V^IIIV^IV₃O₃(PO₄)₃:  A Novel Vanadium Phosphate for Selective Oxidation of Light Hydrocarbons

Abstract

A novel vanadium(IV) phosphate V III V IV 3 O 3 (PO 4 ) 3 has been synthesized and crystallized (1073 K, sealed silica tube, a few milligrams of PtCl 2 as mineralizer). According to the single-crystal structure analysis [orthorhombic, F2dd (No. 63), Z ) 24, a ) 7.2596(8) Å, b ) 21.786(2) Å, c ) 38.904(4) Å (lattice parameters from Guinier photographs), R 1 ) 0.032, wR 2 ) 0.067, κ-CCD diffractometer, 83 949 reflections measured, 6836 independent, 5986 with I > 2σ(I), 299 variables], V III V IV 3 O 3 (PO 4 ) 3 belongs to the Lipscombite/Lazulite structure family. At 1073 K V III V IV 3 O 3 (PO 4 ) 3 is in thermodynamic equilibrium with (VO) 2 P 2 O 7 , VO 2 , and VPO 4 . Substitution of V 3+ in V III V IV 3 O 3 (PO 4 ) 3 by Cr 3+ and Fe 3+ is possible. Like vanadylpyrophosphate the oxide phosphates M III V IV 3 O 3 (PO 4 ) 3 (M III : V, Cr, Fe) show significant catalytic activity in selective oxidation of n-butane and 1-butene to maleic acid anhydride.

Reversible Li Insertion Studies on V4O3(PO4)3as High Energy Storage Material for Li-Ion Battery Applications

“…. [31][32][33][34][35] The orthorhombic phase V 4 O 3 (PO 4 ) 3 consists of infinite chains of face sharing VO 6 octahedra and PO 4 tetrahedra. The three dimensional structure is formed by perpendicular chains along a, b axis connected with common vertices of oxide ion and PO 4 tetrahedra (Figure 1b) …”

“…For the synthesis route of V 4 O 3 (PO 4 ) 3 , we use the same route that was described by E. Benser and co-workers 32 in which stoichiometric amounts of homemade precursors VO 2 , VPO 4 , and (VO) 2 P 2 O 7 are placed in a carbon coated evacuated quart tube at 800…”

Novell Ternary and Polynary Vanadium(IV) Phosphates as Catalysts for Selective Oxidations of Light Hydrocarbons

“…This rather high number of vanadium phosphates is due to the ability of vanadium to form various oxidation states as well as to the stability of phosphates with a wide range of ratios n(vanadium oxide) : n(phosphorus oxide). As a result of these investigations, the novell vanadium (III, IV) oxidephosphate V III V IV 3 O 3 (PO 4 ) 3 was found coexisting with (VO) 2 P 2 O 7 [13,14] at 1073 K [2]. It also has been found, that the oxygen equilibrium pressures over vanadium phosphates at 1073 K may vary over a range of more than 20 orders (10 -3 ≤ p(O 2 ) ≤ 10 -24 atm [4]).…”

“…It also has been found, that the oxygen equilibrium pressures over vanadium phosphates at 1073 K may vary over a range of more than 20 orders (10 -3 ≤ p(O 2 ) ≤ 10 -24 atm [4]). The oxygen equilibrium pressure for the decomposition of (VO) 2 [16 -19]. Synthesis, crystal structures, and of catalytic properties of these compounds are described in this report.…”

Catalytic Properties of Silver Vanadium Phosphates in n‐Butane Oxidation – Considerations on the Impact of the [VxOy] Substructure

“…Some attempts to find alternatives for (VO) 2 P 2 O 7 catalyst have been reported in the past by Agaskar et al [7], Davis et al [8], and Glaum et al [9,10]. A rational approach for the design of alternative materials used in [7,9,10] was based on the structural incorporation of vanadium atoms in combination with other elements like Nb, Sb [7], or Cr, Fe, Co, Ni, Cu [9,10] within a phosphate framework in order to achieve improved site isolation [11,12] on the catalyst surface by modification of the bulk crystal structure. Unfortunately, the performance of the single-phase M-V-P-O catalysts was by far inferior compared to the (VO) 2 P 2 O 7 catalyst.…”