Modifying the interfaces of materials alters their electrocatalytic activity through inner-sphere active site control and by altering outer-sphere active site-substrate interactions. To leverage interfacial chemistry in the design of heterogeneous catalysts, we are developing solution-phase methods for the post-synthetic modification of colloidal nanostructures. In this talk, ligand exchange, surface etching, and covalent modification will be presented as complementary methods for altering the catalytic activity of colloidal transition metal phosphide electrocatalysts. We have shown that by covalently functionalizing Ni2P nanocrystals with aryl-groups that span a range of Hammett parameters, we modulate the Ni and P core-electron binding energies and nanocrystal work function. Covalently functionalizing Ni2P improves HER activity and stability, which is corroborated by DFT calculations of H adsorption energies on the Ni3 hollow site. We have built upon this work with electrochemical characterization, physical and electronic structure analysis, and computational studies to elucidate interfacial dynamics in electrocatalytic reactions. Together with stoichiometric probes of inner-sphere reactivity, these data serve to reveal mechanistic details of catalysis in these systems.

Interfacial chemistry as an enabling tool in the development of transition metal phosphide electrocatalysts

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.