The selective oxidative activation of light alkanes. From supported vanadia to multicomponent bulk V-containing catalysts

Abstract

V-containing materials have been proposed as active and selective catalysts in the selective oxidative transformation of C 2 -C 4 alkanes to the corresponding olefins, oxygenates and nitriles. Although vanadium ions are generally assumed as the active sites in the oxidative activation of short chain alkanes, the coordination, the oxidation state and the environment of V atoms strongly influence both the catalytic activity and the nature of the reaction products. A comparative study on the catalytic behaviour of V-containing catalysts, i.e. metal vanadates, supported vanadium oxides, V-containing microporous/mesoporous materials and multicomponent bulk Mo-V-Te(Sb)-Nb mixed metal oxides, on the alkane oxidation is presented. The influence of the structure (including the V-coordination and V-environment) and the physico-chemical properties (especially redox and acid-base characteristics) of the catalysts on their behaviour in the selective oxidation of paraffins and alkenes is discussed.KEY WORDS: activation of light alkanes by vanadia catalysts; selective oxidative oxidation of light alkanes.

Active Sites for Propane Oxidation: Some Generic Considerations

“…We interpret this as sign of the operation of a complex sequence of elementary steps where some of them are slow rather than of a single difficult reaction followed by a series of only fast consecutive processes. This is in line with the specificity [123] of oxidation catalysts for different products [124][125][126] excluding that different catalyst performing all the same rate-determining step would bring about different product distributions (see also Fig. 4).…”

Nature of dispersed vanadium oxide: influence of the silica support structure and synthesis methods

“…[10][11][12][13] Regarding technical applications, catalytic processes based on the oxidative transformation of alkanes to olefins or oxygenates are still scarce. In industry, there has been an increasing demand for propene over the last years mainly due to its use in polypropylene production.…”

Catalytic behavior of NaV6O15 bronze for partial oxidation of hydrogen sulfide

“…The catalysts will be named as HT-x, where x is referred to the Na/V atomic ratio in the synthesis gel. 5 For comparison, an unpromoted and a Na-promoted V2O5 catalyst have been also prepared. Pure V2O5 has been prepared from ammonium metavanadate by calcinations at 550ºC for 2h.…”

“…Vanadium oxide based materials is an interesting group of catalysts which have been reported as selective in partial oxidation reactions of alkanes, alkenes and aromatic hydrocarbons [1][2][3][4][5] and, more recently, in the partial oxidation of H2S to sulphur [6][7][8][9][10][11][12][13][14].…”