(Invited) Electrochemical Conversion Using 2D Transition Metal Dichalcogenides

Abstract

We use 2D transition metal dichalcogenide (TMDC) catalysts to facilitate the nitrogen (N2) reduction to ammonia (NH3) or proton reduction to hydrogen (H2) via dark electrocatalysis. TMDCs are an important class of materials because they are 2D materials, where their quantum confined properties are easily manipulated for various applications. Transition metal-based catalysts offer a unique opportunity to exploit the d electrons and orbitals for N2 activation, where we specifically compare theoretically and experimentally MoS2, TiS2, and VS2. In addition, the 2D TMDC catalysts are highly tunable 2D catalysts, where the band energetics, surface functionalization, defects, and phase can be tuned to control the N2 and proton reactivity. We use indophenol and 1H NMR with isotope labeling to identify and quantify NH3 from the catalytic reaction; moreover, we use density functional theory to add insight into the 2D TMDC active site and reaction pathway. Through various attempts and iterations, we have many lessons learned about experimental and theoretical setup that will be communicated.