From well-defined clusters to functional materials: molecular Engineering of amorphous molybdenum sulfides for hydrogen evolution Electrocatalysis

Developing precious-metal-free electrocatalysts for the hydrogen evolution reaction (HER) is crucial to establishing H2 produced from renewable energy sources as an alternative energy carrier to fossil fuels. Amorphous molybdenum sulfide-based materials are promising candidates that provide highly active HER electrocatalysts by introducing active sites at both the edge positions and the typically inactive basal planes. Herein, we report an innovative bottom-up synthesis of amorphous molybdenum sulfides using molecular complexes with Mo3S4 and Mo3S7 cluster cores as building entities. The ability to control the precursor of choice has made it viable to enhance the HER activity of these materials. Furthermore, the tunability of the atomic composition of the molecular cluster precursors allows the modification of the derived materials with atomic-scale precision, enabling us to track the synthesis mechanism and, in combination with Density Functional Theory (DFT) calculations, to decipher the nature of the HER active sites

Molecularly engineering Defective Basal Planes in Molybdenum Sulfide for the direct synthesis of Benzimidazoles by Reductive Coupling of Dinitroarenes with Aldehydes

Developing more sustainable catalytic processes for preparing N-heterocyclic compounds in a less costly, compact, and greener manner from cheap and readily available reagents is highly desirable in modern synthetic chemistry. Herein, we report a straightforward synthesis of benzimidazoles by reductive coupling of o-dinitroarenes with aldehydes in the presence of molecular hydrogen. An innovative molecular cluster-based synthetic strategy that employs Mo3S4 complexes as precursors have been used to engineer a sulfur-deficient molybdenum disulfide (MoS2)-type material displaying structural defects on both the naturally occurring edge positions and along the typically inactive basal planes. By applying this catalyst, a broad range of functionalized 2-substituted benzimidazoles, including bioactive compounds, can be selectively synthesized by such a direct hydrogenative coupling protocol even in the presence of hydrogenation-sensitive functional groups, such as double and triple carbon–carbon bonds, nitrile and ester groups, and halogens as well as diverse types of heteroarenes

Multifunctional Catalysis of Nanosheet Defective Molybdenum Sulfide Basal Planes for Tandem Reactions Involving Alcohols and Molecular Hydrogen

Establishing tandem catalytic synthetic strategies based on the use of readily available, stable, and renewable feedstocks is of great significant for the sustainable advancement of chemical-related industries. The key to success largely relies on applying efficient multifunctional catalysts that allow carrying out one-pot single-step synthesis. In this work, we have demonstrated that defect-engineered basal planes of a molybdenum sulfide nanomaterial ({Mo3S4}n) offer a multifunctional catalytic platform for chemical process intensification. By applying this catalyst, besides borrowing hydrogen-type processes, herein exemplified for the thioetherification of alcohols, we have also disclosed novel and rare coupling reactions requiring hydrogen activation and alcohol dehydrogenation processes in a one-pot fashion. More specifically, oxidized nucleophiles, such as o-dinitroarenes and dinitrophenyl disulfides, are reacted with alcohols in the presence of H2 to yield respectively benzimidazoles and benzothiazoles. The uncommon catalytic reactivity of {Mo3S4}n arises from the presence of coordinatively unsaturated molybdenum and sulfide species, which work as Lewis acid and Lewis basic sites, respectively. As suggested by in situ infrared (IR) spectroscopy investigations, the alcohol dehydrogenation involves the participation of both types of active sites while the H2 dissociation takes place on coordinatively unsaturated sulfide species.This work has been supported by the Gen-T Plan of the Generalitat Valenciana through the programs “Subvencions a l’Excel·lència Científica de Júniors Investigadors” (SEJI/2020/018) and “Investigadors Doctors d’Exel·lència” (CIDEXG/2022/22). Financial support by the Severo Ochoa Center of Excellence program (CEX2021-001230-S) is gratefully acknowledged. S.M. thanks DGA/fondos FEDER (construyendo Europa desde Aragón) for funding the research group Platón (E31_20R). M.R. acknowledges the Vice-Rectorate for Research, Innovation and Transfer of the Universitat Politècnica de València (UPV) for a pre-doctoral fellowship. F.D. thanks the ERASMUS+ program. The authors also thank the Electron Microscopy Service of the UPV for TEM and STEM facilities and Dr. G. Antorrena for technical support in XPS studies