Selective ammoxidation of propane over Sb-Nb-V oxide catalysts with α-Sb2O4 and rutile type structure

Molecular Precursor Route to Bulk and Silica-Supported Nb2Mo3O14 Using Water-Soluble Oxo-oxalato Complexes

“…In recent years, multimetallic Nb-containing oxides have generated considerable interest in many fields because of their attractive physical or chemical properties. One of the most important features of these materials is their promising catalytic behavior in several highly challenging industrial processes, like alkane oxidation or ammoxidation. , Pure niobium pentoxide itself is a very selective catalyst for propane oxidative dehydrogenation (ODH) even though its catalytic activity is only moderate. − In recent years, it has been shown that associating niobium with elements such as vanadium, molybdenum, or antimony could considerably improve the catalytic activity while maintaining a high selectivity in such reactions. ,− Bulk or supported oxides from multicomponent systems such as Nb−V−Mo, ,, Nb−V−Mo−Sb, , and Nb(−V)−Mo−Te 7,8,15-18 are still under thorough investigation and huge efforts have been made to optimize their formulations or preparation methods to improve their catalytic performance. These catalysts are in general multiphasic, and the constituent phases are often poorly defined or even unknown.…”

Synthesis, characterization and evaluation as catalysts for propane ammoxidation of VMoSbO systems with rutile-type structure

“…Rutile-based systems, including V/Sb/(W, Al)/O [1][2][3][4][5][6], Fe/V/Sb/O [7,8], Sn/V/Sb/O [9], Cr/Sb/O [10], Ga/Sb/O [11] and V/Nb/Sb/O [12], are known to be efficient catalysts for the ammoxidation of propane to acrylonitrile. The particular properties of these systems arise from the following chemical-physical features: (i) formation of mixed oxides in which the components essential for the activation of paraffins (i.e., V, but also Fe, Ga or Cr) and those which are active in the O/N insertion on the allylic-type intermediate, belong to the same structure and can effectively co-operate in the transformation of the alkane, and (ii) ability to disperse antimony oxide on its surface, in the form of a supra-surface layer above quasi-VSbO 4 [13], which also plays an important role in the reaction mechanism.…”