilities and limitations for designing catalysts based on Pd metal single atoms. The interdisciplinary nature of this research, and the integration of research and education plans will lead to a cadre of students obtaining a unique educational experience on heterogeneous catalysis and advanced lab- and synchrotron-based characterization techniques. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.