Scanning Electrochemical Microscopy of Single-Crystal Hydrogen Electrocatalysis

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Shigeru Amemiya and his group at the University of Pittsburgh are developing new electrochemical methods that allow for the identification of reactive intermediates and likely reaction pathways for hydrogen electrocatalysis. This project focuses on gaining an advanced understanding of hydrogen electrocatalysis, which is crucial for the efficient production and utilization of sustainable and clean hydrogen fuel and also for many important fields of electrochemical science and technology. Reliable identification of the molecular mechanism of hydrogen electrocatalysis is urgently demanded not only to understand the superior electrocatalytic activity of platinum-group metals but also to design alternative superior electrocatalysts based on inexpensive and earth abundant elements. Students from underrepresented groups will experience interdisciplinary training by participating in the development of advanced electrochemical instruments for the proposed research and in the implementation of the sophisticated computational simulation of electrocatalysis for an undergraduate laboratory. This project is focused on the quantitative study of both hydrogen evolution and oxidation reactions for the resolution of the intermingled pathways of these two-step two-electron reactions. New nanoelectrochemical methods being developed in the Amemiya laboratory will provide an opportunity to measure the adsorption energy of hydrogen atoms as well as establish the electrochemical identity of surface intermediates. Specifically, Professor Amemiya and his research group are developing and applying transient nanogap voltammetry based on scanning electrochemical microscopy to separately determine the thermodynamic and kinetic parameters of each electron transfer and adsorption step. Reliable reaction parameters can be obtained by employing clean single crystal metals with a well defined arrangement of surface atoms. A volcano plot will be established from the experimentally determined parameters of each involved reaction at both weakly and strongly adsorbing metals and will serve as a valuable guide for the rational design of improved electrocatalysts. 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.