Catalysts Conversion Of Hydroxypropionic Acid Or Its Derivatives To Acrylic Acid Or Its Derivatives
申请人:THE PROCTER & GAMBLE COMPANY
公开号:US20130274512A1
公开(公告)日:2013-10-17
Methods for catalytically dehydrating hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof to acrylic acid, acrylic acid derivatives, or mixtures thereof with high yield and selectivity and without significant conversion to undesired side products, such as, acetaldehyde, propionic acid, and acetic acid, are provided. The catalysts are mixed condensed phosphates.
Micrometer LiMn0.7Fe0.3PO4âC particles consisting of nanopores are prepared using MnPO4·H2O as the precursor. The nanopores were formed by the thermal decomposition of the precursor. Fe doping and carbon coating were realized in one step during the heat treatment. Polyethylene glycol (PEG) was used as the carbon source and milled with the other precursor to form the carbon coating throughout the whole micrometer particle sample. Due to the short ion transportation distance of the active materials caused by the nanopores, the composite displays high discharge capacity, and good rate capability and cycle stability. With only 4% carbon, the capacity of LiMn0.7Fe0.3PO4âC reaches 132 mA h gâ1 under the galvanostatic chargeâdischarge mode, and 140 mA h gâ1 under the constant currentâconstant voltage (CCâCV) charge mode.
以 MnPO4Â-H2O 为前驱体,制备了由纳米孔组成的微米级 LiMn0.7Fe0.3PO4âC 颗粒。纳米孔是通过前驱体的热分解形成的。铁掺杂和碳涂层在热处理过程中一步完成。使用聚乙二醇(PEG)作为碳源,并与其他前驱体一起研磨,在整个微米颗粒样品中形成碳涂层。由于纳米孔隙使活性材料的离子传输距离缩短,复合材料显示出较高的放电容量、良好的速率能力和循环稳定性。碳含量仅为 4% 的 LiMn0.7Fe0.3PO4âC 在电静态充放电模式下的容量达到 132 mA h gâ1 ,在恒流恒压(CCâCV)充电模式下的容量达到 140 mA h gâ1 。
Synergetic Fe substitution and carbon connection in LiMn1−xFexPO4/C cathode materials for enhanced electrochemical performances
作者:Su-Yuan Yan、Cheng-Yang Wang、Rong-Min Gu、Shuai Sun、Ming-Wei Li
DOI:10.1016/j.jallcom.2014.12.182
日期:2015.4
crystal structures caused by Fe substitution and the 3D carbon coating/connection originating from ACM carbonization. LiMn 1−xFex PO 4 materials exhibit two discharge plateaus at ∼4.0 and ∼3.5 V (vs. Li + /Li), whose heights respectively reflect the redox potentials of Mn 3+ /Mn 2+ and Fe 3+ /Fe 2+ couples. The plateaus’ lengths correspond to the Mn/Fe ratio in LiMn 1−xFex PO 4 and are affected by
摘要 为了提高锂离子电池正极材料 LiMnPO 4 的倍率和循环性能,将 Mn 部分置换为 Fe,合成了 LiMn 1− x Fe x PO 4 ( x = 0.2, 0.3, 0.4, 0.5) 固溶体并进行了调查。两亲碳质材料 (ACM) 形成良好的碳涂层并通过三维 (3D) 碳网络连接 LiMn 1- x Fe x PO 4 微晶。协同的Fe取代和碳连接显着提高了样品的倍率容量和循环稳定性。优化的 LiMn 0.6 Fe 0.4 PO 4 /C 样品的放电容量为 0.05 C 时 160 mA hg -1、1 C 时 148 mA hg -1 和 20 C 时 115 mA hg -1。所有样品均具有良好的容量保持率( >92%) 在 1 C 下进行 50 次充电/放电循环后。电化学性能的增强主要归因于 LiMn 1− x Fe x PO 4 /C 样品中锂离子和电子传输的改善,分别主要是由于
Hydrothermally Controlled Growth of MnPO<sub>4</sub>·H<sub>2</sub>O Single-Crystal Rods
Rod-like MnPO4·H2O single crystallites were hydrothermally prepared by the reaction of Mn(NO3)2 with H3PO4 at 130 °C for 16 h. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), infrared spectrum (IR), and their magnetic properties were evaluated on a vibrating sample magnetometer (VSM). The synthesized single-crystal rods have diameters of 0.1–0.66 μm and lengths of up to several micrometers. The influences of different phosphates, the volume ratio between reaction materials, reaction temperature, and reaction time on the morphology and phase of the final products under hydrothermal conditions are discussed. A possible formation mechanism has been proposed on the growth of MnPO4·H2O single-crystal rods.
Infrared spectra of the monohydrates of manganese(III) phosphate and manganese(III) arsenate: relation to the compounds of the kieserite family
作者:Slobotka Aleksovska、Vladimir M. Petruševski、Bojan Šoptrajanov
DOI:10.1016/s0022-2860(96)09720-7
日期:1997.6
Abstract The IR spectra of the title compounds suggest that the hydrogen bonding is stronger in MnAsO 4 ·H 2 O than in MnPO 4 ·H 2 O. The similarity of the IR spectra of these two compounds with the spectra of magnesium sulfate monohydrate (kieserite) and the members of its family (compounds with the general formula MIIRO 4 ·H 2 O, where MII is Mg, Mn, Fe, Co, Ni or Zn, and R is S or Se) suggests a
摘要 标题化合物的 IR 光谱表明,MnAsO 4 ·H 2 O 中的氢键比 MnPO 4 ·H 2 O 中的氢键强。这两种化合物的 IR 光谱与一水硫酸镁(kieserite ) 及其家族成员(通式为 MIIRO 4 ·H 2 O 的化合物,其中 MII 是 Mg、Mn、Fe、Co、Ni 或 Zn,R 是 S 或 Se)表明它们之间的结构相似,与公布的衍射数据一致。光谱和衍射研究表明,由于高电荷和较小的 Mn 3+ 阳离子的协同作用以及 PO 4 AsO 4 氧的质子受体能力增加,MnPO 4 ·H 2 O 中的氢键更强和MnAsO 4 ·H 2 O 比在硅镁铝石类化合物中。