scholarly journals Recent Progress on Catalysts towards Electrocatalytic Nitrogen Reduction Reaction

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Xue YAO ◽  
Rui ZHAO ◽  
Zhengtong JI ◽  
Xingyou LANG ◽  
Yongfu ZHU ◽  
...  
Keyword(s):  
Triple Bond ◽  
High Performance ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Reduction Reaction ◽  
Operating Conditions ◽  
The Sustainable Development ◽  
Future Design ◽  
Promising Strategy ◽  
Production Of Ammonia

The energy-intensive Haber-Bosch process currently dominants the production of ammonia (NH3), an indispensable chemical for humans. For the sustainable development of society, highly efficient and green strategies to convert nitrogen (N2) to NH3 are urgently required. Electrocatalytic N2 reduction reaction (eNRR) is universally regarded as a promising strategy owing to the mild operating conditions and renewable energy supply. The key for eNRR is the high-performance catalysts, which activate the inert N-N triple bond and thus decrease the energy barrier. Herein, the recent theoretical and experimental progress on eNRR catalysts at room temperature and ambient pressure is summarized, aiming to provide a reference for future design of high-performance eNRR catalysts.

High-loaded sub-6 nm Pt1Co1 intermetallic compounds with high-efficient performance expression in PEMFCs

2021 ◽  
Author(s):  
Qingqing Cheng ◽  
Shuai Yang ◽  
Cehuang Fu ◽  
Liang-Liang Zou ◽  
Zhi-Qing Zou ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Intermetallic Compounds ◽  
High Performance ◽  
Reduction Reaction ◽  
Operating Conditions ◽  
Practical Application ◽  
Efficient Performance ◽  
High Efficient ◽  
High Metal

High-loaded oxygen reduction reaction (ORR) Pt intermetallic compounds with high performance expression under PEMFC operating conditions are prerequisite for practical application. Nevertheless, high metal-loading would lead to the severe agglomeration...

High Performance PdxCuy Bimetal Catalysts With Adjustable Faraday Current Efficiency for Nitrogen Fixation

2021 ◽  
Author(s):  
Hongxi Zhang ◽  
Zengyao Wang ◽  
Jianfeng Shen ◽  
Mingxin Ye
Keyword(s):  
Nitrogen Fixation ◽  
Current Efficiency ◽  
Atmospheric Pressure ◽  
High Performance ◽  
Room Temperature ◽  
Product Yield ◽  
Reduction Reaction ◽  
Low Density ◽  
Nitrogen Reduction

The electro-catalytic nitrogen reduction reaction (NRR) at room temperature and atmospheric pressure had a great potential in NH3 production, but the low product yield because of the low density of...

PREPARATION OF ULTRAFINE W–Cu COMPOSITE POWDER USING ULTRASONIC-ASSISTED ELECTROLESS PLATING

2013 ◽  
Vol 27 (19) ◽  
pp. 1341004 ◽  
Author(s):  
LIMEI HUANG ◽  
LAIMA LUO ◽  
XIAOYU DING ◽  
XIANG ZAN ◽  
YU HONG ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Electroless Plating ◽  
High Performance ◽  
Room Temperature ◽  
Composite Powder ◽  
Surface Defects ◽  
Cell Structure ◽  
Reduction Reaction ◽  
Composite Powders ◽  
Ultrasonic Assisted

W – Cu ultrafine/nanocomposite powders have high sintering activity, so ultrafine/nanotechnology of W – Cu composite powders is one of the main methods to obtain fully dense, high-performance W – Cu composite materials. Cu -coated ultrafine W composite powders were synthesized by ultrasonic-assisted electroless plating process with non-noble metal activation pretreatment at room temperature in this paper. The growth mechanism of Cu layers and surface morphologies and composition of initial ultrafine W powders, pretreated W powders and Cu -coated W powders were analyzed by field emission scanning electron microscopy (FE-SEM), and energy dispersion spectrometry (EDS). The results show that the uniformly Cu coated W composite powder is successfully synthesized without conventional sensitization and activation steps by ultrasonic-assisted electroless plating at room temperature. The Cu layers on the ultrafine W powders had cell structure with dense, uniform distribution. The growth mechanism of Cu layers appears as follows: the surfaces of pretreated W powders appear linear-like and lamellar-like surface defects which act as activated sites. The reactants in the plating solution were adsorbed on catalytic activity surfaces of powders and happened oxidation–reduction reaction. The growth and aggregation mechanisms of Cu particles after nucleation are stripy Cu -cells grew up, bend, bifurcated, and aggregated, then wounding into a cellular structure, like "wrapping wool clusters" in the life. Finally, Cu cells grow up and merge into a layer.

High Performance Optoelectronic Devices Based on Bright Perovskite Nanocrystals Synthesized at Room Temperature

2018 ◽  
Author(s):  
Sotirios Christodoulou ◽  
Francesco Di Stasio ◽  
Santanu Pradhan ◽  
Inigo Ramiro ◽  
Yu Bi ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Optoelectronic Devices ◽  
Perovskite Nanocrystals

Ultra-High Temperature Ceramics (UHTCs) via Reactive Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1159-1163 ◽  
Author(s):  
Guo Jun Zhang ◽  
Wen Wen Wu ◽  
Yan Mei Kan ◽  
Pei Ling Wang
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Performance ◽  
Thermal Protection ◽  
Ambient Pressure ◽  
Stable Phase ◽  
Reactive Sintering ◽  
Dissociation Temperature ◽  
Monolithic Ceramics

Current high temperature ceramics, such as ZrO2, Si3N4 and SiC, cannot be used at temperatures over 1600°C due to their low melting temperature or dissociation temperature. For ultrahigh temperature applications over 1800°C, materials with high melting points, high phase composition stability, high thermal conductivity, good thermal shock and oxidation resistance are needed. The transition metal diborides, mainly include ZrB2 and HfB2, have melting temperatures of above 3000°C, and can basically meet the above demands. However, the oxidation resistance of diboride monolithic ceramics at ultra-high temperatures need to be improved for the applications in thermal protection systems for future aerospace vehicles and jet engines. On the other hand, processing science for making high performance UHTCs is another hot topic in the UHTC field. Densification of UHTCs at mild temperatures through reactive sintering is an attracting way due to the chemically stable phase composition and microstructure as well as clean grain boundaries in the obtained materials. Moreover, the stability studies of the materials in phase composition and microstructures at ultra high application temperatures is also critical for materials manufactured at relatively low temperature. Furthermore, the oxidation resistance in simulated reentry environments instead of in static or flowing air of ambient pressure should be evaluated. Here we will report the concept, advantages and some recent progress on the reactive sintering of diboride–based composites at mild temperatures.

Star-shaped arylacetylene resins derived from silicon

2020 ◽  
Vol 40 (8) ◽  
pp. 676-684
Author(s):  
Niping Dai ◽  
Junkun Tang ◽  
Manping Ma ◽  
Xiaotian Liu ◽  
Chuan Li ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Mechanical Test ◽  
Flexural Modulus ◽  
Mechanical Analysis ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Structures And Properties ◽  
High Performance Resin

AbstractStar-shaped arylacetylene resins, tris(3-ethynyl-phenylethynyl)methylsilane, tris(3-ethynyl-phenylethynyl) phenylsilane, and tris (3-ethynyl-phenylethynyl) silane (TEPHS), were synthesized through Grignard reaction between 1,3-diethynylbenzene and three types of trichlorinated silanes. The chemical structures and properties of the resins were characterized by means of nuclear magnetic resonance, fourier-transform infrared spectroscopy, Haake torque rheomoter, differential scanning calorimetry, dynamic mechanical analysis, mechanical test, and thermogravimetric analysis. The results show that the melt viscosity at 120 °C is lower than 150 mPa⋅s, and the processing windows are as wide as 60 °C for the resins. The resins cure at the temperature as low as 150 °C. The good processabilities make the resins to be suitable for resin transfer molding. The cured resins exhibit high flexural modulus and excellent heat-resistance. The flexural modulus of the cured TEPHS at room temperature arrives at as high as 10.9 GPa. Its temperature of 5% weight loss (Td5) is up to 697 °C in nitrogen. The resins show the potential for application in fiber-reinforced composites as high-performance resin in the field of aviation and aerospace.

scholarly journals Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch-Leaf” Electrode for High-Energy Sodium–Sulfur Batteries

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wenyan Du ◽  
Kangqi Shen ◽  
Yuruo Qi ◽  
Wei Gao ◽  
Mengli Tao ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Electrochemical Reaction ◽  
Molecular Layer ◽  
Specific Capacity ◽  
High Energy ◽  
Reduction Reaction ◽  
Biomimetic Design ◽  
Co Nanoparticles ◽  
Sodium Sulfur

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.

scholarly journals Lateral PbS Photovoltaic Devices for High Performance Infrared and Terahertz Photodetectors

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1692
Author(s):  
Emmanuel K. Ampadu ◽  
Jungdong Kim ◽  
Eunsoon Oh
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Photovoltaic Device ◽  
Photovoltaic Devices ◽  
Temperature Spectrum ◽  
Terahertz Region ◽  
Room Temperature Spectrum ◽  
Ftir Spectrometer ◽  
Titanium Substrates ◽  
Deposition Conditions

We fabricated a lateral photovoltaic device for use as infrared to terahertz (THz) detectors by chemically depositing PbS films on titanium substrates. We discussed the material properties of PbS films grown on glass with varying deposition conditions. PbS was deposited on Ti substrates and by taking advantage of the Ti/PbS Schottky junction, we discussed the photocurrent transients as well as the room temperature spectrum response measured by Fourier transform infrared (FTIR) spectrometer. Our photovoltaic PbS device operates at room temperature for wavelength ranges up to 50 µm, which is in the terahertz region, making the device highly applicable in many fields.

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