The following emblematic examples of the complex phenomenology occurring at the gas-solid interface in gas-phase selective oxidation reactions are reported: (a) Surface transformations occurring in vanadyl pyrophosphate - the catalyst for n-butane oxidation to maleic anhydride - depending on both reaction conditions and catalyst composition, and the role of P-containing compounds which are added as gas-phase promoters to retard irreversible deactivation. (b) Dynamic phenomena occurring at the surface of supported vanadium oxide-based catalysts, in which the presence of steam and/or S-containing compounds may limit sintering phenomena in the active species and deactivation. (c) In metal oxyhalides for the oxyhalogenation of unsaturated hydrocarbons, the formation of low-melting eutectics under reducing conditions can lead to the sticking of catalyst particles and irreversible catalyst deactivation.
F. Cavani (2009). Deactivation in oxidation catalysis: inevitabile events, reversibile phenomena and beneficial in-situ rejuvenations. DELFT (NL) : Delft University of Technology Technologisch Insti.
Deactivation in oxidation catalysis: inevitabile events, reversibile phenomena and beneficial in-situ rejuvenations
CAVANI, FABRIZIO
2009
Abstract
The following emblematic examples of the complex phenomenology occurring at the gas-solid interface in gas-phase selective oxidation reactions are reported: (a) Surface transformations occurring in vanadyl pyrophosphate - the catalyst for n-butane oxidation to maleic anhydride - depending on both reaction conditions and catalyst composition, and the role of P-containing compounds which are added as gas-phase promoters to retard irreversible deactivation. (b) Dynamic phenomena occurring at the surface of supported vanadium oxide-based catalysts, in which the presence of steam and/or S-containing compounds may limit sintering phenomena in the active species and deactivation. (c) In metal oxyhalides for the oxyhalogenation of unsaturated hydrocarbons, the formation of low-melting eutectics under reducing conditions can lead to the sticking of catalyst particles and irreversible catalyst deactivation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
