研究了结晶 Pd 1-x Ag x -H y (x = 0-0.35) 合金作为代表储氢材料化学无序系统的模型系统。在 2.4-400 K 的宽温度范围内进行了广泛的 1 H 弛豫率(R 1 、R 1p 和 R 2 )测量。通过 NMR 光谱研究了银浓度高达 35 at.% 的钯-银合金第一次。确定并表征了磁偶极弛豫(氢扩散)、Korringa 弛豫、顺磁性杂质离子的弛豫和与四极金属核的交叉弛豫的弛豫机制。在 Pd-H 和 Pd 1-x Ag x -H 系统中首次假设并证明了 1 H 和四极 105 Pd 核自旋之间存在交叉弛豫。在所研究的钯银合金中发现存在不止一种扩散氢的跳跃过程。由于没有发现与频率无关的 R 1 与 T 区域,因此只能获得 Korringa 常数的下限估计值。这些值明显高于其他人报告的值。
Room‐Temperature Hydrogenation of Citral Catalyzed by Palladium–Silver Nanocrystals Supported on SnO
<sub>2</sub>
作者:Shuo Wang、Rongan Shen、Zheng Chen、Jiaxi Wang、Dingsheng Wang、Yadong Li
DOI:10.1002/ejic.201500057
日期:2015.4
performance for the hydrogenation of the conjugated double bond compared with the corresponding Pd–Ag catalysts. The selectivity of citronellal increased from 0 (for Pd0.7Ag0.3/C) to 76 % (for Pd0.7Ag0.3–SnO2/C was used) after the addition of SnO2. On the basis of these results, we developed a catalyst (Pd0.6Ag0.4–SnO2/C) with the best catalytic performance for the selective hydrogenation of citral (the conversion
Pd–Ag alloy nanocages have been developed for light-driven catalytic hydrogenation, in which Pd provides active sites for hydrogenation reactions and Ag offers plasmonic properties to convert light into heat.
Low temperature hydrogen and deuterium isotherms for Pd and some of its binary alloys
作者:Ted B. Flanagan、Da Wang
DOI:10.1016/j.jallcom.2020.157434
日期:2021.3
demonstrates that hydrogen (deuterium) isotherms for Pd and its alloys can be measured down to quite low temperatures opening up new possibilities for the characterization of these systems. Deuterium isotherms are determined in this research down to 233 K and to 218 K for the Pd 0.95 Rh 0.05 and Pd 0.90 Rh 0.10 alloys, respectively. At low temperatures and moderate pressures, Pd and its alloys absorb significantly
摘要 这项研究表明,Pd 及其合金的氢(氘)等温线可以测量到非常低的温度,这为表征这些系统开辟了新的可能性。在本研究中,Pd 0.95 Rh 0.05 和 Pd 0.90 Rh 0.10 合金的氘等温线分别确定为 233 K 和 218 K。在低温和中等压力下,Pd 及其合金吸收的 H 或 D 比在 298 K 时明显更多。例如,在 218 K 和 ≈ 1 bar 时,Pd 0.90 Rh 0.10 合金吸收 D 高达 (D/Pd 0.90 Rh 0.10 ) ≈ 0.8,摩尔比,而该比率在 298 K 时 ≈ 0.70 (Sakamoto et al., 1994) [1]。在低温下达到平衡的速度相对较快,例如,在 218 K 时,Pd 与 D 2 的平衡建立在 ≈ 10 m 内。
A PdAg bimetallic nanocatalyst for selective reductive amination of nitroarenes
Herein we have identified an optimal catalyst, Pd1Ag1.7, for the tandem reductive amination between nitroarenes and aldehydes (selectivity > 93%). Key to the success is the ability to control the compositions of the investigational Pd1−xAgx (x = 0–1) catalysts, as well as the clear composition dependent activity/selectivity trend observed in this study. This catalyst features a wide substrate scope, excellent recyclability, activity and selectivity under ambient conditions.
Nanoalloying effects on the catalytic activity of the formate oxidation reaction over AgPd and AgCuPd aerogels
作者:Qiao Wang、Fuyi Chen、Longfei Guo、Tao Jin、Huazhen Liu、Xiaolu Wang、Xiaofang Gong、Yaxing Liu
DOI:10.1039/c9ta00664h
日期:——
D-Ag25Cu25Pd50 nanoalloy exhibits significantly enhanced FOR activity with a mass activity of 2.73 A mg−1 and a specific activity of 10.10 mA cm−2 and a higher current density in the chronoamperometry test than that of commercial Pd/C and most previously reported Pd-based catalysts. A downshift of the d-band centre is observed in D-Ag25Cu25Pd50 aerogels compared to the pure Pd catalyst. This work highlights
直接甲酸酯燃料电池(DFFC)由于其高功率密度,易于燃料存储/运输和良好的环境兼容性而成为有前途的能量转换设备,但是即使铂族金属(PGM,例如Pt和Pd)电催化剂也受到其限制。在碱性介质中甲酸催化反应的低催化活性和稳定性。本文研究了Ag和Cu元素在AgPd和AgCuPd纳米合金中的促进作用以及AgCuPd纳米合金对FOR催化的脱合金处理。各种Ag x Pd 100- x,Ag y Cu 50- y Pd 50和脱合金Ag y Cu 50- y Pd合成了50种气凝胶(以下称为D-Ag y Cu 50- y Pd 50),并将其电化学性能与最新的Pd / C催化剂进行了比较。D-Ag 25 Cu 25 Pd 50纳米合金表现出显着增强的FOR活性,其质量活性为2.73 A mg -1,比活性为10.10 mA cm -2,并且在计时电流法测试中的电流密度高于商用Pd / C和大多数以前报道的Pd基催化剂。在D-Ag