A longstanding challenge in the field of energy conversion is the development of earth abundant water oxidation and proton reduction catalysts catalysts whose performance can rival or exceed that of Ir and Pt based materials. Amorphous catalysts offer some of the highest performance to date, yet are poorly understoon. Key to the continual development of next-generation improved catalysts is the detailed elucidation of the performance behind current state-of-the-art materials. Within this context, in-situ spectroscopic techniques are invaluable towards revealing the functional species within the catalyst as well as the catalytically active sites. Herein, I describe our efforts in the study of amorphous cobalt sulfide and cobalt phosphide catalysts that can perform the hydrogen evolution (HER) and oxygen evolution (OER) reactions with exceedingly high efficiency. Utilizing a combination of electroanalytical, Raman and X-ray absorption spectroscopic, and quartz-crystal microbalance gravimetric techniques, we discover that the active state of the aformentioned catalysts are meta-stable molecular clusters formed under highly reducing or oxidizing potentials. Finally, I discuss the structure-function relationships behind the amorphous catalysts that these in-situ measurements brought forth and how the results here can be used to guide the future developments.

Expanding the scope of in situ techniques to probe amorphous electrocatalysts

254th National Meeting (2017)

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