Synthesis of Carbon Spheres/Tubes Using a Mixed-Valent Oxide-Catalytic Carbonization Process

1996 ◽  
Vol 454 ◽  
Author(s):  
Z. C. Kang ◽  
Z. L. Wang
Keyword(s):  
Natural Gas ◽  
Metal Oxides ◽  
Growth Mechanism ◽  
High Purity ◽  
Low Cost ◽  
Mixed Valence ◽  
Carbon Spheres ◽  
Spherical Form ◽  
Spiral Tube ◽  
Geometrical Shapes

ABSTRACTA mixed-valent oxide-catalytic carbonization (MVOCC) process is described for synthesizing monodispersed carbon spheres (or tubes) in macroscopic quantities at low cost. The technique uses natural gas and reusable catalysts and produces no environmental waste or pollution. The product is controlled to be either all of spheres (∼ 210 nm) or all of tubes with high purity (> 95 %). In spherical form, the product is solid and comprised of layered graphitic flakes containing paired pentagonal-heptagonal carbon-rings. In spiral tube form, the product is composed of twisted graphitic helix layers containing spherical nodes. A growth mechanism has been proposed, in which the pairing of pentagonal and heptagonal carbon-rings plays an important role. It is concluded that a change in fraction and nucleation rates of pentagonal, hexagonal and heptagonal carbon-rings results in the growth of different geometrical shapes. The success of using mixed-valence metal oxides as catalysts has opened a new field in catalysis research and applications.

A Low-Cost and High-Purity Porous Carbon Spheres Based on Starch Gel Toward High-Performance Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. 2050147
Author(s):  
Wen-Tong Yang ◽  
Hao-Yang Xie ◽  
Min-Peng Li ◽  
Rong-Rong Han ◽  
Chun Lu ◽  
...  
Keyword(s):  
Energy Density ◽  
High Purity ◽  
Porous Carbon ◽  
High Performance ◽  
Aqueous Electrolyte ◽  
Low Cost ◽  
Liquid Electrolyte ◽  
Carbon Spheres ◽  
Starch Gel ◽  
Porous Carbon Spheres

The development of low-cost, high-purity and high-performance porous carbon is of great significance for promoting the commercial application of supercapacitors. In this paper, porous carbon spheres (PCSs) with excellent electrochemical performance were obtained by carbonization and activation of starch gel spheres as precursor which is prepared by microemulsion process. The obtained PCSs exhibit both microporous and mesoporous structure, showing a large specific surface area of 1117.0 m2 g[Formula: see text] and exhibiting a high specific capacitance of 221.3 F g[Formula: see text]at a current density of 0.5 A g[Formula: see text] in aqueous electrolyte (and still displays capacity of 146.0 F g[Formula: see text] in ion liquid electrolyte). The PCSs//PCSs symmetric supercapacitor (SSC) based on aqueous electrolyte exhibits an energy density of 10.9 Wh kg[Formula: see text] at a power density of 300.0 W kg[Formula: see text], whereas that based on ion liquid electrolyte achieves a high energy density of 29.0 Wh kg[Formula: see text] at 650.0 W kg[Formula: see text]. The study provides a new idea to develop low-cost, high-purity and high-performance porous carbon materials for supercapacitors.

scholarly journals Iron, Nitrogen Co‐Doped Carbon Spheres as Low Cost, Scalable Electrocatalysts for the Oxygen Reduction Reaction

2021 ◽  
pp. 2102974
Author(s):  
Jingyu Feng ◽  
Rongsheng Cai ◽  
Emanuele Magliocca ◽  
Hui Luo ◽  
Luke Higgins ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Low Cost ◽  
Reduction Reaction ◽  
Carbon Spheres ◽  
Co Doped

Low-cost synthesis, fluorescent properties, growth mechanism and structure of CH3NH3PbI3 with millimeter grains

Optik ◽  
2017 ◽  
Vol 142 ◽  
pp. 293-300 ◽  
Author(s):  
Xinli Li ◽  
Lihua Li ◽  
Zhanhong Ma ◽  
Jinliang Huang ◽  
Fengzhang Ren
Keyword(s):  
Growth Mechanism ◽  
Low Cost ◽  
Fluorescent Properties

Design Analysis of a Micro Gas Turbine Combustion Chamber Burning Natural Gas

2012 ◽  
Author(s):  
André Perpignan V. de Campos ◽  
Fernando L. Sacomano Filho ◽  
Guenther C. Krieger Filho
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Low Cost ◽  
Mixture Fraction ◽  
Combustion Model ◽  
Inlet Temperature ◽  
Gas Combustion ◽  
Micro Turbine

Gas turbines are reliable energy conversion systems since they are able to operate with variable fuels and independently from seasonal natural changes. Within that reality, micro gas turbines have been increasing the importance of its usage on the onsite generation. Comparatively, less research has been done, leaving more room for improvements in this class of gas turbines. Focusing on the study of a flexible micro turbine set, this work is part of the development of a low cost electric generation micro turbine, which is capable of burning natural gas, LPG and ethanol. It is composed of an originally automotive turbocompressor, a combustion chamber specifically designed for this application, as well as a single stage axial power turbine. The combustion chamber is a reversed flow type and has a swirl stabilized combustor. This paper is dedicated to the diagnosis of the natural gas combustion in this chamber using computational fluid dynamics techniques compared to measured experimental data of temperature inside the combustion chamber. The study emphasizes the near inner wall temperature, turbine inlet temperature and dilution holes effectiveness. The calculation was conducted with the Reynolds Stress turbulence model coupled with the conventional β-PDF equilibrium along with mixture fraction transport combustion model. Thermal radiation was also considered. Reasonable agreement between experimental data and computational simulations was achieved, providing confidence on the phenomena observed on the simulations, which enabled the design improvement suggestions and analysis included in this work.

Constructing oxygen vacancy-enriched Fe2O3@NiO heterojunctions for highly efficient electrocatalytic alkaline water splitting

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yan Sang ◽  
Xi Cao ◽  
Gaofei Ding ◽  
Zixuan Guo ◽  
Yingying Xue ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
High Purity ◽  
Oxygen Evolution Reaction ◽  
High Efficiency ◽  
Low Cost ◽  
Dual Function ◽  
Alkaline Water ◽  
High Purity Hydrogen

Electrolysis of water to produce high-purity hydrogen is a very promising method. The development of green, high-efficiency, long-lasting and low-cost dual function electrocatalysts for oxygen evolution reaction (OER) and hydrogen...

Sign in / Sign up

Export Citation Format

Share Document