Collaborative Research: Tuning Hydrogen Mobility on Au/Spinel Catalysts to Develop the Isotopic Kinetic Resolution of H2 and D2

With funding from the Chemical Catalysis program in the Division of Chemistry, Professor Chandler at Penn State University and Professor Grabow at the University of Houston will collaborate to build the scientific foundations for a new H-D separation technique termed 'isotopic kinetic resolution' (IKR). Due to the added mass of the neutron, deuterium tends to react more slowly in H-atom transfer reactions. The research team will conduct an experimental and computational study of hydrogen mobility and diffusion across aluminum oxide surfaces to understand the important factors in controlling the speed of H- and D- atom transport. This will include developing methods to control the spacing between catalytic H2/D2 activation sites and H/D reaction sites on the oxide surface. The team will then screen spinel oxides, a class of transition doped aluminum oxide materials with wide ranging electronic properties, for their H/D-atom transport properties using several computational and machine-learning techniques. Promising candidate oxides will be synthesized and their H-mobility fully evaluated and compared to predictions to begin developing the IKR. Both principal investigators will recruit graduate and undergraduate students from underrepresented minority (URM) groups. The principal investigators are also accomplished undergraduate mentors and will continue to involve UG students in this project.

This collaborative research project will be focused on experimental and computational studies of hydrogen mobility and diffusion across tunable spinel oxide surfaces, with the aim of developing the novel concept of isotopic kinetic resolution (IKR). IKR is a kinetic tool capable of separating H/D isotopes by leveraging the large kinetic isotope effect for H/D transport on metal oxides. Further development of this technique may also lead to new design strategies for selective hydrogenation catalysts. To establish this new tool, the team will use density functional theory calculations combined with machine-learning techniques to screen for spinel oxides with suitable electronic structures. Promising candidates will be synthesized and their H-mobility evaluated through careful kinetic measurements and kinetic Monte Carlo simulations. Significant effort will be dedicated to the development of synthetic methods that will allow the research team to direct the spacing between primary reaction centers, where H2 is activated, and secondary reaction centers, where hydrogenation occurs.

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.