scholarly journals Using nitrogen-doped carbon nanotubes as a catalyst support for selective hydrogenation of cinnamaldehyde

2017 ◽  
Vol 20 (K1) ◽  
pp. 20-27
Author(s):  
Truong Huu Tri ◽  
Nguyen Dinh Lam
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Selective Hydrogenation ◽  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Chemical Vapor ◽  
Active Phase ◽  
Chemical Vapor Deposition Method ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon nanotubes (N-CNTs) has been applied in different areas for over two last decade thanks to their novel properties. In this work, N-CNTs were produced by using chemical vapor deposition method, this material was used as catalyst support for nanoparticles paladi (Pd) catalyst. The support and catalyst Pd/N-CNTs were characterized by several techniques including Raman spectrum, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption - desorption isotherms (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The catalyst was tested for the selective hydrogenation of cinnamaldehyde (CAL), The result of this study shows that the catalyst Pd/N-CNTs exhibits a high selectivity towards the C=C bond, over 91% of hydrocinnamaldehyde (HCAL) obtained at about 70% of CAL conversion. The obtained results also show that the present nitrogen atoms in the carbon architecture and functional groups of oxygen in the N-CNTs material have altered the surface properties, as enhancing the dispersion and anchoring active phase on the surface of the support.

Nitrogen-Doped Carbon Nanotubes and Graphene Nanohybrid for Oxygen Reduction Reaction in Acidic, Alkaline and Neutral Solutions

2015 ◽  
Vol 30 ◽  
pp. 50-58 ◽  
Author(s):  
Ji Yue Liu ◽  
Zan Wang ◽  
Jing Yan Chen ◽  
Xin Wang
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Chemical Vapor ◽  
Electrochemical Measurement ◽  
Reduction Reaction ◽  
Neutral Medium ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon nanotubes (N-CNTs) have beenprepared on FeNi catalyst by plasma-enhanced chemical vapor deposition in amixture of N2, O2, and CH4. On the opened topof CNT, multi-layer graphene grown self-assembly was observed by transmissionelectron microscopy and high resolution transmission electron microscopy. Thenanohybrid film analyzed by scanning electron microscopy exhibited a porous and3D morphology and pyridinic and graphitic nitrogen structure confirmed by x-rayphotoelectron spectroscopy. Electrochemical measurement indicated that the filmfacilitated about three-electron transferpathway for oxygen reduction reaction in neutral medium and two-electronreductions in both alkaline and acidic solutions.

scholarly journals Synthesis, Characterization and Properties of Nitrogen Doped Carbon Nanotubes

2021 ◽  
Author(s):  
Quping Zhu
Keyword(s):  
Carbon Nanotubes ◽  
Water Absorption ◽  
Chemical Vapor ◽  
Analytical Techniques ◽  
Molar Ratio ◽  
Chemical Vapor Deposition Method ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon ◽  
Organic Amines ◽  
Silicon Based

Abstract In this work, nitrogen doped carbon nanotubes (N-CNTs) were prepared by a facile chemical vapor deposition method using Fe/SBA-15 molecular sieve as the catalyst and different organic amines as carbon source and nitrogen source. The morphology, structure and composition of the obtained samples were characterized by a series of analytical techniques. The results revealed that the as-obtained N-CNTs are hollow bamboo like nanofibers with a diameter of 30-50 nm and a smooth surface. The effect of the organic amines on the yield, composition, morphology and properties of the N-CNTs were investigated. The N-CNTs prepared with diethylamine (DEA) have the highest yield (2.2 g · (g · cat) - 1). The water absorption of the as-synthesized N-CNTs samples increases with the increase of nitrogen content. The N-CNTs prepared with ethylenediamine (EDA) have the highest N/C molar ratio(0.35) and the highest water absorption (224.4 mg · g-1). The thermal conductivity (TC) of the silicon-based composites increases with the increase of N-CNTs. However, the N/C molar ratio of N-CNTs has a negative effect on the TC of silicon-based composites.

In Situ Filling of Fe/Ni Oxide Nanowire into Carbon Nanotubes Doped with Nitrogen in CH4/H2/Air Plasma

2011 ◽  
Vol 15 ◽  
pp. 51-56 ◽  
Author(s):  
Xin Wang ◽  
Ya Yu Wang ◽  
Wei Tao Zheng ◽  
Zan Wang
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor ◽  
Air Plasma ◽  
Catalyst Film ◽  
Metal Oxide Nanoparticle ◽  
Transmission Electron ◽  
Nitrogen Doped Carbon ◽  
Ni Oxide

Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized using air as the nitrogen carrier gas and CH4 as the carbon source by plasma-enhanced chemical vapor deposition over a thin catalyst film of Fe50Ni50. Transmission electron microscopy and high resolution transmission electron microscopy measurements have indicated that the N-CNTs grew with a tip-type growth mode. When H2 was added to the CH4/air plasmas during the N-CNTs growth stage, it was found that Fe/Ni oxide nanowire was filled into the nanotube. However, without adding H2 in the CH4/air mixture plasma, only metal oxide nanoparticle was found on the tip of the N-CNT.

scholarly journals Synthesis of high-purity carbon nanotubes over alumina and silica supported bimetallic catalysts

2009 ◽  
Vol 15 (4) ◽  
pp. 263-270 ◽  
Author(s):  
Sanja Ratkovic ◽  
Erne Kiss ◽  
Goran Boskovic
Keyword(s):  
Carbon Nanotubes ◽  
Bimetallic Catalysts ◽  
Supported Catalysts ◽  
Chemical Vapor ◽  
Active Phase ◽  
Precipitation Method ◽  
High Yield ◽  
Chemical Vapor Deposition Method ◽  
Hydrogen Flow ◽  
Graphite Nanoparticles

Carbon nanotubes (CNTs) were synthesized by a catalytic chemical vapor deposition method (CCVD) of ethylene over alumina and silica supported bimetallic catalysts based on Fe, Co and Ni. The catalysts were prepared by a precipitation method, calcined at 600 ?C and in situ reduced in hydrogen flow at 700?C. The CNTs growth was carried out by a flow the mixture of C2H4 and nitrogen over the catalyst powder in a horizontal oven. The structure and morphology of as-synthesized CNTs were characterized using SEM. The as-synthesized nanotubes were purified by acid and basic treatments in order to remove impurities such as amorphous carbon, graphite nanoparticles and metal catalysts. XRD and DTA/TG analyses showed that the amounts of by-products in the purified CNTs samples were reduced significantly. According to the observed results, ethylene is an active carbon source for growing high-density CNTs with high yield but more on alumina-supported catalysts than on their silica-supported counterparts. The last might be explained by SMSI formed in the case of alumina-supported catalysts, resulting in higher active phase dispersion.

scholarly journals Bromate Removal from Water Using Doped Iron Nanoparticles on Multiwalled Carbon Nanotubes (CNTS)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Aasem Zeino ◽  
Abdalla Abulkibash ◽  
Mazen Khaled ◽  
Muataz Atieh
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Iron Nanoparticles ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Transmission Electron

The raw carbon nanotubes (CNTs) were prepared by the floating catalyst chemical vapor deposition method. The raw carbon nanotubes were functionalized, impregnated with iron nanoparticles, and characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The three types of these multiwalled carbon nanotubes were applied as adsorbents for the removal of bromate from drinking water. The effects of the pH, the concentration ofBrO3-anion, the adsorbent dose, the contact time, and the coanions on the adsorption process have been investigated. The results concluded that the highest adsorption capacities were 0.3460 and 0.3220 mg/g through using CNTs-Fe and raw CNTs, respectively, at the same conditions. The results showed that the CNTs-Fe gives higher adsorption capacity compared with the raw CNTs and the functionalized CNTs. The presence of nitrate (NO3-) in the solution decreases the adsorption capacity of all CNTs compared with chloride (Cl-) associated with pH adjustment caused by nitric acid or hydrochloric acid, respectively. However, the adsorption of all MWNCTs types increases as the pH of solution decreases.

scholarly journals Enhancement of Photocatalytic Activity on TiO2-Nitrogen-Doped Carbon Nanotubes Nanocomposites

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lingling Wang ◽  
Long Shen ◽  
Yihuai Li ◽  
Luping Zhu ◽  
Jiaowen Shen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Organic Pollutant ◽  
Scanning Calorimetry ◽  
Nitrogen Doped ◽  
Photogenerated Electrons ◽  
Transmission Electron ◽  
Effective Transfer ◽  
Nitrogen Doped Carbon

TiO2-nitrogen-doped carbon nanotubes (TiO2-CNx) nanocomposites are successfully synthesized via a facile hydrothermal method. The prepared photocatalysts were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric and differential scanning calorimetry analyses (TGA-DSC). The results show that the TiO2nanoparticles with a narrow size of 7 nm are uniformly deposited on CNx. The photocatalytic activity of the nanocomposite was studied using methyl orange (MO) as a model organic pollutant. The experimental results revealed that the strong linkage between the CNx and TiO2played a significant role in improving photocatalytic activity. However, the mechanical process for CNx and TiO2mixtures showed lower activity than neat TiO2. Moreover, TiO2-CNx nanocomposites exhibit much higher photocatalytic activity than that of neat TiO2and TiO2-CNTs nanocomposites. The improved photodegradation performances are attributed to the suppressed recombination of electrons and holes caused by the effective transfer of photogenerated electrons from TiO2to CNx.

Lanthanum nickel alloy catalyzed growth of nitrogen-doped carbon nanotubes by chemical vapor deposition

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20554-20566 ◽  
Author(s):  
John Anthuvan Rajesh ◽  
Arumugam Pandurangan
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Nickel Alloy ◽  
Growth Mechanism ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon ◽  
Dissolution And Precipitation ◽  
Alloy Catalyst

CNTs doped with large amounts of nitrogen were produced on a LaNi5 alloy catalyst by CVD and its growth mechanism discussed on the basis of dissolution and precipitation mechanisms.

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