The universal character of the Mars and Van Krevelen mechanism

This review deals with the mechanism that is arbitrarily called below the Mars and Van Krevelen (MvK) mechanism. The characteristic feature of this mechanism is that some products of the reaction leave the solid catalysts' surface with one or more constituents of the catalysts' lattice. First in this review, the position of this mechanism amongst other ways of catalytic activation will be defined. Then, the experimental evidence for this mechanism will be presented. Some less common reactions running with this mechanism will be discussed in more detail, among them the deoxygenation of nitrocompounds and carboxylic acids. The participation of the lattice components (O, S, Cl, H) in the formation of products leads to a relation of the catalytic activity with the thermodynamic parameters characterizing the catalysts lattice. A proper use of such quantified relation will be also discussed. (C) 2000 Published by Elsevier Science B.V.