10058-44-3Relevant articles and documents
Synthesis and characterization of new iron phosphatooxalates: [(S)-C5H14N2] [Fe4(C2O4)3(HPO4) 2(H2O)2] and [(S)-C5H14N2] [Fe4(C2O4)3(HPO4) 2]
Chang, Wen-Jung,Lin, Hsiu-Mei,Lii, Kwang-Hwa
, p. 233 - 239 (2001)
Two new organically templated iron(II) phosphatooxalates, [(S)-C5H14N2] [Fe4(C2O4)3(HPO4) 2(H2O)2] (1) and [(S)-C5H14N2] [Fe4(C2O4)3(HPO4) 2] (2), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction and Moessbauer spectroscopy. Crystal data are as follows: compound 1, triclinic, P1 (No. 1), a = 7.6999(4) A, b = 7.9542(4) A, c = 9.8262(5) A, α = 74.8444(7)°, β = 81.7716(8)°, γ = 85.4075(8)°, V = 574.34(8) A3, Z = 1, and R1 = 0.0255; compound 2, monoclinic, P21 (No. 4), a = 7.5943(8) A, b = 7.8172(8) A, c = 18.318(2) A, β = 99.111(2)°, V = 1073.8(3) A3, Z = 2, and R1 = 0.0281. The structure of 1 consists of dimers of edge-sharing FeO6 octahedra that are linked by phosphate and oxalate groups to generate a three-dimensional framework with intersecting tunnels parallel to the [100] and [010] directions. Diprotonated (S)-2-methylpiperazinium cations are located at the intersections of these tunnels. Compound 1 crystallizes as a minor product when a racemic mixture of 2-methylpiperazine is used in the synthesis, and can be prepared as a major product with a small amount of 2 if optically pure (S)-2-methylpiperzine is used. The structure of 2 is similar to that of 1 except that the coordination around the iron centers in the dimer are square pyramidal and octahedral. The two compounds are the first 3-dimensional phosphatooxalates containing a chiral amine.
Hydrated iron phosphates FePO4·nH2O and Fe4(P2O7)3·n H2O as 3 V positive electrodes in rechargeable lithium batteries
Masquelier, Christian,Reale, Priscilla,Wurm, Calin,Morcrette, Mathieu,Dupont, Loic,Larcher, Dominique
, p. A1037-A1044 (2002)
Hydrated Fe111 phosphates were investigated as positive electrode materials in lithium batteries. Reversible lithium insertion into amorphous and crystalline FePO4·nH2O and Fe4(P2O7)3
A Raman study of iron-phosphate crystalline compounds and glasses
Zhang, Liying,Brow, Richard K.
, p. 3123 - 3130 (2011)
Ferrous and ferric phosphate crystalline compounds and glasses were studied using Raman spectroscopy. A comparison of the spectra from crystalline and glassy ortho-, pyro-, and metaphosphates indicates that similar phosphate anions constitute the structures of the respective materials, and some information about the compositional dependence of the phosphate-site distributions in the glasses can be gleaned from relative peak intensities. A correlation exists between the average P-O bond distance and the Raman peak frequencies in the crystalline compounds, and this correlation is used to provide information about the structures of the iron phosphate glasses. For example, the average P-O bond distance is estimated to decrease from about 1.57 A for iron metaphosphate glasses (O/P～3.0) to 1.54 A for iron orthophosphate glasses (O/P～4.0). These bond distances are in good agreement with those reported from diffraction studies of similar glasses.
Effect of structure on the Fe3+/Fe2+ redox couple in iron phosphates
Padhi,Nanjundaswamy,Masquelier,Okada,Goodenough
, p. 1609 - 1613 (1997)
To understand the role of structure on the position of the octahedral Fe3+/Fe2+ redox couple in compounds having the same polyanions, four iron phosphates: Li3Fe2(PO4)3, LiFeP2O
A new layered organically templated iron(II) phosphite, (C 2H10N2)[Fe3(HPO3) 4]. Hydrothermal synthesis, crystal structure and spectroscopic and magnetic properties
Chung, U-Chan,Mesa, Jose L.,Pizarro, Jose L.,Lezama, Luis,Garitaonandia, Jose S.,Chapman, Jon P.,Arriortua, Maria I.
, p. 2705 - 2713 (2004)
The (C2H10N2)[Fe3(HPO 3)4] compound has been synthesized by using mild hydrothermal conditions under autogeneous pressure and the ethylenediamine molecule as templating agent. The compound crystallizes in the triclinic P1 space group with unit-cell parameters a=5.416(1), b=5.416(1), c=13.977(2)A, α=80.64(2), β=85.25(1), γ=60.03(1)°and Z=1. The final R-factors were R1=0.053 [wR2=0.092]. The crystal structure is constructed of layers stacked along the c-axis. The sheets contain FeO6 octahedra linked by (HPO3)2- phosphite oxoanions to give rise to Fe3O12 trimeric units sharing faces. The IR spectrum shows the characteristic bands of the phosphite and ethylenediammonium ions. From the diffuse reflectance spectrum, the Dq parameter of 805cm-1 has been calculated for the iron(II) cation in slightly distorted octahedral geometry. The Moessbauer spectrum exhibits two doublets characteristic of two crystallographically independent iron(II) ions in octahedral symmetry. Magnetic measurements indicate the existence of antiferromagnetic interactions.
On the crystal structure and thermal decomposition of ammonium-iron(III) bis(hydrogenphosphate)
Alfonso, Belen F.,Blanco, Jesus A.,Fernandez-Diaz, M. Teresa,Trobajo, Camino,Khainakov, Sergei A.,Garcia, Jose R.
, p. 1791 - 1796 (2010)
NH4Fe(HPO4)2 and its deuterated form have been synthesized as monophasic polycrystalline materials. Their crystal structures, including hydrogen positions, were determined by Rietveld refinement and Fourier synthesis using
Synthesis of two-dimensional transition-metal phosphates with highly ordered mesoporous structures for lithium-ion battery applications
Yang, Dan,Lu, Ziyang,Rui, Xianhong,Huang, Xiao,Li, Hai,Zhang, Wenyu,Lam, Yeng Ming,Hng, Huey Hoon,Zhang, Hua,Yan, Qingyu,Zhu, Jixin
, p. 9352 - 9355,4 (2014)
Materials with ordered mesoporous structures have shown great potential in a wide range of applications. In particular, the combination of mesoporosity, low dimensionality, and well-defined morphology in nanostructures may exhibit even more attractive features. However, the synthesis of such structures is still challenging in polar solvents. Herein, we report the preparation of ultrathin two-dimensional (2D) nanoflakes of transition-metal phosphates, including FePO4, Mn3(PO4)2, and Co3(PO4)2, with highly ordered mesoporous structures in a nonpolar solvent. The as-obtained nanoflakes with thicknesses of about 3.7nm are constructed from a single layer of parallel-packed pore channels. These uniquely ordered mesoporous 2D nanostructures may originate from the 2D assembly of cylindrical micelles formed by the amphiphilic precursors in the nonpolar solvent. The 2D mesoporous FePO4 nanoflakes were used as the cathode for a lithium-ion battery, which exhibits excellent stability and high rate capabilities. Ultrathin two-dimensional (2D) nanoflakes of transition-metal phosphates, including FePO4 (see TEM image), Mn 3(PO4)2, and Co3(PO 4)2, with highly ordered mesoporous structures have been successfully synthesized in a nonpolar solvent. The use of the 2D mesoporous FePO4 nanoflake as a cathode in a lithium-ion battery resulted in excellent stability and high rate capabilities.
Phase Equilibria in the Fe2O3-P2O 5 System
Zhang, Liying,Schlesinger, Mark E.,Brow, Richard K.
, p. 1605 - 1610 (2011)
Four ferric phosphate compounds were identified in the Fe2O 3-P2O5 system and the liquidus surfaces in the subsystems Fe3PO7-FePO4, FePO 4-Fe4(P2O7)3, and Fe 4(P2O7)3-Fe(PO3) 3 were determined. The results are significantly different from those presented by Wentrup in 1935. Fe3PO7 is the stable ferric oxophosphate compound, not Fe4P2O11, and Fe3PO7 decomposes in air at 1090°C. The congruent melting point of FePO4 (1208°C) is similar to what was reported, but Fe4(P2O7)3 melts congruently at 945°C, about 300°C lower than claimed by Wentrup. Fe(PO 3)3, for which the melting temperature has not been previously reported, melts congruently at 1205°C. Eutectic points exist at 58.0 mol% Fe2O3 (1070°C), 42.7% Fe2O 3 (925°C), and 37.0% Fe2O3 (907°C). The latter two eutectic points bracket the conventional glass-forming range for iron phosphate melts under consideration as alternative hosts for nuclear wastes.
Crystal structure refinement and magnetic properties of Fe4(P2O7)3 studied by neutron diffraction and moessbauer techniques
Elbouaanani,Malaman,Gerardin,Ijjaali
, p. 412 - 420 (2002)
Fe4(P2O7)3 was prepared from Fe(PO3)3 and FePO4 at 940°C under oxygen. The unit cell is monoclinic, space group P21/n, with a = 7.389(2) A, b = 21.337(1) A, c = 9.517(2) A, β = 90(1)°, and Z = 4. The crystallographic structure has been determined from a single crystal through direct methods and difference Fourier synthesis and refined to R = 0.10 (Rw = 0.09). The three-dimensional framework is built up from Fe2O9 clusters of two face-sharing octahedra, linked by bent diphosphates P2O7 (P-O-P ～ 156°). Fe4(P2O7)3 is antiferromagnetic below TN = 50 K. The magnetic structure has been determinated by means of powder neutron diffraction. There are four antiferromagnetic iron sublattices corresponding to the four crystallographically distinct iron atoms. The magnetic moments are antiferromagnetically coupled inside the Fe2O9 dimers, in agreement with the Goodenough rules. They are parallel to the c axis and have 4.55(5) μB value at 1.7 K. The magnetic interactions are discussed. Moessbauer spectra are fitted with four doublets and sextuplets in the paramagnetic and antiferromagnetic states, respectively. Their rather high isomer shifts are explained by the inductive effect.
Iron phosphate nanoparticle catalyst for direct oxidation of methane into formaldehyde: Effect of surface redox and acid-base properties
Hara, Michikazu,Kamata, Keigo,Matsuda, Aoi,Tateno, Haruka
, p. 6987 - 6998 (2021/11/13)
The effect of various iron phosphate and oxide catalysts on the direct oxidation of methane (CH4) to formaldehyde (HCHO) with molecular oxygen (O2) as the sole oxidant was studied using a fixed-bed flow reactor. Five crystalline iron-containing catalysts (FePO4, Fe3O3(PO4), Fe4(P2O7)3, Fe2P2O7, and α-Fe2O3) with different iron coordination geometries, iron oxidation states, and Fe/P ratios were synthesized by the sol-gel method using malic acid or aspartic acid. The Fe/P molar ratio had a significant effect on the oxidation catalysis; CH4 conversion increased with the Fe/P molar ratio, although the selectivity to HCHO decreased. Trigonal FePO4 nanoparticles synthesized by the malic acid-aided method with an Fe/P molar ratio of 1/1 exhibited the highest activity for the selective formation of HCHO among the catalysts tested, including FePO4 synthesized by a conventional method. Despite the much higher oxidizing ability of Fe2O3 than FePO4, the oxidation of CH4 using Fe2O3 resulted in the formation of only CO2. In contrast, the temperature-programmed reaction of FePO4 with CH4 gave Fe2P2O7 with the formation of HCHO as a primary product, and Fe2P2O7 reacted with O2 to regenerate FePO4. Based on mechanistic studies including the catalyst effect, kinetics, pulse-reaction experiments, and IR spectroscopy, the bulk structural change between FePO4 and Fe2P2O7 is not involved during the catalysis and the surface redox and acid-base properties of FePO4 are considered to play an important role in CH4 oxidation with the structure preservation of bulk FePO4. The combination of redox-active Lewis acidic iron sites and weakly-basic phosphate units likely contributes to the C-H activation of CH4 and the suppression of complete oxidation to CO2, respectively.
