Bisthiosemicarbazone Electrocatalysts for the Hydrogen Evolution Reaction: Influence of Metal Ion on Activity and Mechanism
报告简介：Rising international energy demands, coupled with growing concerns of repercussion from global climate change,have ignited considerable interest in the development of carbon-free and carbon neutral energy systems. Hydrogen is apromising component of these systems as a light weight, energy dense carrier. Hydrogen evolution reactions (HERs),which involve a two-electron reduction of protons, can be used to store energy in H,, with subsequent energy releasethrough hydrogen oxidation reactions (HORs). Consequently, there has been significant research into the developmentof inexpensive, abundant homogeneous and heterogeneous materials that serve as electrocatalysts for the production ofH, Platinum is an excellent catalyst for HER and HOR, yet its scarcity and high costs limit practical large scale application,leading to the pursuit of sustainable alternates that employ abundant first-row transition metals. The most promising ofthese systems proceed with the participation of a crucial metal-hydride intermediates While this approach hasled to substantial advances, sustainable candidates are limited to economically viable first-row transition metalscomplexes capable of stabilizing metal-hydrides An alternate approach are HER catalysts that functionvia ligand-centered processes by employing redox-active ligands. We developed a series of new HER catalysts basedon the redox+ active bi-thiosemicarbaz ligand H,L' (=diacetyl-bis(N4methy3th The HERactivity ofNiL', CuL', and ZnL' have been evaluated through a series of electrochemical investigations to determine theimpact of the metal ion. Next, a series of experimental and computational investigations were performed to evaluate theinfluence of the metal ion on the HER mechanisms Interestingly, while each complex acts as an HER catalysts, each cat-alyst operates via a different reaction mechanism that this dictated by the electron count and geometric preferences ofeach metal ion. The results demonstrate the versatility of bis-thiosemicarbazon ligands for catalytic activity and offernew routes for the development of HER catalysts.