Use of Graphite Nanofibers as a Novel Catalyst Support Medium for Hydrogenation Reactions

1996 ◽  
Vol 454 ◽  
Author(s):  
C. Park ◽  
N. M. Rodriguez ◽  
R. T. K. Baker
Keyword(s):  
Carbon Nanofibers ◽  
Carbon Nanofiber ◽  
Catalyst Support ◽  
Catalytic Behavior ◽  
Graphite Nanofibers ◽  
Nickel Particles ◽  
Support Medium ◽  
Different Types ◽  
Hydrogenation Reactions ◽  
Novel Catalyst

ABSTRACTIn this investigation we elected to use the hydrogenation of 1-butene as probe reactions in an attempt to monitor any possible changes in catalytic behavior resulting from supporting 5 wt.% nickel on different types of carbon nanofibers compared to the performance of the same metal loading on more traditional carriers, including γ-Al2O3 and active carbon. In all cases the carbon nanofiber supported nickel particles are found to exhibit superior activity and significant changes in selectivity to that found from the same metal supported on traditional carriers.

The Impact of the Graphite Nanofiber Structure on the Behavior of Supported Nickel

1997 ◽  
Vol 497 ◽  
Author(s):  
C. Park ◽  
R. T. K. Baker
Keyword(s):  
Metal Particles ◽  
Unsaturated Aldehyde ◽  
Catalytic Behavior ◽  
Support Materials ◽  
Crotyl Alcohol ◽  
Nickel Particles ◽  
Different Types ◽  
Hydrogenation Reactions ◽  
The Impact ◽  
Hydrogenation Of Ethylene

ABSTRACTIn the current investigation we have used the hydrogenation of ethylene and crotonaldehyde as probe reactions in an attempt to follow any changes in catalytic behavior induced by supporting nickel on different types of graphite nanofiber support materials. The hydrogenation of the α,β-unsaturated aldehyde to the desired product, crotyl alcohol, is a particularly difficult task since there is a strong tendency to hydrogenate both the C=C and C=O in the reactant molecule. This study is designed to compare the catalytic behavior of the metal particles when dispersed on three types of nanofibers, where the orientation of the graphite platelets within the structures is significantly different in each case. The metal crystallites are located in such a manner that the majority of particles are in direct contact with graphite edge regions. For comparison purposes, the same set of hydrogenation reactions were carried out under similar conditions over γ-Al2O3 supported nickel particles.

Carbon Nanofibers: A Unique Catalyst Support Medium

1994 ◽  
Vol 98 (50) ◽  
pp. 13108-13111 ◽  
Author(s):  
Nelly M. Rodriguez ◽  
Myung-Soo Kim ◽  
R. Terry K. Baker
Keyword(s):  
Carbon Nanofibers ◽  
Catalyst Support ◽  
Support Medium

Carbon Nanofibers as a Novel Catalyst Support

1994 ◽  
Vol 368 ◽  
Author(s):  
Myung-Soo Kim ◽  
Nelly M. Rodriguez ◽  
R. Terry K. Baker
Keyword(s):  
Thermal Decomposition ◽  
Carbon Nanofibers ◽  
Active Carbon ◽  
Catalyst Support ◽  
Electrical Measurements ◽  
Surface Areas ◽  
Carbon And Graphite ◽  
Physical Form ◽  
Catalyst Systems ◽  
Novel Catalyst

ABSTRACTCatalytically grown carbon nanofibers have been prepared by the thermal decomposition of carbon containing gases over copper-nickel and iron surfaces. This material is found to be highly graphitic in nature when prepared from certain catalysts and gaseous reactants. In the as-grown state, carbon nanofibers have surface areas in the range 200 to 300 m2/g, and by following careful activation procedures this value can readily be increased to ˜700 m2/g. Electrical measurements indicate that the material has a conductivity approaching that of single crystal graphite. This material combines the attributes of active carbon and graphite and in addition, the physical form of carbon nanofibers offers some interesting opportunities for the design of unique catalyst systems.

Cabon Nanofibrous Materials Prepared from Electrospun Polyacrylonitrile Nanofibers for Hydrogen Storage

2004 ◽  
Vol 837 ◽  
Author(s):  
S. H. Park ◽  
B. C. Kim ◽  
S. M. Jo ◽  
D. Y. Kim ◽  
W. S. Lee
Keyword(s):  
Hydrogen Storage ◽  
Carbon Nanofibers ◽  
Carbon Nanofiber ◽  
Gravimetric Method ◽  
Carbonization Temperature ◽  
Magnetic Suspension ◽  
Graphite Nanofibers ◽  
Surface Areas ◽  
Amorphous Structures ◽  
Buoyancy Correction

ABSTRACTElectrospun PAN nanofibers were carbonized with or without iron(III) acetylacetonate to induce catalytic graphitization within the range of 900–1500°C, resulting in ultrafine carbon fibers with the diameter of about 90–300 nm. The structural properties and morphologies of the resulting carbon nanofibers were investigated using XRD, Raman IR, SEM, TEM, and surface area/pore analysis. The PAN-based carbon nanofibers carbonized without a catalyst had amorphous structures, with d002 = 0.37 nm, and smooth surfaces with very low surface areas of 22–31 m2/g. The carbonization of PAN-based nanofibers in the presence of the catalyst produced the graphite nanofibers (GNF) with d002 = 0.341 nm, indicating turbostrate structures. The graphite structures were grown by increasing the catalyst contents and the carbonization temperature. The hydrogen storage capacities of the aforementioned carbon nanofiber materials were evaluated through the gravimetric method using Magnetic Suspension Balance (MSB) at room temperature and at 100 bars. The storage data were obtained after the buoyancy correction. The CNFs showed hydrogen storage capacities of 0.16–0.50 wt.%, increasing with the increase of carbonization temperature, but that of the CNF at 1500°C was lowest. The hydrogen storage capacities of the GNFs with low surface areas of 100–250m2/g were 0.14–1.01 wt%.

scholarly journals Processing and Structure of Carbon Nanofiber Paper

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongfu Zhao ◽  
Jihua Gou ◽  
Aurangzeb Khan
Keyword(s):  
Carbon Nanofibers ◽  
Acid Treatment ◽  
Carbon Nanofiber ◽  
Essential Element ◽  
Process Conditions ◽  
Processing Conditions ◽  
Different Types ◽  
Design And Manufacture ◽  
Dispersion Quality

A unique concept of making nanocomposites from carbon nanofiber paper was explored in this study. The essential element of this method was to design and manufacture carbon nanofiber paper with well-controlled and optimized network structure of carbon nanofibers. In this study, carbon nanofiber paper was prepared under various processing conditions, including different types of carbon nanofibers, solvents, dispersants, and acid treatment. The morphologies of carbon nanofibers within the nanofiber paper were characterized with scanning electron microscopy (SEM). In addition, the bulk densities of carbon nanofiber papers were measured. It was found that the densities and network structures of carbon nanofiber paper correlated to the dispersion quality of carbon nanofibers within the paper, which was significantly affected by papermaking process conditions.

scholarly journals Characterization of Carbon Nanofibers Treated with Thermal Nitrogen as a Catalyst Support Using Point-of-Zero Charge Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Thien Duc Nguyen Van ◽  
Suriati Sufian ◽  
Nurlidia Mansor ◽  
Noorhana Yahya
Keyword(s):  
Carbon Nanofibers ◽  
Amorphous Carbon ◽  
Active Sites ◽  
Gas Flow ◽  
Carbon Nanofiber ◽  
Catalyst Support ◽  
Carbon Surface ◽  
Point Of Zero Charge ◽  
Zero Charge ◽  
Defect Sites

The chemical and physical purification of carbon nanofiber exposes more anchoring sites between meal precursors and carbon surface but thermal N2gas flow maintains the crystal’s structure as well as its defect and edge sites, referred to as active sites or anchoring sites. After calcination in nitrogen at 450°C, samples were characterized by Raman spectra X-ray diffraction, as well as thermogravimetric and nitrogen physisorption analyses. Results showed a relatively lower fraction of amorphous carbon to graphite, indicating a greater removal of amorphous carbon. Moreover, the disorder intensity of carbon nanofibers that were treated in N2flow rate of 1 L/min and 3 hours, called 1Gcom-3h sample, achieved far more defect sites compared with unmodified carbon nanofiber. In addition, the surface areas of mesoporous carbon nanofibers decreased over prolonged residence time. The carbon nanofiber support-metal cation interaction therefore improved the deposition of iron when the point-of-zero charge reading was greater than four.

Cytocompatibility of Carbon Nanofiber Materials for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Carbon Fiber ◽  
Surface Energy ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Carbon Nanofiber ◽  
Fiber Composite ◽  
Scar Tissue ◽  
Pc 12 Cells ◽  
Low Surface Energy ◽  
Poly Carbonate

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.

Cytocompatibility and Material Properties of Poly-carbonate Urethane/Carbon Nanofiber Composites for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Material Properties ◽  
Carbon Nanofiber ◽  
Scar Tissue ◽  
Tissue Response ◽  
Positive Interactions ◽  
Weight Percentage ◽  
Poly Carbonate

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.

scholarly journals A flexible and highly sensitive pressure sensor based on three-dimensional electrospun carbon nanofibers

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 13898-13905
Author(s):  
Chuan Cai ◽  
He Gong ◽  
Weiping Li ◽  
Feng Gao ◽  
Qiushi Jiang ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Pressure Sensor ◽  
Carbon Nanofiber ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Highly Sensitive ◽  
Sensitive Pressure

A three-dimensional electrospun carbon nanofiber network was used to measure press strains with high sensitivity.

scholarly journals Co9S8@carbon nanofiber as the high-performance anode for potassium-ion storage

RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15416-15421
Author(s):  
Wen Xin ◽  
Zhixuan Wei ◽  
Shiyu Yao ◽  
Nan Chen ◽  
Chunzhong Wang ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Volume Expansion ◽  
High Performance ◽  
Carbon Nanofiber ◽  
Potassium Ion ◽  
Rate Performance ◽  
Active Electrode ◽  
Fast Kinetics ◽  
Highly Active ◽  
Ion Storage

Co9S8@carbon nanofibers with boosted highly active electrode–electrolyte area, fast kinetics and controlled volume expansion show an excellent cycling and rate performance in potassium ion batteries.

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