Microwave catalytic synthesis of ammonia from methane and nitrogen

2018 ◽  
Vol 8 (24) ◽  
pp. 6302-6305 ◽  
Author(s):  
Xinwei Bai ◽  
Sarojini Tiwari ◽  
Brandon Robinson ◽  
Casey Killmer ◽  
Lili Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Microwave Irradiation ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Value Added ◽  
Catalytic Synthesis ◽  
By Products

This study presents our recent findings that under microwave irradiation and/or microwave plasma conditions, nitrogen can react with methane to form ammonia and other value-added by-products, hydrogen and carbon nanotubes, at atmospheric pressure.

scholarly journals Synthesis of Multiwalled Carbon Nanotubes on Stainless Steel by Atmospheric Pressure Microwave Plasma Chemical Vapor Deposition

2020 ◽  
Vol 10 (13) ◽  
pp. 4468 ◽  
Author(s):  
Dashuai Li ◽  
Ling Tong ◽  
Bo Gao
Keyword(s):  
Carbon Nanotubes ◽  
Stainless Steel ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition

In this paper, we synthesize carbon nanotubes (CNTs) by using atmospheric pressure microwave plasma chemical vapor deposition (AMPCVD). In AMPCVD, a coaxial plasma generator provides 200 W 2.45 GHz microwave plasma at atmospheric pressure to decompose the precursor. A high-temperature tube furnace provides a suitable growth temperature for the deposition of CNTs. Optical fiber spectroscopy was used to measure the compositions of the argon–ethanol–hydrogen plasma. A comparative experiment of ethanol precursor decomposition, with and without plasma, was carried out to measure the role of the microwave plasma, showing that the 200 W microwave plasma can decompose 99% of ethanol precursor at any furnace temperature. CNTs were prepared on a stainless steel substrate by using the technology to decompose ethanol with the plasma power of 200 W at the temperatures of 500, 600, 700, and 800 °C; CNT growth increases with the increase in temperature. Prepared CNTs, analyzed by SEM and HRTEM, were shown to be multiwalled and tangled with each other. The measurement of XPS and Raman spectroscopy indicates that many oxygenated functional groups have attached to the surface of the CNTs.

One-step Synthesis of Carbon Nanotubes Network with Rich Oxygenated Functional Groups via Microwave Plasma in Atmospheric Pressure

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2679-2684
Author(s):  
Dashuai Li ◽  
Ling Tong ◽  
Bo Gao
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Ethanol Vapor ◽  
Transmission Electron ◽  
Synthesis Of Carbon Nanotubes ◽  
Oxygenated Functional Groups

AbstractAn atmospheric pressure microwave plasma tubular furnace apparatus (MPTF) for the rapid synthesis of carbon nanotubes (CNTs) has been developed. CNTs have been synthesized by an Argon-Hydrogen microwave plasma using ethanol vapor as carbon source with the furnace temperature of 800 °C at the atmospheric pressure. The synthesized CNTs have been analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and are shown to be multi-walled and tangled and chemically connected to form a high-density network with the diameter at the range of 25-70 nm. The measurement of X-ray photoelectron spectroscopy (XPS) indicates that a large number of oxygenated functional groups grown on the surface of CNTs. These properties proved that the CNTs could be utilized as nanoscale templates for various applications.

scholarly journals Direct Growth of Carbon Nanotubes on Aluminum Foil by Atmospheric Pressure Microwave Plasma Chemical Vapor Deposition

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Dashuai Li ◽  
Ling Tong
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Aluminum Foil ◽  
Plasma Chemical ◽  
Alumina Layer ◽  
Plasma Chemical Vapor Deposition

This paper is about the research that carbon nanotubes (CNTs) grow on aluminum foils without additional catalysts by atmospheric pressure microwave plasma chemical vapor deposition (AMPCVD) with the precursor of argon-hydrogen-ethanol. At different temperatures, a series of experiments that CNTs grow on aluminum foils were done with and without the alumina layer. The EDS results showed that iron impurities in aluminum foils catalyze the growth of CNTs. By measurements of SEM and HRTEM, tens of microns long and multi-walled CNTs are grown. The CNTs’ content in the sample changes more with the increase in temperature. The Raman measuring shows that CNTs have fewer defects with higher temperature. Finally, by measurements of EDS mapping and XRD on aluminum foil, the growth mechanism of CNTs was discussed.

Discussion of important factors in deposition of carbon nanotubes by atmospheric pressure microwave plasma torch

2007 ◽  
Vol 68 (5-6) ◽  
pp. 738-743 ◽  
Author(s):  
O. Jašek ◽  
M. Eliáš ◽  
L. Zajíčková ◽  
Z. Kučerová ◽  
J. Matějková ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atmospheric Pressure ◽  
Plasma Torch ◽  
Microwave Plasma ◽  
Microwave Plasma Torch

Carbon nanotubes synthesis in microwave plasma torch at atmospheric pressure

2006 ◽  
Vol 26 (5-7) ◽  
pp. 1189-1193 ◽  
Author(s):  
Ondřej Jašek ◽  
Marek Eliáš ◽  
Lenka Zajíčková ◽  
Vít Kudrle ◽  
Martin Bublan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atmospheric Pressure ◽  
Plasma Torch ◽  
Microwave Plasma ◽  
Microwave Plasma Torch

Obtaining Hydrogen and Carbon Materials from Hydrocarbonic Gas in Microwave Plasma Discharge at Amospheric Pressure

2015 ◽  
Vol 1084 ◽  
pp. 50-53
Author(s):  
Alekxey G. Zherlitsyn ◽  
Vladimir P. Shiyan ◽  
Nataliya N. Zyablova
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Material ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Plasma Source ◽  
Plasma Discharge ◽  
Active System ◽  
Waveguide Type ◽  
Gas Conversion ◽  
Plasmochemical Reaction

This paper presents the results of a pilot study of the process of hydrocarbonic gas conversion in microwave plasma discharge at atmospheric pressure. A microwave plasmatron of the waveguide type with the power of up to 3 kW was developed and used as a plasma source. Hydrocarbonic gas is both a chemical reagent and a plasma-forming environment in this plasmatron. A peculiarity of the developed microwave plasmatron is the presence of an active system for initiating and maintaining microwave discharge in its structure. It has been demonstrated that a high (up to 70%) degree of conversion of hydrocarbonic gases can be attained in microwave plasma discharge. The products of plasmochemical reaction are hydrogen and a carbon material. The carbon material contains up to 60% of carbon nanotubes. The phase structure of the material and the cross sizes of carbon nanotubes are provided herein.

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