Synthesis of Ni@MWCNTs Magnetic Nanocatalysts and their Catalytic Activity towards 4-Nitrophenol Reduction

2012 ◽  
Vol 531 ◽  
pp. 358-361 ◽  
Author(s):  
Ming Mei Zhang ◽  
Qian Sun ◽  
Ji Min Xie
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Average Particle Size ◽  
Chemical Vapor ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Ni Nanoparticles ◽  
Nitrophenol Reduction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A well-dispersed Ni nanoparticles on multi-walled carbon nanotubes (Ni@MWCNTs) was prepared by chemical vapor deposition (CVD) method using a vacuum quartz tube furnace at the temperature of 600°C. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were performed to characterize the synthesized catalyst. It shows an unfirom dispersion of Ni nanoparticles on MWCNTs with the average particle size of 8.6 nm. The as synthesized catalyst was applied in a redox reaction of 4-nitrophenol, which showed very high catalytic activity, stability and well conversion. The catalyst can be easily separated due to the magnetical performance

Ni/MWCNT-Supported Palladium Nanoparticles as Magnetic Catalysts for Selective Oxidation of Benzyl Alcohol

2013 ◽  
Vol 66 (5) ◽  
pp. 564 ◽  
Author(s):  
Mingmei Zhang ◽  
Qian Sun ◽  
Zaoxue Yan ◽  
Junjie Jing ◽  
Wei Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Benzyl Alcohol ◽  
Bimetallic Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Oxidation Of Benzyl Alcohol ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Well dispersed Pd@Ni bimetallic nanoparticles on multi-walled carbon nanotubes (Pd@Ni/MWCNT) are prepared and used as catalysts for the oxidation of benzyl alcohol. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, and X-ray diffraction were performed to characterise the synthesised catalyst. The results show a uniform dispersion of Pd@Ni nanoparticles on MWCNT with an average particle size of 4.0 nm. The as synthesised catalyst was applied to the oxidation of benzyl alcohol. A 99 % conversion of benzyl alcohol and a 98 % selectivity of benzaldehyde were achieved by using the Pd@Ni/MWCNT (Pd: 0.2 mmol) catalyst with water as a solvent and H2O2 as oxidant at 80°C. The catalytic activity of Pd@Ni/MWCNT towards benzyl alcohol is higher than that of a Pd/MWCNT catalyst at the same Pd loadings. The catalyst can be easily separated due to its magnetic properties.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

Electron Microscopy and Raman Characterization of Multi-Walled Carbon Nanotubes Grown by Chemical Vapor Deposition

2008 ◽  
Vol 14 (S2) ◽  
pp. 304-305
Author(s):  
M Ellis ◽  
T Jutarosaga ◽  
S Smith ◽  
Y Wei ◽  
S Seraphin
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
New Mexico ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Raman Characterization

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

In situ assembly of well-dispersed Ni nanoparticles on silica nanotubes and excellent catalytic activity in 4-nitrophenol reduction

Nanoscale ◽  
2014 ◽  
Vol 6 (19) ◽  
pp. 11181-11188 ◽  
Author(s):  
Shenghuan Zhang ◽  
Shili Gai ◽  
Fei He ◽  
Shujiang Ding ◽  
Lei Li ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Catalytic Activity ◽  
High Catalytic Activity ◽  
Ni Nanoparticles ◽  
Small Particle Size ◽  
Reduction Strategy ◽  
Nitrophenol Reduction ◽  
Nanotube Composites ◽  
Loading Amount

Ni nanoparticle/silica nanotube composites with small particle size, good dispersion and high loading amount of Ni NPs was synthesized using an in situ thermal decomposition and reduction strategy. The composite exhibited high catalytic activity and good stability in 4-NP reduction.

scholarly journals Preparation and Electrochemical Performance of a Graphene Cathode Catalyst Decorated With Pt by Prolysis

2022 ◽  
Vol 9 ◽  
Author(s):  
Xi Wang ◽  
Ying Ren ◽  
Ni Suo ◽  
Guifeng Zhang
Keyword(s):  
Catalytic Activity ◽  
Platinum Catalyst ◽  
Retention Rate ◽  
Average Particle Size ◽  
Technical Problem ◽  
Pt Catalyst ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Chloroplatinic Acid ◽  
Platinum Particles

For fuel cells, to produce high-quality and low-platinum catalyst is a pressing technical problem. In this study, graphene cathode catalysts with controllable platinum content were decorated by pyrolyzing chloroplatinic acid under various process parameters to obtain a high catalytic activity and durability. The results show that platinum particles generated by pyrolyzing chloroplatinic acid are uniformly loaded on graphene without agglomeration. The average particle size of platinum particles is about 2.12 nm. The oxygen reduction reaction catalytic activity of catalyst samples first increases, then decreases with increasing platinum loading in cyclic voltammetry and LSV. Compared with the commercial Pt/C (20 wt% Pt) catalyst, the initial potential and the current density retention rate of the catalyst decorated with 8% platinum are 55 mV and 23.7% higher, respectively. From i-t curves, it was found that the stability of the catalyst prepared in this paper was improved compared with the commercial Pt/C catalyst. The catalysts prepared in the present research exhibits superior catalytic activity and stability.

SYNTHESIS AND ELECTROCATALYSIS APPLICATION OF HYBRID PLATINUM/CERIUM OXIDE/MULTI-WALLED CARBON NANOTUBES

2011 ◽  
Vol 04 (03) ◽  
pp. 295-298 ◽  
Author(s):  
CHENG HAN CHEN ◽  
YUH-JING CHIOU ◽  
WEI JEN LIOU ◽  
WEI SYUAN LIN ◽  
HONG MING LIN ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cerium Oxide ◽  
Average Particle Size ◽  
Pt Nanoparticles ◽  
Pt Catalyst ◽  
Average Particle ◽  
Redox Peak ◽  
Multi Walled Carbon Nanotubes ◽  
Electro Oxidation ◽  
Walled Carbon Nanotubes

The hybrid nanomaterials of platinum/cerium oxide/multi-walled carbon nanotubes ( Pt/CeO2 /MWCNTs) are synthesized successfully via impregnation and polyol processes. MWCNTs serve as an excellent supporter where CeO2 nanoparticles are decorated with well-distributed Pt nanoparticles. Images show the average particle size of crystalline Pt and CeO2 on MWCNTs are 3–7 and 20–30 nm, respectively. In electrochemical reaction, the redox peak of Pt/CeO2 -700°C/MWCNTs reveals lower potential and higher current density in methanol electro-oxidation than those of other Pt -based ones. The study indicates that the cerium oxide in Pt/CeO2 -700°C/MWCNTs catalyst will enhance significantly the oxygen ions transportation between the interface of Pt and MWCNTs to eliminate the CO poison effect on Pt catalyst.

PdO nanoparticles enhancing the catalytic activity of Pd/carbon nanotubes for 4-nitrophenol reduction

RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27526-27532 ◽  
Author(s):  
Chunxia Wang ◽  
Fan Yang ◽  
Wang Yang ◽  
Liang Ren ◽  
Yunhan Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
One Pot ◽  
Plasma Method ◽  
Nitrophenol Reduction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this work, Pd/PdO nanoparticles (NPs) supported on oxidized multi-walled carbon nanotubes are prepared by a one-pot gas–liquid interfacial plasma method. The presence of PdO NPs significantly enhances the performance of the catalyst in the reduction of 4-nitrophenol.

Synthesis and Characteristics of Multi-Walled Carbon Nanotubes-Polyimide Nanocomposite Films

2008 ◽  
Vol 8 (5) ◽  
pp. 2671-2675 ◽  
Author(s):  
Mei-Hui Tsai ◽  
Dong-Sen Chen ◽  
Pei-Chun Chiang ◽  
Hsin-Chuan Lin ◽  
Jih-Mirn Jehng
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Nanocomposite Film ◽  
Chemical Vapor ◽  
Mechanical Analysis ◽  
Nanocomposite Films ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Polyimide Nanocomposite ◽  
Walled Carbon Nanotubes

The polyimide/multi-walled carbon nanotubes (PI/MWNTs) nanocomposite film has been successfully synthesized in this study. The source of MWNTs is prepared by chemical vapor deposition (CVD) method. Then the MWNTs are washed with acid for purification before being added into the polymer matrix. The acid-modified procedure aids in dispersing MWNTs in N,N-dimethylacetamide (DMAc) solvent. Based on the results of field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), the MWNTs are embedded in PI and well-dispersed within the PI matrix. The dynamic mechanical analysis (DMA) shows that the storage modulus of nanocomposite film is increased by 68% with the addition of 1 wt% MWNTs into PI. The nanocomposite films start to decompose at or above 400 °C and lose 5% of its weight at 545 °C according to thermogravimetric analysis (TGA). Meanwhile, the electrical conductivity of the nanocomposite film with 3 wt% MWNTs, is raised more than 10 orders of magnitude from 10−15 to 10−5 S/cm.

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