scholarly journals Synthesis of Bimetallic PdAg Nanoparticles and Their Electrocatalytic Activity toward Ethanol

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Fahui Gao ◽  
Yanru Yin ◽  
Zhengshuai Cao ◽  
Hongliang Li ◽  
Peizhi Guo
Keyword(s):  
Electrocatalytic Activity ◽  
Bimetallic Nanoparticles ◽  
Molar Ratio ◽  
Face Centered Cubic ◽  
Ethanol Electrooxidation ◽  
Uniform Size ◽  
Catalytic Current ◽  
The Face ◽  
Alloy Nanostructures ◽  
Face Centered

Palladium-based bimetallic nanoparticles (NPs) have been studied as important electrocatalysts for energy conversion due to their high electrocatalytic performance and the less usage of the noble metal. Herein, well-dispersed PdAg NPs with uniform size were prepared via oil bath accompanied with the hydrothermal method. The variation of the Ag content in PdAg NPs changed the lattice constant of the face-centered cubic alloy nanostructures continuously. The Pd/Ag molar ratio in the PdAg alloy NPs affected their size and catalytic activity toward ethanol electrooxidation. Experimental data showed that PdAg NPs with less Ag content exhibited better electrocatalytic activity and durability than pure Pd NPs owing to both the small size and the synergistic effect. PdAg-acac-4 with the Pd/Ag molar ratio of 4 : 1 in the start system possessed the highest catalytic current density of 2246 mA/mg for the electrooxidation of ethanol. The differences in the morphology and electrocatalytic activity of the as-made PdAg NPs have been discussed and analyzed.

Investigation on Structure Transition of Fullerene During Mechanical Alloying and Subsequent Treatments

2000 ◽  
Vol 15 (7) ◽  
pp. 1528-1537
Author(s):  
Z. G. Liu ◽  
H. Ohi ◽  
K. Masuyama ◽  
K. Tsuchiya ◽  
M. Umemoto
Keyword(s):  
Mechanical Milling ◽  
Polymerization Process ◽  
Molar Ratio ◽  
Face Centered Cubic ◽  
Scanning Calorimetry ◽  
Structure Transition ◽  
Characterization Methods ◽  
Fullerene Soot ◽  
The Face ◽  
Face Centered

Mechanical milling of fullerene (soot containing C60/C70 fullerenes in a 8:2 molar ratio) was investigated through various characterization methods. It was found that mechanical milling would not destroy the molecular structure of fullerene C60 (C70), while the long-range order of the face-centered-cubic crystalline structure was easily modified and transformed into amorphous phase, a mixture of fullerene C60 (C70) polymers and monomers. Differential scanning calorimetry analysis revealed a recovery of polymers to pristine fullerene molecules at 678 K, which is much higher than the reported depolymerization temperature of fullerene polymers induced by photo irradiation and by high-pressure–temperature processes. It is suggested that the contaminated Fe acts as a catalyst in the polymerization process.

Microstructures and Magnetic Properties of CoPt-C Nanogranular Films

2017 ◽  
Vol 727 ◽  
pp. 985-990
Author(s):  
Lei Ma ◽  
Mu Fen He ◽  
Gang Cheng ◽  
Zheng Fei Gu
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Amorphous State ◽  
Nanocomposite Films ◽  
Face Centered Cubic ◽  
Doping Amount ◽  
Uniform Size ◽  
The Face ◽  
Face Centered ◽  
High Density Magnetic Recording

CoPt-C films were fabricated on silicon substrate by dc reactive magnetron sputtering followed by vacuum annealing. The effects of C additions and annealing temperature on the microstructure and magnetic properties were investigated. The as-deposited films had flat, compact surfaces and face-centered cubic structure, which transforms into the face-centered tetragonal structure after thermal annealing at 700°C for 1 hour. The grain size of CoPt increased with the annealing temperature but decreased with increasing C content. No carbide appearing, the C content exists in amorphous state in the nanocomposite films, and it is homogeneous distributed between the CoPt nanograins, which have the benefit to restrain grain growth and obtain isolated CoPt particles with uniform size. The fct-CoPt films annealed at 700°C exhibited high in-plane coercivity, up to 4200 Oe at room temperature and better square degrees. In the CoPt-C granular films, the best doping amount is about 35 at.% C. These CoPt-C films with novel embedded structure and moderate coercivity have shown promise for high density magnetic recording medium.

Atomic Organization In Magnetic Bimetallic Nanoparticles: An Experimental And Theoretical Approach

2003 ◽  
Vol 789 ◽  
Author(s):  
Marie-Claire Fromen ◽  
Samuel Dennler ◽  
Marie-José Casanove ◽  
Pierre Lecante ◽  
Joseph Morillo ◽  
...  
Keyword(s):  
Surface Segregation ◽  
Bimetallic Nanoparticles ◽  
Interaction Model ◽  
Face Centered Cubic ◽  
Chemical Route ◽  
Energy Filtering ◽  
Pure Cobalt ◽  
Transmission Electron ◽  
The Face ◽  
Face Centered

ABSTRACTUltrafine bimetallic CoRh nanoparticles synthesized by a soft chemical route with compositions ranging from pure cobalt to pure rhodium are investigated using high-resolution and energy filtering transmission electron microscopy techniques as well as wide angle x-ray scattering. In parallel, they are simulated with the use of an n-body semi-empirical interaction model: quenched molecular dynamics and Monte-Carlo Metropolis simulated annealing are performed on these nanoparticles in order to find their most stable isomers as a function of composition and size. A progressive evolution from an original polytetrahedral structure to the face-centered cubic structure with increasing Rh content is observed in these particles. Strong tendency to Co surface segregation is both experimentally evidenced and confirmed by the simulations.

A study of interface sliding at F.C.C.-B.C.C. boundaries in a Cu-Zn alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 422-423
Author(s):  
F. Monchoux ◽  
A. Rocher ◽  
J.L. Martin
Keyword(s):  
Face Centered Cubic ◽  
Creep Tests ◽  
High Voltage Electron Microscopy ◽  
Diffusion Treatment ◽  
Voltage Electron ◽  
The Face ◽  
Face Centered ◽  
Interface Sliding ◽  
Zn Alloy ◽  
Made In

Interphase sliding is an important phenomenon of high temperature plasticity. In order to study the microstructural changes associated with it, as well as its influence on the strain rate dependence on stress and temperature, plane boundaries were obtained by welding together two polycrystals of Cu-Zn alloys having the face centered cubic and body centered cubic structures respectively following the procedure described in (1). These specimens were then deformed in shear along the interface on a creep machine (2) at the same temperature as that of the diffusion treatment so as to avoid any precipitation. The present paper reports observations by conventional and high voltage electron microscopy of the microstructure of both phases, in the vicinity of the phase boundary, after different creep tests corresponding to various deformation conditions.Foils were cut by spark machining out of the bulk samples, 0.2 mm thick. They were then electropolished down to 0.1 mm, after which a hole with thin edges was made in an area including the boundary

scholarly journals Size-Dependent Alloying Ability of Immiscible W-Cu Bimetallic Nanoparticles: A Theoretical and Experimental Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1047
Author(s):  
Hongbo Zhang ◽  
Tao Liu ◽  
Siqi Zhao ◽  
Zhanyuan Xu ◽  
Yaozha Lv ◽  
...  
Keyword(s):  
Binary Systems ◽  
Bimetallic Nanoparticles ◽  
Driving Forces ◽  
Phase Particle ◽  
Phase Segregation ◽  
High Yield ◽  
Universal Method ◽  
Face Centered Cubic ◽  
Original Size ◽  
Face Centered

The preparation of alloyed bimetallic nanoparticles (BNPs) between immiscible elements is always a huge challenge due to the lack of thermodynamic driving forces. W–Cu is a typical immiscible binary system, and it is difficult to alloy them under conventional circumstances. Here, we used the bond energy model (BEM) to calculate the effect of size on the alloying ability of W–Cu systems. The prediction results show that reducing the synthesis size (the original size of W and Cu) to less than 10 nm can obtain alloyed W–Cu BNPs. Moreover, we prepared alloyed W50Cu50 BNPs with a face-centered-cubic (FCC) crystalline structure via the nano in situ composite method. Energy-dispersive X-ray spectroscopy (EDS) coupled with scan transmission electron microscopy (STEM) confirmed that W and Cu are well mixed in a single-phase particle, instead of a phase segregation into a core-shell or other heterostructures. The present results suggest that the nanoscale size effect can overcome the immiscibility in immiscible binary systems. In the meantime, this work provided a high-yield and universal method for preparing alloyed BNPs between immiscible elements.

MINIMAL KNOTTING NUMBERS

2009 ◽  
Vol 18 (08) ◽  
pp. 1159-1173 ◽  
Author(s):  
CASEY MANN ◽  
JENNIFER MCLOUD-MANN ◽  
RAMONA RANALLI ◽  
NATHAN SMITH ◽  
BENJAMIN MCCARTY
Keyword(s):  
The Body ◽  
Computer Algorithm ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Lattice ◽  
The Face ◽  
Face Centered ◽  
Body Centered Cubic Lattice

This article concerns the minimal knotting number for several types of lattices, including the face-centered cubic lattice (fcc), two variations of the body-centered cubic lattice (bcc-14 and bcc-8), and simple-hexagonal lattices (sh). We find, through the use of a computer algorithm, that the minimal knotting number in sh is 20, in fcc is 15, in bcc-14 is 13, and bcc-8 is 18.

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