Concerted mechanisms in heterogeneous catalysis by sulfides

Abstract

This paper summarizes new evidences concerning the performance of concerted mechanisms in heterogeneous catalysis by sulfides. Several aspects are discussed: main regularities of thiophene and tetrahydrothiophene hydrogenolysis mediated by wellcharacterized sulfide catalysts of different composition; electronic structure of the metals sulfide catalysts of different composition; electronic structure of the metals entering into composition of the active component of sulfide catalysts; mechanism of the active center formation due to the oxidative addition of dihydrogen to the active Ni (Co) metals and occlusion, of hydrogen atoms into the MoS 2 matrix; mechanism of the homolytic hydrogen activation on the terminal sulfur atoms enframed an electroneutral macromolecule of the active component; synchronous interaction of the reactive molecules in the coordination sphere of the bimetallic active centers-protons and electrons transfer; use of energy released in exothermic reaction steps in the catalytic cycle. The catalytic transformation over sulfide HDS catalysts is believed to belong to acid-base catalysis.