Minireview on the Evolution of Tetrathiometallate Salts as Protean Building Blocks of Catalysts and Materials for the Energy Transition: Recent Advances and Future Perspectives

Transition-metal sulfides are prodigiously studied materials with a 100-year history in the development of catalysts and hierarchal structures found throughout the energy industry. A constructive subset of these compounds are the Group VI tetrathiometallates of the form [MS4](2-)(where M = Mo or W) that are used as building blocks in a variety of complex chalcogenide-based materials. Originally used as structural motifs for building nitrogenase model clusters, these salts have since been incorporated into commercially relevant products, such as pharmaceuticals, unsupported catalysts, porous networks for separations, and solar cell components. Tetrathiometallate anions are advantageous as metal sulfide constructs, because of their simple synthesis and solubility in aqueous or polar hydrocarbon solvents made tunable by selection of the proper cation. This minireview will provide historical context of [MS4](2-) salts used in the preparation of conventional sulfide materials and discuss their relevance to areas related to the energy transition. Examples of the latter include their use as catalysts for crude oil conversion, as porous structures for gas separations or contaminant removal, and in electrodes for photoelectrochemical devices.