Enhanced electrocatalytic reduction of CO ₂ with ternary Ni-Fe ₄S ₄ and Co-Fe ₄S ₄-based biomimetic chalcogels

Enzymes that catalytically transform small molecules such as CO, formate, or protons are naturally composed of transition metal cluster units bound into a larger superstructure. Artificial biomimetic catalysts are often modeled after the active sites but are typically molecular in nature. We present here a series of fully integrated porous materials containing Fe ₄S ₄ clusters, dubbed "biomimetic chalcogels". We examine the effect of third metal cations on the electrochemical and electrocatalytic properties of the chalcogels. We find that ternary biomimetic chalcogels containing Ni or Co show increased effectiveness in transformations of carbon dioxide and can be thought of as solid-state analogues of NiFe or NiFeS reaction centers in enzymes.