Transition metal chalcogenides electronic effect

Trends in the electronic structure of the chalcogenide catalysts have proved to be helpful in the design and understanding of the catalyst clusters. During ORR, the molecular oxygen has been found to react with the cluster as a whole, rather than individual metal atoms.177 The overall number of electrons per cluster unit (NEC) in the valence bond has been shown to have a factor in the activity and stability of the cluster catalysts.177,181 The unsubstituted Chevrel phases have a NEC of 20.177,181 Substituting or intercalating other transition metals into the crystal lattice to make ternary or pseudo-binary Chevrel phases allows for the increase of NEC. It has been found that as the NEC approaches 24, the catalytic activity improves.181 Alonso-Vante compiled the results from his previous studies to show the effect of NEC in... 

Electronic Effects on the Shape of M2X2 Frameworks (X = Naked Chalcogenide Atom, M = Late Transition Metal)... 

Electrolytical production of metals from chalcogenide (in particular, sulphide) compounds was, in fact, the first problem where the researchers faced the essential effect of mixed conductivity in electrochemical practice. Owing to the studies of Velikanov and his team [1-7], we had got the term polyfunctional conductor (PFC) and the main ideas about physico-chemical properties of this object. According to his theory, the electronic conductance of PFC can undergo the semiconductor to metal transformation (Mott transition), which can be detected from the ccaiductivity-temperature dependency. The possibihty had been found for the enhancement of ionic conductivity and, thus, for the improvement of electrochemical behaviour of the melt. It was achieved by means of so-called heteropolar additives— compounds with ionic chemical bond. 

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