PROCESS FOR TRANSFORMATION OF LIGNOCELLULOSIC BIOMASS OR CELLULOSE BY TUNGSTEN-OXIDE-BASED SOLID LEWIS ACID CATALYSTS AND A METAL THAT IS SELECTED FROM GROUPS 8 TO 11
丝状 0.1at% Zr 掺杂 (Nd0.33Eu0.38Gd0.28)Ba2Cu3Ox 超导体的高临界电流密度和超高压 TEM 研究
摘要:
摘要 我们通过溶液纺丝和在流动的0.1% O 2 + Ar 气体中部分熔化制备了丝状0.1 at% Zr 掺杂(Nd 0.33 Eu 0.38 Gd 0.28 )Ba 2 Cu 3 O x 超导体。通过沿垂直于灯丝长度的方向旋转样品,在高达 14 T 的外加磁场中,在 77 K 下测量传输临界电流密度 (J c )。通过施加超过 4 T 的场来检测 J c 的场依赖性的各向异性行为。在施加高达 11 T 的场时,Zr 掺杂样品的 J c 值高于未掺杂样品的 J c 值。通过施加高达 6 T 的场,在 77 K 时,在掺杂样品的优化角度测量的 J c 值超过 10 5 A/cm 2 。使用超高压 TEM 对样品进行透射电子显微镜 (TEM) 以明确钉扎中心。对于掺杂样品和未掺杂样品,均观察到 124 相的共生和取向 123 基体中的堆垛层错。Zr掺杂导致结构波动,无序范围短,为10-30 n
Microemulsion synthesis, structural characterization and dielectric properties of Ba 1-x Pb x ZrO 3 (0.05 ≤ x ≤ 0.20) nanoparticles
作者:Tokeer Ahmad、Mohd Ubaidullah、Irfan H. Lone、Dinesh Kumar、Omar A. Al-Hartomy
DOI:10.1016/j.materresbull.2017.01.044
日期:2017.5
The surface area of as-prepared nanoparticles was found to be in the range of 64–157 m 2 g −1 . The dielectric constant was found to increase (27.2–89.5) whereas the dielectric loss was found to decrease (0.07–0.002) on increasing the Pb 2+ ion concentration (0.05–0.20), suggesting effective dielectric characteristics of synthesized nanoparticles. Suitable pore morphology and high temperature stability
2-methylbutane was carried out at 0 °C over solid super acid catalysts which were prepared by treatment of various metal oxides with SbF5 under different conditions, and the preparation conditions that affect the catalyticbehavior of the catalyst were examined. Among the different base metal oxides, TiO2–ZrO2 became the most active catalyst when treated with SbF5. The maximum conversion to 2-methylbutane
Zirconium Schiff-base complex modified SBA-15 was synthesized and characterized by powder X-ray diffraction (XRD), BET nitrogen adsorption–desorption methods, IR spectroscopy and thermogravimetric analysis. The XRD and BET analyses show that textural properties of SBA-15 were retained during the grafting procedure. The modified SBA was successfully applied as a heterogeneous catalyst for the synthesis
合成了锆席夫碱配合物改性的 SBA-15,并通过粉末 X 射线衍射 (XRD)、BET 氮吸附-解吸方法、红外光谱和热重分析进行了表征。XRD 和 BET 分析表明 SBA-15 的结构特性在接枝过程中得以保留。改性的 SBA 作为多相催化剂成功应用于合成含氮吡嗪基杂环库,在水介质中以良好的收率。图文摘要锆席夫碱配合物改性介孔二氧化硅作为合成含氮杂环的有效催化剂吡嗪基杂环
Glucose dehydration to 5-hydroxymethylfurfural over phosphate catalysts
作者:V.V. Ordomsky、V.L. Sushkevich、J.C. Schouten、J. van der Schaaf、T.A. Nijhuis
DOI:10.1016/j.jcat.2012.12.028
日期:2013.4
activity of glucose transformation decreases in the order: NbPO > ZrPO > TiPO > AlPO, which was determined to correspond to the amount of strongacid sites on these catalysts. The selectivity to 5-hydroxymethylfurfural (HMF) varies in the range of 30–60% and depends on the ratio of Brönsted to Lewis acid sites. Excess of Lewis acidity on the catalyst leads to unselective glucose transformation into humins
Synthesis of isoprene from formaldehyde and isobutene over phosphate catalysts
作者:V.L. Sushkevich、V.V. Ordomsky、I.I. Ivanova
DOI:10.1016/j.apcata.2012.06.034
日期:2012.10
NbP, while the selectivity to isoprene showed the reverse tendency. The main side reaction was formaldehyde decomposition into carbon monoxide and dihydrogen. It is proposed that isoprene is formed on the Brønsted acid sites of the catalyst, while Mδ+Oδ− ion pairs are responsible for competitive carbon monoxide formation. The high resistance of ZrP and NbP catalysts to deactivation is accounted for
异丁烯与甲醛的汽相Prins缩合反应已在硼(BP),铝(AlP),钛(TiP),锆(ZrP)和铌(NbP)磷酸盐上进行了研究。通过元素分析,X射线衍射,氮气的低温吸附,氨的TPD和吡啶的FTIR对催化剂进行了表征。发现异丁烯和甲醛在磷酸盐上的转化按以下顺序增加:BP≪ AlP