Oxidative Dehydrogenation Properties of Novel Nanostructured Polyoxovanadate Based Materials

Abstract

A comparative study of the catalytic oxidative dehydrogenation of propane by a novel polyoxovanadate based open-framework material (Co-POV)-[Co 3 V 18 O 42 (H 2 O) 12 (XO 4 )]Á24H 2 O (X = V, S), which is composed of nanometer size vanadium oxide clusters interlinked by cobalt oxide {-O-Co-O-} motifs, showed that Co-POV has superior catalytic property as compared to its individual metal oxide constituents, vanadium oxide and cobalt oxide, and their mixture, with high propylene selectivity.

High Nuclearity Antimonato‐Polyoxovanadate Cluster {V15Sb6O42} as a Synthon for the Solvothermal in situ Generation of α‐ and β‐{V14Sb8O42} Isomers

“…The integration of semi‐metals, such as antimony, arsenic, germanium, or silicon, into polyoxovanadates (POVs) has attracted great interest because of the potential application of these materials in nanoscale magnetism (SMM=single molecular magnets), heterogeneous catalysis, or selective oxidation reactions . Antimonato polyoxovanadates (Sb‐POVs) belong to this class of compounds consisting of high‐nuclearity vanadate clusters, in which VO 5 square pyramids are partially substituted by Sb 2 O 5 handle‐like moieties.…”

“…The integration of semi-metals, such as antimony, arsenic, germanium, or silicon, into polyoxovanadates (POVs) has attracted great interest because of the potential applicationofthese materials in nanoscale magnetism (SMM = single molecular magnets), heterogeneous catalysis, or selectiveo xidation reactions. [1][2][3][4][5][6] Antimonato polyoxovanadates( Sb-POVs)belongt o this class of compounds consisting of high-nuclearity vanadate clusters,i nw hich VO 5 square pyramids are partially substituted by Sb 2 O 5 handle-like moieties. The structures can be derived from the archetype {V 18 O 42 }c luster [7] by replacingt wo, three, or four VO 5 polyhedra by Sb 2 O 5 units,t hus leadingt oas eries of compounds with general formula{ V 18Àn Sb 2n O 42 } 2nÀ (n = 2-4).…”

“…Recently,w eh ave studiedt he formationo fd ifferent Sb-POVs under hydrothermalc onditions with in situ X-ray diffraction experiments, [20] demonstrating that distinct clusters can be obtained by adjusting the amine concentration.T he results strongly suggestt hat the reduction of V V to V IV by the amine plays an importantr ole for Sb-POV formation thus explaining that for each synthesis of an ew Sb-POV the reaction conditions must be explored and adjusted by "trial-and-error".A way out of this unsatisfying situationw ould be the usage of ap re-formed Sb-POVclustera sastarting material, which can then be reacted with other educts for the generation of new compounds. Recently,w er eported the first water-soluble Sb-POV,n amely,{ Ni(en) 3 The highly unusual observation of the clustert ransformation encouraged us to explore this compound as as ynthon for the preparation of new Sb-POVs. The first experiment was performed with {Ni(en) 3…”

Lithium Argyrodites with Phosphorus and Arsenic: Order and Disorder of Lithium Atoms, Crystal Chemistry, and Phase Transitions

“…as well as their distinct host chemistry, where the guest exerts a templating effect on the electronic and the framework structure, leads to a beautiful and diverse chemistry 1–24. Polyoxovanadates were also investigated concerning catalytic properties,26 as materials for sorption applications27 and especially with respect to their magnetic properties because some may be viewed as prototypes as single molecule magnets (SMM) 28. In many high nuclearity polyoxovanadate clusters the V–V separations are at about 3 Å falling in the range between single bonding and non‐bonding separations.…”

Synthesis, Structure, and Solubility Studies of a New Arsenato‐Polyoxovanadate Cluster Compound: (NH4)4[V12As8O40(H2O)]·4H2O

“…POV's have also attracted high interest in the areas of supramolecular chemistry,13 as secondary electrode materials for advanced lithium batteries14,15 and as inorganic/organic hybrid materials for sorption applications 16. Polyoxovanadates were also investigated concerning catalytic properties17,18 and especially with respect to their magnetic properties because some may be viewed as prototypes for single molecule magnets (SMM) 19–23…”