(351d) Electrocatalytic Water Splitting at Ultrathin (Oxy)Hydroxide Films/Precious Metal Interfaces

Design of catalysts with simultaneously enhanced activity, stability and material efficiency for the electrochemical water splitting is of paramount importance for the next generation of alkaline electrochemical devices. Ultrathin (oxy)hydroxide films on precious metal substrates possess impressive activities for these reactions, but the filmsâ?? structure and stability are unknown, and the catalytic mechanism is still unclear. Because of the limited resolution of many in-situ characterization techniques at complex liquid/solid interfaces, first principles-based modeling is strongly positioned to provide atomistic insights into the activity and stability of these fascinating systems.

In this talk, we will first introduce the methodologies we have recently developed towards highly accurate prediction of Pourbaix diagram of transition metal (oxy)hydroxides. Next, using monolayer Ni (oxy)hydroxide films as an example, we will describe a simple scheme to study the structures and the stability of these films on precious metal surfaces. We will show how the ultrathin films can be dramatically stabilized with respect to the corresponding bulk analogues. Next, using hydrogen evolution reaction as an example, we will demonstrate how these techniques can be applied to understand the steady state, the active phases, and the catalytic mechanism of bi-functional interfaces. We will then demonstrate the extension of the present understanding to real world catalysts, i.e. precious metal nanoparticles supported on ultrathin transition metal (oxy)hydroxide films. Finally, we will show this understanding can be used to design new bi-functional catalysts with improved performances.

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