Vanadium oxides supported on amorphous aluminum phosphate: Structural and chemical characterization and catalytic performance in the 2-propanol reaction

Insight into the gas‐phase glycerol dehydration on transition metal modified aluminium phosphates and zeolites

“…The transformation of 2‐propanol takes place preferably by two reactions: dehydration to propene (C 3 H 6 ), mainly on acid sites, and dehydrogenation to propanone (C 3 H 6 O), mainly on basic/redox sites . Furthermore, under certain experimental conditions, such as low temperatures and high partial pressure of 2‐propanol, the formation of diisopropyl ether (C 6 H 14 O), would be favoured also on acid sites.…”

“…On the other hand, the 27 Al NMR of the different phosphates showed a main resonance at approximately +38 ppm, which is typical of tetrahedral aluminium sharing oxygen atoms with four phosphorus tetrahedrals (Al(OP) 4 ). Other small resonances at +14 and –13 ppm are ascribed to Al species partially coordinated with hydroxyl groups in octa‐ and pentahedral coordination, respectively . With the presence of a second metal in the AlPO 4 a slight increase of both components was observed, especially in Al‐CoPO450 and AlFePO450.…”

“…For all the phosphates, the 31 P NMR showed a single peak around –25 ppm, typical of amorphous aluminium phosphates, which can be assigned to P atoms in tetrahedral coordination. Hence, the environments of phosphorus nuclei are mainly P(OAl) 4 …”

Understanding the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate over vanadia/titania

“…The 1-V 2 O 5 /TiO 2 showed charge-transfer bands centred around 280-350 nm, assigned to isolated tetrahedral V 5+ species. 25 As V 2 O 5 loading increased, the absorption bands shifted to higher wavelengths, reflecting the lower-energy transitions of the charge transfer between oxygen and V atoms. 26 This indicates the formation of highly coordinated polymeric vanadium species from isolated tetrahedral monomeric species (cf.…”

Synthesis and comparison of the activities of a catalyst supported on two silicate materials

“…In the field of catalysis, recent studies have used various supports in the search for catalysts with high selectivity and efficient in the epoxidation of olefins, i.e. carbon nanotubes [5] organic polymers [6] and amorphous aluminum phosphate [7]. Silicon-based compounds are promising supports for grafting of organometallic complexes, due to the possibility of surface modification by a variety of organic compounds [8,9].…”