以磷酸铁盐为催化剂:乳酸氧化脱氢制丙酮酸

用磷酸铁盐作催化剂气相催化氧化乳酸 ,乳酸选择性地转化为丙酮酸 ,收率可达到50 % 。

Mixed salts for lithium iron phosphate-based batteries operated at wide temperature range

To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB were investigated as alternative lithium salts to LiPF6 in non-aqueous electrolytes.LiFePO4/Li half cells using LiPF6,LiBF4-LiBOB and LiTFSI-LiBOB slats as lithium salts were investigated by galvanostatic cycling,cyclic voltammetry,thermogravimetric analysis.The results show that LiBF4-LiBOB and LiTFSI-LiBOB mixed salts are much more thermally stable than LiPF6.Corrosion of Al foil in the LiTFSI-based electrolytes can be suppressed successfully by the addition of LiBOB as a co-salt.The electrochemical performance of LiBF4-LiBOB and LiTFSI-LiBOB mixed salts based cells are both better than that of LiPF6-based cell.LiTFSI-LiBOB mixed salt based electrolyte is considered to be a very promising electrolyte candidate for Li-ion batteries that will be used in wide-temperature applications.

Comparative Study on Characteristics of P Fixation by Mn, Fe and Al

An experiment was conducted to examine the role of Mn in P fixation through comparing with Al and Fe. Hydroxides and oxides of Al, Fe and Mn were prepared in lab under opened and closed conditions to react with phosphate. The newly formed Mn hydroxide showed the strongest P-fixing abilityl even several times higher than Fe hydroxide, but became the lowest rapidly due to ageing when exposed to air. Mn oxide showed the lowest p-fixing ability. Therefore, a sound consideration on P fixation should be based on both quantities and p-fixing abilities of the compounds of Fe, Al and Mn. The importance of Mn on P availability should receive more attention especially under oxidation-reduction dynamic conditions.

Types of Crystalline Iron Oxides and Phosphate Ad－sorption in Variable Charge Soils

The types, contents and morphologies of crystalline Fe oxides and their relations to phosphate adsorptionon the clay fractions in soils with variable charge in southern China were investigated by means of XRD, TEM,EMA and chemical analysis methods.Results indicated that the types and contents of crystalline Fe oxidesvaried with the soils examined. The dominant crystalline Fe oxide was hematite in the latosols and goethitesin the red soils.In yellow-brown soils, the only crystalline Fe oxide was goethite.The difference between Aldand Alo came mainly from the Al substituting for Fe in the pe oxides. The crystal morphology of goethiteappeared mainly as subrounded flat or iso-dimensional rather than acicular particles. Hematites occurredin plates of various thickness. Their MCDa/MCDc ratios in the latosols and red soils were generally above1.5 and below 1.5, respectively. The MCD values of goethites and hematites were 15-25nm and 20-35nm,and their specific surface areas were 80-120m￣2/g and 35-75m￣2/g, respectively.The goethite crystals weregenerally smaller. Variations of the total amounts of crystalline Fe oxi es in clay fractions were not related tophosphate adsorption. The types, contents and morphologies of crystalline Fe oxides in the soils remarkablyaffected phosphate adsorption characteristics of the soils. The phosphate adsorption of goethite was muchgreater than that of hematite. The higher the MCD /MCDc rotio of hematite, the lower the phosphateadsorption.

Effects of phosphate precursors on morphology and oxygen evolution reaction activity of NiFe(oxy)hydroxide on nickel foams

NiFe(oxy)hydroxides nanosheets were synthesized on nickel foams via co-precipitation and electrochemical activation. It is found that the phosphate precursors(Na_(3)PO_(4), Na_(2)HPO_(4)and NaH_(2)PO_(4)) have diverse effects on the morphology and thus the oxygen evolution reaction activity of the formed final catalysts. The resulting NiFe(oxy)hydroxides nanosheets prepared with Na_(2)HPO_(4)demonstrate a low overpotential of 205 m V to achieve a current density of 50 mA/cm^(2) with a Tafel slope down to 30 mV/dec in 1 mol/L KOH, and remain stable for 20 h during stability test.

Iron Phosphate Coating: A Novel Approach to Controlling Pyrite Oxidation

A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.

Bio-decomposition of rock phosphate containing pyrites by Acidithiobacillus ferrooxidans

Leaching soluble phosphorus from rock phosphate containing pyrites by Acidithiobacillus ferrooxidans (A.f.) is feasible, and the reaction mechanism is as follows. Pyrites are oxidized by A.f. to produce H_2SO_4 and FeSO_4; the rock phosphate is decomposed by H_2SO_4, forming soluble phosphorus compounds; and Fe2+ from FeSO_4 is oxidized to Fe^3+, providing energy for the growth of A. f.. In this process, as H_2SO_4 is produced in the reaction, an acidic condition in the culture medium is formed, which benefits the growth of A. f. and aids both continuous oxidation of pyrites and leaching of soluble phosphorus from rock phosphate. The fraction of phosphorous leached can reach the largest in the presence of 1.0 g/L Fe^3+, 200 mg/L Mg^2+ and 400 mg/L NH_4^+. The optimal technological parameters on the fraction of phosphorous leached are as follows: the volume fraction of inocula of A. f., the mass ratio of pyrites to rock phosphate and the pH value are in ranges of 5%-25%, 3:1-5:1 and 1.8-2.2, respectively.

Electrochemical performances of LiFePO_4/C composites prepared by molten salt method

LiFePO4/C composites were synthesized by a molten salt (MS) method using the mixture of LiCl,LiOH and NaCl.The prepared LiFePO4/C composites are characterized by X-ray diffractometry (XRD),field emission scanning electron microscopy (FESEM) and charge-discharge test.XRD patterns indicate that LiFePO4 prepared in the temperature range of 550-700 ℃ crystallizes well in an olivine-type structure.Through FESEM images,the sphere-like and homogeneous particles of 0.2 μm can be observed.The charge-discharge test shows that the materials prepared at 600 ℃ for 12 h have good electrochemical performance.At the rates of 0.2C (34 mA/g) and 0.5C,the discharge capacities are 144.6 and 122.3 mA·h/g,respectively,together with good cycle performances.

Effects of Zn/P ratio on structures and properties of zinc-iron phosphate glasses

Effects of Zn/P ratio on the structures and properties of glasses with the general composition of （80-x）ZnO-20Fe2O3-xP2O5 （x=40, 45, 50, 55, 60） （molar fraction, %） were investigated. Glass structure was measured by infrared absorption spectrum. Glass density （/9） was measured by the Archimedes method. Coefficients of thermal expansion （a） and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate （DR）in water at 90 ℃ for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. （80-x）ZnO-20Fe2O3-xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with a〈8.0× 10^-6℃^-1.

Inflnence of PH on Chemical Forms of Phosphate Ad－sorbed on Goethite Snrfaces

Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinategroups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentatecorrdination to that of bidentate one with increasing pH of the solution. By influencing types of phosphateions in solutions, pH affected the chemical forms of P on goethite surfaces. The amount of OH￣- displacedby phosphate on goethite surfaces was the most at pH 7.0, the second at pH 9.0, and the least at pH 4.5.

Recursive calibration for a lithium iron phosphate battery for electric vehicles using extended Kalman filtering

In this paper,an efficient model structure composed of a second-order resistance-capacitance network and a simply analytical open circuit voltage versus state of charge(SOC) map is applied to characterize the voltage behavior of a lithium iron phosphate battery for electric vehicles(EVs).As a result,the overpotentials of the battery can be depicted using a second-order circuit network and the model parameterization can be realized under any battery loading profile,without a special characterization experiment.In order to ensure good robustness,extended Kalman filtering is adopted to recursively implement the calibration process.The linearization involved in the calibration algorithm is realized through recurrent derivatives in a recursive form.Validation results show that the recursively calibrated battery model can accurately delineate the battery voltage behavior under two different transient power operating conditions.A comparison with a first-order model indicates that the recursively calibrated second-order model has a comparable accuracy in a major part of the battery SOC range and a better performance when the SOC is relatively low.

Preparation and ζ-potential characterization of highly dispersible phosphate—functionalized magnetite nanoparticles

By the combination of high-temperature organometallic synthesis and phase transfer through complete ligand-exchange withmixed phosphate, highly water-dispersible Fe3O4nanoparticles with narrow size distribution are obtained, which show appli-cable response to magnetic field. IR and -potential characterization of this system provides insights into ligand structures onparticle surface.