[EN] PROCESS FOR THE PREPARATION OF ALPHA, BETA UNSATURATED ALDEHYDES BY OXIDATION OF ALCOHOLS IN THE PRESENCE OF A LIQUID PHASE [FR] PROCÉDÉ DE PRÉPARATION D'ALDÉHYDES ALPHA,BÊTA-INSATURÉS PAR OXYDATION D'ALCOOLS EN PRÉSENCE D'UNE PHASE LIQUIDE
potassium hydroxide, oleylamine, or oleic acid. Single-phase powders of a variety of intermetallic compounds were synthesized. Although not stable at the temperature of synthesis, high-temperature phases are accessible as well. The microwave-assisted polyol process opens up the possibility to synthesize intermetallic compounds in a fast and easily applicable one-step route, without the utilization of
微波辅助多元醇工艺用于合成 TM 系统中金属间相的纯相微晶或纳米晶样品(T = Co、Ni、Rh、Pd、Ir、Pt 和 M = Sn、Sb、Pb、Bi )。反应温度范围在 240 °C 和 300 °C 之间,几分钟到一小时的反应时间就足够了。为优化合成反应温度、反应时间和金属前驱体。为了获得相纯样品,该过程通过添加氢氧化钾、油胺或油酸进一步改进。合成了多种金属间化合物的单相粉末。虽然在合成温度下不稳定,但也可以进入高温相。
Bromide Ions Triggered Synthesis of Noble Metal–Based Intermetallic Nanocrystals
作者:An‐Liang Wang、Lijie Zhu、Qinbai Yun、Sumei Han、Li Zeng、Wenbin Cao、Xiangmin Meng、Jing Xia、Qipeng Lu
DOI:10.1002/smll.202003782
日期:2020.10
developed to synthesize a series of noble metal–based intermetallic nanocrystals, including hexagonal close‐packed (hcp) PtBi nanoplates, face‐centered cubic (fcc) Pd3Pb nanocubes, and hcp Pd2.5Bi1.5 nanoparticles. During the synthetic process, Br− ions play two important roles for the formation of ordered intermetallic structures: i) Br− ions can coordinate with the metal ions to decrease their reduction
具有良好定义的晶体结构和固定化学计量的有序金属间纳米材料有助于对其电子结构和催化性能的可预测控制。为了获得热力学稳定的金属间结构,由于退火引起的纳米材料的聚集和烧结,传统的高温退火方法仍然不能令人满意。在此,开发了一种通用的湿化学方法来合成一系列基于贵金属的金属间纳米晶体,包括六方密堆积(hcp)PtBi纳米板,面心立方(fcc)Pd 3 Pb纳米立方和hcp Pd 2.5 Bi 1.5纳米粒子。在合成过程中,溴-离子玩有序金属间结构的形成两个重要作用:1)溴-离子可与金属离子配位从而减少他们的还原电位减慢还原动力学。ⅱ)溴-离子可以与分子氧结合生成氧化蚀刻效果,因此重建原子排列,其是用于金属间结构的形成是有益的。作为概念验证应用,Pd 3 Pb纳米立方体被用作乙醇和甲醇氧化反应的电催化剂,与市售Pd黑色催化剂相比,其电化学性能得到了显着改善。
We first explore the co-modification between tensile-strained/electronic-modified Pd and electronic-modified intermetallic PtBi, to achieve superior performances towards formic acid electrocatalysis.
我们首先探讨了拉伸应变/电子改性钯与电子改性金属间铂铋之间的共改性,以实现甲酸电催化的卓越性能。
An Electrocatalyst for Methanol Oxidation in DMFC: PtBi/XC-72 with Pt Solid-Solution Structure
The electrocatalyst PtBi with a Ptsolid-solution phase has been synthesized using sodium hypophosphite as a reducing agent. The results of X-ray diffraction and X-ray absorption near-edge spectroscopy showed that in the presence of P, the Pt-Bi system forms an alloy with a Pt face-centered cubic solid-solution phase structure. Electrochemical test results revealed that PtBi/XC-72 exhibited a good