Efficient Electrochemical Hydrogenation of Unsaturated Organics Using Noble-Metal-Free Pentlandite Catalysts

Abstract

Electrocatalytic hydrogenation reactions (ECH) increasingly emerge as promising methods in the reductive production of base- and fine-chemicals. When driven by renewable energies, it constitutes a sustainable option circumventing the need for gaseous hydrogen, high pressure conditions as well as stoichiometric reducing agents which are associated with surplus waste formation. Furthermore, ECH processes can be operated under mild conditions close to room temperature and using green solvents such as water as proton source. Beyond these substantial advantages, an ideal ECH-process requires readily available, cheap and durable electrocatalysts capable of preplacing predominant noble metals to become industrially competitive. Along this line, much can be learned from natural enzymatic systems handling hydrogen. Inspired by the active sites of hydrogenases, which feature abundant transition metals in a sulfidic environment, we employed highly conductive 3d-metal chalcogenides of pentlandite type as highly efficient and cheap electrocatalysts for the ECH of unsaturated organic chemicals. Based on this inspiring compound class we demonstrate the relevant parameters to suppress the formation of parasitic hydrogen in favor for hydrogenations. Additionally, we outline the necessary interplay of material science as well as reactor engineering all the way from an initially promising catalytic material to a scalable sustainable electrochemical cell with industrial potential. Figure 1