SYNTHESIS OF ALLANTOIN USING HETEROPOLY COMPOUNDS AS CATALYSTS

Allantoin was synthesized with the yield as high as 68.5% using H3PW12O40. xH(2)O as catalyst. Optimum conditions for the synthesis were determined. It. was found that the heteropoly compound has higher catalytic activity than conventional inorganic acid catalysts (such as hydrochloric acid, etc.)

Catalytic Oxidation of Hexanol to Hexanal with H_2O_2 Over P-W Heteropoly Compounds

The syntheses of Keggin and Dawson-structural phospho-tungsto heteropoly compounds and their Peroxo-derivatives(PCWP), and the catalytic performance over this series of catalysts for the selective oxidation of hexanol to hexylaldehyde are reported. By means of IR, NMR and UV-DRS techniques the catalysts were characterized and a comparison of the structural properties of these catalysts before and after the reaction was made. The correlation between the catalytic performance and the structure of this series of catalysts was discussed as well.

CATIONIC RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN WITH KEGGIN-TYPE HETEROPOLYCOMPOUNDS AS SOLID ACID CATALYSTS

Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.

Synthesis of Tungstophosphates of Heteropoly Compound and Its Catalytic Property in Oxidative Desulfurization of Diesel

Several kinds of Tungstophosphates of Heteropoly Compounds （TPHC） with different compositions and the same structure were synthesized using the method of solid-phase reaction to change the tool ratio of Na4P2O7·10H2O, WO3 and Na2WO4 · 2H2O. TPHC, as a catalyst, was used in oxidative desulfurization of diesel. The results show that TPHC has catalytic activity. With THPC existing, the highest desulfurization rate reaches 51.85%, 32.6% higher than that yield without TPHC. And the desulfiarization rate increases with decreasing WO3. FT-IR spectra of TPHC shows that the catalytic activity is related to the activity of end oxygen（Od）.The more active Od is, the stronger the capability of obtaining or losing electron is. It means that TPHC has a good catalytic activity. FT-IR spectra of TPHC indicates that desulfurization rate is in linear correlation with Iw-Od/Ip-Od/ Iw-Od is intensity of W-Od vibration band, Ip-Od is intensity of P-Od vibration band） and correlation coefficient reaches 0.965.

Syntheses and Application of All-lithium Salts of Heteropolyacid as Electrolyte of Lithium-ion Battery

The all-lithium salts of heteropoly acid Li_xXM_ 12O_ 40(HPA-Li)(X=P, Si; M=Mo, W) were obtained via ion exchange and characterized by means of IR and UV spectroscopies, TG and elemental analyses. The conductivity of the electrolytic solution consisting of Li_3PW_ 12O_ 40 and PC/DME mixing solvent(1/2.5, volume ratio) is up to 7.2×10 -2 S/cm, being higher than that of LiClO_4 as the electrolyte. The all-lithium salts were used as electrolytes in secondary lithium-ion batteries. The discharge capacity of the PAS/Li batteries with Li_3PW_ 12O_ 40 electrolyte solutions reaches to 148 (mA·h)/g and the cyclic life is up to 380 times, much better than those of commercialized products with LiClO_4 and LiAsF_6 as electrolytes.

Synthesis，X－ray Structure and Spectral Propertiesofa Tetra－component Heteropoly Compound

he single crystal of a tetra-component heteropoly compound Mo_2Co_3O_(68) (H_2O_2)_2 ] [MoO_6]. 15(H_2O) was obtained in an aqueous solution with Na_2MoO_4 , Na_2WO_4, Co (NO_3)_2 and H_3PO_4 as starting materials. The erystallo-graphic data determined by means of X-ray diffraction analysis are: triclinic sys -tem,space group Pl ,Z= 2:a =1.9227(9) nm,b=1.9359(7)nm , c=1.2565(3)nm . a = 91. 43 (3), The Differential thermal and thermogravimetric analysis indicated the thermal stbility of the compound and its spectral properties were characterized by IR and XPS measurements .

Synthesis and Structure of K_3Na_3〔MnMo_9O_(32)〕·6H_2O

The title compound was synthesized from the manganese(Ⅶ ), titanium(Ⅲ ) and molybdate. It was crystallized as K3Na3[MnMo9O32,). 6H2O in the rhombohedral space group R32(155 # ), with a=b= 15. 521 (4), c= 12. 417 (6) A γ=120. 00 (1 )°. V= 2590. 1 (1 ) A 3, Z= 3, M.= 1778. 08, Dc= 3. 396g/cm3, λ(MoKa)=0. 71073A, μ= 42. 5 cm-1, F(000) ~ 2754 and the structure was determined by Xray diffraction methods, refined to a residual of 0. 048 for 1137 independent observablereflections with I≥3σ(I). There are Potassium, sodium canons, [MnMo9O32]6- anion, and crystalline water molecules in the complex. The anion may be constructedfrom a hypothetical MnIVMo6 Anderson species by removing three alternate MoO6, octehedra and placing three MoO6, octahedra above and below the MnMo3 unit, thus the resulting structure has D3 symmetry.

Hydrothermal Synthesis and Characterization of a Novel Organic Inorganic Hybrid Compound [Co(dien)_2](dienH_3)(H_3O)_7[P_2Mo_5O_(23)]_2·14H_2O

A new compound,[Co（dien）2]（dienH3）（H3O）7[P2Mo5O23]2·14H2O, has been hydrothermallly synthesized by using Na2MoO4,CoCl2, H3PO4 and dien, and structurally characterized by elemental analysis, X-ray powder diffraction analysis, SEM, IR and TG analysis. The results show that the compound is composed of a polyanion [P2Mo5O23]2^12, complex [Co（dien）2]^2＋ cation, protonated [dienH3]^3＋ , and forteen crystallization water molecule.

Electrochemical Studies on Some Tetracomponent Molybdovanadophosphate with Keggin Structure

ＥｌｅｃｔｒｏｃｈｅｍｉｃａｌＳｔｕｄｉｅｓｏｎＳｏｍｅＴｅｔｒａｃｏｍｐｏｎｅｎｔＭｏｌｙｂｄｏｖａｎａｄｏｐｈｏｓｐｈａｔｅｗｉｔｈＫｅｇｇｉｎＳｔｒｕｃｔｕｒｅＺＨＡＮＧＨｅｎｇ－ｂｉｎ，ＷＵＦａｎｇ，ＹＵＪｉａｎ－ｆｅｎｇ，ＷＵＴＯｎｇ－ｈａ...

Synthesis and Structure of K_6H_7〔Dy(SiMo_6W_5O_(39))_2〕·10H_2O

K6H7 [Dy(SiMo6W5O39)2] 10H2O, Mr= 4878. 5, is triclinic, sapcegroup P1 with a= 22. 697(5) A; b= 12. 835(4) A; c= 18. 216(6) A; a= 90. 56(2); β= 98. 24(2); γ= 90. 51 (2)°；V= 5251 (2) A3； Z= 2, Dc= 3.08 g/cm3; F(000) = 4321; S = 1. 550, μ= 183.65 cm-1. Refinement resulted in a final R of0.091, based on 7816 with I>3δ independent renections. The structure contains discrete [Dy (SiW5Mo6O39) 2] 13 - anions. The orientations fo the W and Mo atoms are random in the crystal. The MO6 octahedron and SiO4 tetrahedron are somewhat distorted.

Synthesis and Structure of K_6PMo_7V_2W_3O_(40)(H_2O)_(16)

The reddish--brown prismatic crystal of the title compoundK6PMo7V2W3O40., (H2O)16,, (Mr.= 2518. 8) crystallizes in tetragonal system, space groupP4n2(# 118), with a= 14. 083(1), b= 14. 083(2), c= 12. 572(3) A, V=2493. 6(l)A3 D.= 2. 72 g/cm'3 Z= 2.λ(MoKa) = 0. 71073 A, μ= 108. 9 cm-l, F(000) 1840, final R= 0. 038 and Rw= 0. 050 for 1388 observed reflections with I>3. 0σ(I).. The title compound contains heteropolyanion [(Mo7W3,V2)PO40]6- linked together byK+ ions and water molecules. The heteropolyanion has the well--known Keggin structure. The 12 metal atoms in the cage of the anion comprise seven Mo, three W and twoV atoms in a random distribution. The M--M (M= 7/12 Mo+ l/4W + l/6 V) average distance in the anion is 3. 535 A. The P--M distance is 3. 537A. The P--O distance is 1. 54 A, and the M--O distances are from 1. 64 to 2. 42A for O atoms coordinated to one, two and three M atoms respectively. Potassium ions are coordinated byeight O atoms from the anion and water molecules.

Structure of Potassium of Undecatungstomononickelosilicate

The compound K4[α-SiNiW11O38]·10H2O,Mr=3053.86,crystallizes in the orthorhombic, space group Pnn2 with cell dimensions a=14.203（8）,b=14.214（6）,c=12.460（3）,V=2515（2）,Z=2,Dc=4.03 g/cm￣3,λ（MoKα）=0.71069,μ=273.1 cm（-1）,F（000）=2672.The structure was solved by direct methods.The least-square refinement based on 1190 observed reflections[I】 6σ（I）] converged to a final R=0.076.The anion in the title compound is of α type Keggin structure,although the octahedron MO6 is greatly distorted. Atoms Ni and W are statistically distributed in the crystal.

Synthesis and Structure of K6PMo7V2W3O40（H2O）16

The reddish--brown prismatic crystal of the title compoundK6PMo7V2W3O40., (H2O)16,, (Mr.= 2518. 8) crystallizes in tetragonal system, space groupP4n2(# 118), with a= 14. 083(1), b= 14. 083(2), c= 12. 572(3) A, V=2493. 6(l)A3 D.= 2. 72 g/cm’3 Z= 2.λ(MoKa) = 0. 71073 A, μ= 108. 9 cm-l, F(000) 1840, final R= 0. 038 and Rw= 0. 050 for 1388 observed reflections with I】3. 0σ(I).. The title compound contains heteropolyanion [(Mo7W3,V2)PO40]6- linked together byK+ ions and water molecules. The heteropolyanion has the well--known Keggin structure. The 12 metal atoms in the cage of the anion comprise seven Mo, three W and twoV atoms in a random distribution. The M--M (M= 7/12 Mo+ l/4W + l/6 V) average distance in the anion is 3. 535 A. The P--M distance is 3. 537A. The P--O distance is 1. 54 A, and the M--O distances are from 1. 64 to 2. 42A for O atoms coordinated to one, two and three M atoms respectively. Potassium ions are coordinated byeight O atoms from the anion and water molecules.

Synthesis and Crystal Structure of[(CH_3)_4N]_4,H_2[ZnW_(11)SnO_(39)]·9H_2O

The complex [(CH_3)_4N]_4,H_2[ZnW_(11)SnO_(39)]·9H_2O Crystallizes in themonoclinic space group P21/m with cell dimensions: a=13. 164(3) A, b=21. 502(4)A, c=13. 234(3) A, a=90, β=91. 70(3), r=90, V=3744. 3(13) A3, Z=4,Mr= 3307. 15, Dc= 2. 933 g/cm3, A (MoKa ) = 0. 71073 A, u=175. 45 cm-1,F(000) = 2956, T= 293K, R=0. 0801 for 8401 observed reflections. The anion in thetitle compound is of a-typekeggin structure.

Transition metal-doped heteropoly catalysts for the selective oxidation of methacrolein to methacrylic acid

Heteropoly compounds with the general formula Cs1Mo.5X＋H3-o.5xP1.2MOllVO4o （M = Fe, Co, Ni, Cu or Zn） and CslCuyH3_2yP1.2MO11VO40 （y = 0.1, 0.3 or 0.7） were synthesized and then used as catalysts for the selective oxidation of methacrolein to methacrylic acid. The effects of the transition metals on the structure and activity of the catalysts were investigated. FTIR spectra showed that the transition metal-doped catalysts main- tained the Keggin structure of the undoped catalysts. X-ray diffraction results indicated that before calcination, the catalysts doped with Fe and Cu had cubic secondary structures, while the catalysts doped with Co, Ni or Zn had both triclinic and cubic phases and the Co-doped catalyst had the highest content of the triclinic form. Thermal treatment can decrease the content of the triclinic phase. NH3 temperature-programmed desorption and H2 tem- perature-programmed reduction results showed that the transition metals changed the acid and redox properties of the catalysts. The addition of Fe or Cu had positive effects on the activities of the catalyst which is due to the improvement of the electron transfer between the Fe or Cu and the Mo. The effects of the copper content on structure and catalytic activity were also investigated. The CSlCUo.3H2P1.2MO11VO40 catalyst had the best performance for the selective oxidation of methacrolein to methacrylic acid.

Selective Oxidation of Propane over CsFePVAsMo Heteropoly Compound Catalyst

Both the partially reduced and non-reduced multi-component heteropoly compound catalysts with Keggin structure were prepared and used for the selective oxidation of propane. The catalysts were characterized by IR, H2-TPR, NH3-TPD, SEM and XRD. The addition of Cs increased the selectivity of acrylic acid and acetic acid. The selective oxidation performance was greatly improved with the addition of As. Among all of the tested catalysts, the catalytic performance of the Cs1.8Fe0.16HxPVAs0.4Mo11O40 (non-reduced) was the best and the maximum yield of acrylic acid reached 16.42%.