1) Nitrogen-containing carbon nanotubes were synthesized and used to support platinum nanoparticles as an alternative anode catalyst for direct methanol fuel cells.
2) The platinum nanoparticles were uniformly distributed on the nitrogen-containing carbon nanotubes with an average particle size of 3 nm.
3) Cyclic voltammetry studies showed that the platinum nanoparticles supported on nitrogen-containing carbon nanotubes had significantly higher catalytic activity for methanol oxidation compared to a conventional platinum on carbon catalyst.
Maiyalagan, Synthesis and electro catalytic activity of methanol oxidation on...kutty79
Template synthesis of various nitrogen containing carbon nanotubes using different nitrogen containing polymers and the variation of nitrogen
content in carbon nanotube (CNT) on the behaviour of supported Pt electrodes in the anodic oxidation of methanol in direct methanol fuel cells was
investigated. Characterizations of the as-prepared catalysts are investigated by electron microscopy and electrochemical analysis. The catalyst with
N-containing CNT as a support exhibits a higher catalytic activity than that carbon supported platinum electrode and CNT supported electrodes.
The N-containing CNT supported electrodes with 10.5% nitrogen content show a higher catalytic activity compared to other N-CNT supported
electrodes. This could be due to the existence of additional active sites on the surface of the N-containing CNT supported electrodes, which favours
better dispersion of Pt particles. Also, the strong metal-support interaction plays a major role in enhancing the catalytic activity for methanol
oxidation.
Visible light assisted photocatalytic reduction of CO2 using a graphene oxide...Pawan Kumar
A new heteroleptic ruthenium complex containing 2-thiophenyl benzimidazole ligands was synthesized using a microwave technique and was immobilized to graphene oxide via covalent attachment. The synthesized catalyst was used for the photoreduction of carbon dioxide under visible light irradiation without using a sacrificial agent, which gave 2050 μmol g−1 cat methanol after 24 h of irradiation
Vapor growth of binary and ternary phosphorus-based semiconductors into TiO2 ...Pawan Kumar
We report successful synthesis of low band gap inorganic polyphosphide and TiO2 heterostructures with the aid of short-way transport reactions. Binary and ternary polyphosphides (NaP7, SnIP, and (CuI)3P12) were successfully reacted and deposited into electrochemically fabricated TiO2 nanotubes. Employing vapor phase reaction deposition, the cavities of 100 μm long TiO2 nanotubes were infiltrated; approximately 50% of the nanotube arrays were estimated to be infiltrated in the case of NaP7. Intensive characterization of the hybrid materials with techniques including SEM, FIB, HR-TEM, Raman spectroscopy, XRD, and XPS proved the successful vapor phase deposition and synthesis of the substances on and inside the nanotubes. The polyphosphide@TiO2 hybrids exhibited superior water splitting performance compared to pristine materials and were found to be more active at higher wavelengths. SnIP@TiO2 emerged to be the most active among the polyphosphide@TiO2 materials. The improved photocatalytic performance might be due to Fermi level re-alignment and a lower charge transfer resistance which facilitated better charge separation from inorganic phosphides to TiO2.
Maiyalagan, Synthesis and electro catalytic activity of methanol oxidation on...kutty79
Template synthesis of various nitrogen containing carbon nanotubes using different nitrogen containing polymers and the variation of nitrogen
content in carbon nanotube (CNT) on the behaviour of supported Pt electrodes in the anodic oxidation of methanol in direct methanol fuel cells was
investigated. Characterizations of the as-prepared catalysts are investigated by electron microscopy and electrochemical analysis. The catalyst with
N-containing CNT as a support exhibits a higher catalytic activity than that carbon supported platinum electrode and CNT supported electrodes.
The N-containing CNT supported electrodes with 10.5% nitrogen content show a higher catalytic activity compared to other N-CNT supported
electrodes. This could be due to the existence of additional active sites on the surface of the N-containing CNT supported electrodes, which favours
better dispersion of Pt particles. Also, the strong metal-support interaction plays a major role in enhancing the catalytic activity for methanol
oxidation.
Visible light assisted photocatalytic reduction of CO2 using a graphene oxide...Pawan Kumar
A new heteroleptic ruthenium complex containing 2-thiophenyl benzimidazole ligands was synthesized using a microwave technique and was immobilized to graphene oxide via covalent attachment. The synthesized catalyst was used for the photoreduction of carbon dioxide under visible light irradiation without using a sacrificial agent, which gave 2050 μmol g−1 cat methanol after 24 h of irradiation
Vapor growth of binary and ternary phosphorus-based semiconductors into TiO2 ...Pawan Kumar
We report successful synthesis of low band gap inorganic polyphosphide and TiO2 heterostructures with the aid of short-way transport reactions. Binary and ternary polyphosphides (NaP7, SnIP, and (CuI)3P12) were successfully reacted and deposited into electrochemically fabricated TiO2 nanotubes. Employing vapor phase reaction deposition, the cavities of 100 μm long TiO2 nanotubes were infiltrated; approximately 50% of the nanotube arrays were estimated to be infiltrated in the case of NaP7. Intensive characterization of the hybrid materials with techniques including SEM, FIB, HR-TEM, Raman spectroscopy, XRD, and XPS proved the successful vapor phase deposition and synthesis of the substances on and inside the nanotubes. The polyphosphide@TiO2 hybrids exhibited superior water splitting performance compared to pristine materials and were found to be more active at higher wavelengths. SnIP@TiO2 emerged to be the most active among the polyphosphide@TiO2 materials. The improved photocatalytic performance might be due to Fermi level re-alignment and a lower charge transfer resistance which facilitated better charge separation from inorganic phosphides to TiO2.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
NO2 Gas Sensing Properties of Carbon Films Fabricated by Arc Discharge Methan...TELKOMNIKA JOURNAL
In this work, a set of experiments has been conducted using arc discharge Methane
decomposition attempting to obtain carbonaceous materials (C-strands) formed between graphite
electrodes. The current-voltage (I-V) characteristics of the fabricated C-strands have been investigated in
the presence and absence of two different gases, NO2 and CO2. The results reveal that the current
passing through the carbon films increases when the concentrations of gases are increased from 200 to
800 ppm. This phenomenon is a result of conductance changes and can be employed in sensing
applications such as gas sensors.
Oxidized multi walled carbon nanotubes for improving the electrocatalytic act...Iranian Chemical Society
In the present paper, the use of a novel carbon paste electrode modified by 7,8-dihydroxy-3,3,6-trimethyl-3,4-dihydrodibenzo[b,d]furan-1(2H)-one (DTD) and oxidized multi-walled carbon nanotubes (OCNTs) is described for determination of levodopa (LD), acetaminophen (AC) and tryptophan (Trp) by a simple and rapid method. At first, the electrochemical behavior of DTD is studied, then, the mediated oxidation of LD at the modified electrode is investigated. At the optimum pH of 7.4, the oxidation of LD occurs at a potential about 330 mV less positive than that of an unmodified carbon paste electrode. Based on differential pulse voltammetry (DPV), the oxidation current of LD exhibits a linear range between 1.0 and 2000.0 μM of LD with a detection limit (3σ) of 0.36 μM. DPV was also used for simultaneous determination of LD, AC and Trp at the modified electrode. Finally, the proposed electrochemical sensor was used for determinations of these substances in human serum sample.
Low Cost Synthesis of Single Walled Carbon Nanotubes from Coal Tar Using Arc ...IOSRJAP
There are various methods such as arc discharge, laser ablation, chemical vapour deposition (CVD), template-directed synthesis for the growth of CNTs in the presence of catalyst particles. The production of carbon nanotubes in large quantities is possible with inexpensive coal as the starting carbon source by the arc discharge technique. It is found that a large amount of carbon nanotubes of good quality can be obtained in the cathode deposits in which carbon nanotubes are present in nest-like bundles. For more than two decades, now, there has been extensive research on the production of carbon nanotubes (CNT) and optimization of its manufacture for the industrial applications. It is believed that they are the strong enough but most flexible materials known to mankind. They have potential to take part in new nanofabricated materials. It is known that, carbon nanotubes could behave as the ultimate one-dimensional material with remarkable mechanical properties. Moreover, carbon nanotubes exhibit strong electrical and thermal conducting properties. This paper primarily concentrates on the optimising such parameters related to the mass production of the product. It has been shown through Simplex process that based on the cost of the SWNT obtained by the arc discharge technique, the voltage and the current should lie in the range of 30 - 42 V and 49 - 66 A respectively. Any combination above the given values will lead to a power consumption cost beyond the final product cost, in turn leading to infeasibility of the process. Strong expectations exist for future use of carbon nanotubes as composite materials in a large number of industries. Production cost and control of the purity and properties of such materials will influence the impacts nanotubes on the chemical, computer and construction industries. Coal properties in this case are also important. Weak bonds and mineral matter in the coal play an important role in the formation of the nanotubes
This work studied the effect of applying pulse current
(ton=off=1s) on the electrodeposition of silver nanoparticles on
carbon sphere surface as a substrate. The electrolyte is made of 0.1
M KNO3, 0.1 M KCN and 0.01M AgNO3. The pH value has been
adjusted in the alkaline region of 9.1 with the help of K(NO3)
addition. Experiments were carried out at room temperature for
periods up to 12 minutes. The cell is fitted with a mechanical stirrer
to keep the electrolyte in a dynamic state. Product(s) was
characterized with the help of SEM and EDX and field emission.
Results obtained show that silver nanoparticles has successfully
electrodeposited under pulse current conditions with a particle size
of 100–400 nm after 2 minutes. Deposition takes place on certain
accessible sites of the carbon surface of the substrate forming a
monolayer of scattered silver nanoparticles. Formation of macro
particles with larger diameter and multilayer in thickness takes
place with continuous deposition of silver nanoparticles on the
formerly deposited silver. Pulse current helps management of the
monolayer deposition as compared to the steady DC application
with respect to particle diameter and number of layers.
Maiyalagan,Template synthesis and characterization of well aligned nitrogen c...kutty79
The synthesis of well-aligned nitrogen containing carbon nanotubes by pyrolysis of polyvinyl pyrrolidone (PVP) on alumina membrane
template is described. The nanotubes were characterized by elemental analysis, electron microscopic analyses, Raman, IR and X-ray photoelectron
(XPS) spectroscopic techniques. SEM, transmission electron microscopy (TEM) and AFM images reveal the hollow structures and
vertically aligned features of the nanotubes. Raman spectrum shows the characteristic bands at 1290 cm−1 (D-band) and 1590 cm−1 (G-band).
IR spectral bands indicated the characteristic C–N bonds in carbon nanotubes. This confirms the presence of nitrogen atoms in the carbon
framework. The XPS and elemental analyses further indicate significant amount of nitrogen in the nanotubes. IR, elemental and XPS analyses
clearly provide evidence for the presence of nitrogen in carbon nanotubes.
Maiyalagan,Electrochemical oxidation of methanol on pt v2 o5–c composite cata...kutty79
Platinum nanoparticles have been supported on V2O5–C composite through the reduction of chloroplatinic
acid with formaldehyde. The catalyst was characterized by X-ray diffraction and transmission electron
microscopy. Catalytic activity and stability for the oxidation of methanol were studied by using
cyclic voltammetry and chronoamperometry. Pt/V2O5–C composite anode catalyst on glassy carbon electrode
show higher electro-catalytic activity for the oxidation of methanol. High electro-catalytic activities
and good stabilities could be attributed to the synergistic effect between Pt and V2O5, avoiding the electrodes
being poisoned.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
NO2 Gas Sensing Properties of Carbon Films Fabricated by Arc Discharge Methan...TELKOMNIKA JOURNAL
In this work, a set of experiments has been conducted using arc discharge Methane
decomposition attempting to obtain carbonaceous materials (C-strands) formed between graphite
electrodes. The current-voltage (I-V) characteristics of the fabricated C-strands have been investigated in
the presence and absence of two different gases, NO2 and CO2. The results reveal that the current
passing through the carbon films increases when the concentrations of gases are increased from 200 to
800 ppm. This phenomenon is a result of conductance changes and can be employed in sensing
applications such as gas sensors.
Oxidized multi walled carbon nanotubes for improving the electrocatalytic act...Iranian Chemical Society
In the present paper, the use of a novel carbon paste electrode modified by 7,8-dihydroxy-3,3,6-trimethyl-3,4-dihydrodibenzo[b,d]furan-1(2H)-one (DTD) and oxidized multi-walled carbon nanotubes (OCNTs) is described for determination of levodopa (LD), acetaminophen (AC) and tryptophan (Trp) by a simple and rapid method. At first, the electrochemical behavior of DTD is studied, then, the mediated oxidation of LD at the modified electrode is investigated. At the optimum pH of 7.4, the oxidation of LD occurs at a potential about 330 mV less positive than that of an unmodified carbon paste electrode. Based on differential pulse voltammetry (DPV), the oxidation current of LD exhibits a linear range between 1.0 and 2000.0 μM of LD with a detection limit (3σ) of 0.36 μM. DPV was also used for simultaneous determination of LD, AC and Trp at the modified electrode. Finally, the proposed electrochemical sensor was used for determinations of these substances in human serum sample.
Low Cost Synthesis of Single Walled Carbon Nanotubes from Coal Tar Using Arc ...IOSRJAP
There are various methods such as arc discharge, laser ablation, chemical vapour deposition (CVD), template-directed synthesis for the growth of CNTs in the presence of catalyst particles. The production of carbon nanotubes in large quantities is possible with inexpensive coal as the starting carbon source by the arc discharge technique. It is found that a large amount of carbon nanotubes of good quality can be obtained in the cathode deposits in which carbon nanotubes are present in nest-like bundles. For more than two decades, now, there has been extensive research on the production of carbon nanotubes (CNT) and optimization of its manufacture for the industrial applications. It is believed that they are the strong enough but most flexible materials known to mankind. They have potential to take part in new nanofabricated materials. It is known that, carbon nanotubes could behave as the ultimate one-dimensional material with remarkable mechanical properties. Moreover, carbon nanotubes exhibit strong electrical and thermal conducting properties. This paper primarily concentrates on the optimising such parameters related to the mass production of the product. It has been shown through Simplex process that based on the cost of the SWNT obtained by the arc discharge technique, the voltage and the current should lie in the range of 30 - 42 V and 49 - 66 A respectively. Any combination above the given values will lead to a power consumption cost beyond the final product cost, in turn leading to infeasibility of the process. Strong expectations exist for future use of carbon nanotubes as composite materials in a large number of industries. Production cost and control of the purity and properties of such materials will influence the impacts nanotubes on the chemical, computer and construction industries. Coal properties in this case are also important. Weak bonds and mineral matter in the coal play an important role in the formation of the nanotubes
This work studied the effect of applying pulse current
(ton=off=1s) on the electrodeposition of silver nanoparticles on
carbon sphere surface as a substrate. The electrolyte is made of 0.1
M KNO3, 0.1 M KCN and 0.01M AgNO3. The pH value has been
adjusted in the alkaline region of 9.1 with the help of K(NO3)
addition. Experiments were carried out at room temperature for
periods up to 12 minutes. The cell is fitted with a mechanical stirrer
to keep the electrolyte in a dynamic state. Product(s) was
characterized with the help of SEM and EDX and field emission.
Results obtained show that silver nanoparticles has successfully
electrodeposited under pulse current conditions with a particle size
of 100–400 nm after 2 minutes. Deposition takes place on certain
accessible sites of the carbon surface of the substrate forming a
monolayer of scattered silver nanoparticles. Formation of macro
particles with larger diameter and multilayer in thickness takes
place with continuous deposition of silver nanoparticles on the
formerly deposited silver. Pulse current helps management of the
monolayer deposition as compared to the steady DC application
with respect to particle diameter and number of layers.
Maiyalagan,Template synthesis and characterization of well aligned nitrogen c...kutty79
The synthesis of well-aligned nitrogen containing carbon nanotubes by pyrolysis of polyvinyl pyrrolidone (PVP) on alumina membrane
template is described. The nanotubes were characterized by elemental analysis, electron microscopic analyses, Raman, IR and X-ray photoelectron
(XPS) spectroscopic techniques. SEM, transmission electron microscopy (TEM) and AFM images reveal the hollow structures and
vertically aligned features of the nanotubes. Raman spectrum shows the characteristic bands at 1290 cm−1 (D-band) and 1590 cm−1 (G-band).
IR spectral bands indicated the characteristic C–N bonds in carbon nanotubes. This confirms the presence of nitrogen atoms in the carbon
framework. The XPS and elemental analyses further indicate significant amount of nitrogen in the nanotubes. IR, elemental and XPS analyses
clearly provide evidence for the presence of nitrogen in carbon nanotubes.
Maiyalagan,Electrochemical oxidation of methanol on pt v2 o5–c composite cata...kutty79
Platinum nanoparticles have been supported on V2O5–C composite through the reduction of chloroplatinic
acid with formaldehyde. The catalyst was characterized by X-ray diffraction and transmission electron
microscopy. Catalytic activity and stability for the oxidation of methanol were studied by using
cyclic voltammetry and chronoamperometry. Pt/V2O5–C composite anode catalyst on glassy carbon electrode
show higher electro-catalytic activity for the oxidation of methanol. High electro-catalytic activities
and good stabilities could be attributed to the synergistic effect between Pt and V2O5, avoiding the electrodes
being poisoned.
Synthesis of MWNTs, DWNTs and SWNTs buckypaper using triton x 100. and compar...Awad Albalwi
In this study buckypaper of MWNTs, DWNTs and SWNT have been synthesised using filtration of carbon nanotubes dispersed in 1% TritonX 100 as solvents. Dispersions were generated by pulse sonication of each single wall carbon nanotubes (SWNTs) , Double wall carbon nanotubes (DWNTs) and Multi wall carbon nanotubes in TritonX solvent. Fist, sonication times were investigated for these CNTs to determine the optimum conditions for generating stable dispersions of carbon nanotubes. It was found that optimal dispersions could be generated using Trion X-100 solvent with all these carbon nanotube by using 30minute periods of pulse sonication. The Three buckypapers of MWNTs, DWNTs and SWNTs were produced by filtering dispersions of carbon nanotubes which had undergone 30 minutes of pulse sonication in TritonX100. Conductivity and measurements of the three buckypaper (SWNT,DWNT&MWNT) samples yielded average values of 14.24 , 23 and 19 Scm-1 respectively. Mechanical measurements were determined successfully . Homogeneity in the produced buckypapers were investigated confirming by scanning electron microscopy .
Dynamic and Equilibrium Studies on the sorption of Basic dye (Basic Brown 4) ...madlovescience
Dynamic and Equilibrium Studies on the sorption of Basic dye (Basic Brown 4) onto Multi-walled Carbon Nanotubes Prepared from Renewable Carbon Precursors
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Nitrogen containing carbon nanotubes as supports for pt–alternate anodes for fuel cell applications
1. Electrochemistry Communications 7 (2005) 905–912
www.elsevier.com/locate/elecom
Nitrogen containing carbon nanotubes as supports for
Pt – Alternate anodes for fuel cell applications
T. Maiyalagan, B. Viswanathan *, U.V. Varadaraju
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
Received 7 June 2005; accepted 7 July 2005
Available online 8 August 2005
Abstract
Aligned nitrogen containing carbon nanotubes have been synthesized using Anodisc alumina membrane as template. Highly dispersed platinum nanoparticles have been supported on the nitrogen containing carbon nanotubes. Nitrogen containing carbon
nanotubes as platinum catalyst supports were characterized by electron microscopic technique and electrochemical analysis. The
EDX patterns show the presence of Pt and the micrograph of TEM shows that the Pt particles are uniformly distributed on the
surface of the nitrogen containing carbon nanotube with an average particle size of 3 nm. Cyclic voltammetry studies revealed a
higher catalytic activity of the nitrogen containing carbon nanotube supported Pt catalysts.
Ó 2005 Elsevier B.V. All rights reserved.
Keywords: Nitrogen containing carbon nanotubes; Template synthesis; Alumina template; Catalyst support; Methanol oxidation
1. Introduction
Since the last decade, fuel cells have been receiving an
increased attention due to the depletion of fossil fuels
and rising environmental pollution. Fuel cells have been
demonstrated as interesting and very promising alternatives to solve the problem of clean electric power generation with high efficiency. Among the different types of
fuel cells, direct methanol fuel cells (DMFCs) are excellent power sources for portable applications owing to its
high energy density, ease of handling liquid fuel, low
operating temperatures (60–100 °C) and quick start up
[1,2]. Furthermore, methanol fuel cell seems to be highly
promising for large-scale commercialization in contrast
to hydrogen-fed cells, especially in transportation [3].
The limitation of methanol fuel cell system is due to
low catalytic activity of the electrodes, especially the anodes and at present, there is no practical alternative to
*
Corresponding author. Tel.: +91 044 22574200; fax: +91 44
22574202.
E-mail address: bvnathan@iitm.ac.in (B. Viswanathan).
1388-2481/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.elecom.2005.07.007
Pt based catalysts. High noble metal loadings on the
electrode [4,5] and the use of perfluorosulfonic acid
membranes significantly contribute to the cost of the devices. An efficient way to decrease the loadings of precious platinum metal catalysts and higher utilization of
Pt particles is by better dispersion of the desired metal
on the suitable support [6]. In general, small particle size
and high dispersion of platinum on the support will result in high electrocatalytic activity. Carbon materials
possess suitable properties for the design of electrodes
in electrochemical devices. Carbon is an ideal material
for supporting nano-sized metallic particles in the electrode for fuel cell applications. No other material except
carbon material has the essential properties of electronic
conductivity, corrosion resistance, surface properties,
and the low cost required for the commercialization of
fuel cells. In general, the conventional supports namely
carbon black is used for the dispersion of Pt particles [7].
The appearance of novel carbon support materials,
such as graphite nanofibers (GNFs) [8,9], carbon nanotubes (CNTs) [10–17], carbon nanohorns [18], and carbon nanocoils [19–22], provides new opportunities of
2. 906
T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
carbon supports for fuel cell applications. Bessel et al. [8]
and Steigerwalt et al. [9] used GNFs as supports for Pt
and Pt–Ru alloy electrocatalysts and observed better
activity for methanol oxidation. The high electronic
conductivity of GNFs and the specific crystallographic
orientation of the metal particles resulting from wellordered GNF support were believed to be the important
factors for the observed enhanced electrocatalytic activity. The morphology and the nature of the functional
groups of the support influence the activity of fuel cell
electrocatalyts [23–26]. Carbon with sulphur or nitrogen
based functionality [25], can influence the activity of the
catalyst.
The present report focuses on the efforts undertaken
to develop unconventional supports based platinum
catalysts for methanol oxidation. Nitrogen containing
carbon nanotubes were used to disperse the platinum
particles effectively without sintering and to increase
the catalytic activity for methanol oxidation. The tubular morphology and the nitrogen functionality of the
support have influence on the dispersion as well as
the stability of the electrode. In this communication
the preparation of highly dispersed platinum supported
on nitrogen containing carbon nanotubes, the evaluation of the activity for the methanol oxidation of these
electrodes and comparison with the activity of conventional electrodes are reported.
alumina template by wetting method [28]. After
complete solvent evaporation, the membrane was placed
in a quartz tube (30 cm length, 3.0 cm diameter), kept in
a tubular furnace and carbonized at 1173 K under Ar
gas flow. After 3 h of carbonization, the quartz tube
was cooled to room temperature. The resulting template
with carbon–nitrogen composite was immersed in 48%
HF at room temperature for 24 h to remove the alumina
template and the nitrogen containing CNTs were
obtained as an insoluble fraction. The nanotubes were
then washed with distilled water to remove the residual
HF and dried at 393 K.
2.3. Loading of Pt catalyst inside nanotube
Platinum nanoclusters were loaded inside the N-CNT
as follows; the C/alumina composite obtained (before
the dissolution of template membrane) was immersed
in 73 mM H2PtCl6 (aq) for 12 h. After immersion, the
membrane was dried in air and the ions were reduced
to the corresponding metal(s) by a 3 h exposure to flowing H2 gas at 823 K. The underlying alumina was then
dissolved by immersing the composite in 48% HF for
24 h. This procedure resulted in the formation of Pt
nanocluster loaded N-CNT and the complete removal
of fluorine and aluminum was confirmed by EDX
analysis.
2.4. Preparation of working electrode
2. Experimental
2.1. Materials
All the chemicals used were of analytical grade. Polyvinyl pyrrolidone (Sisco Research Laboratories, India),
dichloromethane and concentrated HF (both from
Merck) were used. Hexachloroplatinic acid was obtained from Aldrich. 20 wt% Pt/Vulcan carbons were
procured from E-TEK. Methanol and sulphuric acid
were obtained from Fischer chemicals. The alumina
template membranes (Anodisc 47) with 200 nm diameter
pores were obtained from Whatman Corp. Nafion
5 wt% solution was obtained from Dupont and was used
as received.
2.2. Synthesis of nitrogen containing carbon nanotubes
Pyrolysis of nitrogen containing polymers is a facile
method for the preparation of carbon nanotube materials containing nitrogen substitution in the carbon framework. Nitrogen containing carbon nanotubes were
synthesized by impregnating polyvinylpyrrolidone
(PVP) inside the alumina membrane template and subsequent carbonization of the polymer [27]. Polyvinylpyrrolidone (PVP – 5 g) was dissolved in dichloromethane
(20 ml) and impregnated directly in the pores of the
Glassy carbon (GC) (Bas electrode, 0.07 cm2) was
polished to a mirror finish with 0.05 m alumina suspensions before each experiment and served as an underlying substrate of the working electrode. In order to
prepare the composite electrode, the nanotubes were
dispersed ultrasonically in water at a concentration of
1 mg mlÀ1 and 20 ll aliquot was transferred on to a
polished glassy carbon substrate. After the evaporation
of water, the resulting thin catalyst film was covered
with 5 wt% Nafion solution. Then the electrode was
dried at 353 K and used as the working electrode.
2.5. Characterization methods
The chemical composition of the nanotubes was
determined by elemental analysis using Hereaus CHN
analyzer after the removal of alumina template. The
scanning electron micrographs were obtained using
JEOL JSM-840 model, working at 15 keV. The nanotubes were sonicated in acetone for 20 min and then
were dropped on the cleaned Si substrates. The AFM
imaging was performed in air using the Nanoscope IIIA
atomic force microscope (Digital Instruments, St. Barbara, CA) operated in contact mode. For transmission
electron microscopic studies, the nanotubes dispersed
in ethanol were placed on the copper grid and the
3. T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
images were obtained using Phillips 420 model, operating at 120 keV.
2.6. Electrochemical measurements
All electrochemical studies were carried out using a
BAS 100 electrochemical analyzer. A conventional
three-electrode cell consisting of the GC (0.07 cm2)
working electrode, Pt plate (5 cm2) as counter electrode
and Ag/AgCl reference electrode were used for the cyclic
voltammetry (CV) studies. The CV experiments were
performed using 1 M H2SO4 solution in the absence
and presence of 1 M CH3OH at a scan rate of
50 mV sÀ1. All the solutions were prepared by using ultra pure water (Millipore, 18 MX). The electrolytes were
degassed with nitrogen gas before the electrochemical
measurements.
3. Results and discussion
Elemental analysis was conducted to examine
whether nitrogen has really entered the carbon nanotube
framework. It has been found that the samples prepared
contained about 87.2% carbon and 6.6% nitrogen (w/w).
The SEM images of the nitrogen containing carbon
nanotubes support are shown in Fig. 1(a)–(c). Top view
of the vertically aligned nitrogen containing carbon
907
nanotubes is shown in Fig. 1(a). Fig. 1(b) shows lateral
view of the nitrogen containing carbon nanotubes with
low magnification and Fig. 1(c) shows lateral view of
the nitrogen containing carbon nanotubes with high
magnification. The hollow structure and well alignment
of the nitrogen containing carbon nanotubes have been
identified by SEM.
AFM images of the nitrogen containing carbon nanotubes deposited on a silicon substrate are shown in
Fig. 2. The AFM tip was carefully scanned across the
tube surface in a direction perpendicular to the tube
axis. From the AFM images, it is inferred that a part
of the long nanotube is appearing to be cylindrical in
shape and is found to be terminated by a symmetric
hemispherical cap. Because of the finite size of the
AFM tip, convolution between the blunt AFM tip and
the tube body will be giving rise to an apparently greater
lateral dimension than the actual diameter of the tube
[29].
The TEM images are shown in Fig. 3(a)–(c). The
open end of the tubes observed by TEM shows that
the nanotubes are hollow and the outer diameter of
the nanotube closely match with the pore diameter of
template used, with a diameter of 200 nm and a length
of approx. 40–50 lm. It is evident from the micrographs
that there is no amorphous material present in the nanotube. Fig. 3(c) shows the TEM image of Pt nanoparticles
filled carbon nanotubes. TEM pictures reveal that the Pt
Fig. 1. SEM images of the nitrogen containing carbon nanotubes: (a) the top view of the nanotubes; (b) side view of the vertically aligned nanotubes
and (c) high magnification lateral view of the nanotubes.
4. 908
T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
Fig. 2. AFM image of the nitrogen containing carbon nanotubes.
Fig. 3. TEM images of the nitrogen containing carbon nanotubes: (a) at lower magnification; (b) at higher magnification image of the individual
nanotube (an arrow indicating the open end of the tube) and (c) Pt filled nitrogen containing carbon nanotubes.
5. T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
particles have been homogeneously dispersed on the
nanotubes and particle sizes were found to be around
3 nm. The optimal Pt particle size for reactions in the
H2/O2 fuel cell is 3 nm [30]. The importance of the Pt
particle size on the activity for methanol oxidation is
due to the structure sensitive nature of the reaction
and the fact that particles with different sizes will
have different dominant crystal planes and hence the different intercrystallite distances, which might influence
methanol adsorption. The commercial Pt/C has a very
high specific surface area but contributed mostly by
micropores less than 1 nm and are therefore more difficult to be fully accessible. It has been reported that the
mean value of particle size for 20% Pt/Vulcan
(E-TEK) catalyst was 2.6 nm [31]. The EDX pattern of
the as synthesized catalyst shows the presence of Pt
particles in the carbon nanotubes and also the complete
removal of fluorine and aluminum has also been
confirmed in Fig. 4. It has been reported that the
electronic and physical structures of a Pt particle
deposited on carbon differ from those of the bulk Pt.
The electronic change in Pt/C is considered as a result
of functional groups of the carbon support that might
influence the electronic structure of Pt particulate
[32–36]. The nitrogen functional group on the carbon
nanotubes surface intensifies the electron withdrawing
effect against Pt and the decreased electron density of
platinum facilitate oxidation of methanol.
Fig. 5(a)–(c) shows the cyclic voltammogram of
methanol oxidation. Fig. 5(c) shows the cyclic voltammogram of Pt/N-CNT electrode in 1 M H2SO4/1 M
CH3OH run at a scan rate of 50 mV sÀ1. The electrocatalytic activity of methanol oxidation at the Pt/N-CNT
electrodes was evaluated and compared with that of
the conventional electrodes. During the anodic scan,
909
the current increases quickly due to dehydrogenation
of methanol followed by the oxidation of absorbed
methanol residues and reaches a maximum in the potential range between 0.8 and 1.0 V vs. Ag/AgCl. In the
cathodic scan, the re-oxidation of methanol is clearly
observed due to the reduction of oxide of platinum.
Electrocatalytic activity of methanol oxidation has been
found to be strongly influenced by the metal dispersion.
Pure Pt electrode shows an activity of 0.167 mA cmÀ2.
The Pt/N-CNT shows a higher activity of 13.3 mA cmÀ2
where as conventional 20% Pt/Vulcan (E-TEK)
electrode shows less activity of 1.3 mA cmÀ2 compared
to nitrogen containing carbon nanotube supported
electrode. The nitrogen containing carbon nanotube
supported electrodes shows a ten fold increase in the
catalytic activity compared to the E-TEK electrode.
The Pt/N-CNT electrode showed higher electrocatalytic
activity for methanol oxidation than commercial
Pt/Vulcan (E-TEK) electrode. The anodic current
density of Pt/N-CNT electrode is found to be higher
than that of Pt/Vulcan (E-TEK) electrode, which indicates that the catalyst prepared with nitrogen containing
carbon nanotubes as the support has excellent catalytic
activity on methanol electrooxidation.
The onset potential and the forward-scan peak current
density for the different electrodes are given in Table 1.
The onset potential of methanol oxidation at nitrogen
containing carbon nanotube supported catalysts occurs
at 0.22 V, which is relatively more negative to that of
the other catalysts. This may be attributed to the high dispersion of platinum catalysts and the nitrogen functional
groups on its surface. The higher electrocatalytic activity
of the nitrogen containing carbon nanotube supported
electrode is due to higher dispersion and a good interaction between the support and the Pt particles The Vulcan
Fig. 4. EDX pattern of Pt/N-CNT electrode.
6. 910
T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
Fig. 5. Cyclic voltammograms of (a) pure Pt; (b) Pt/Vulcan (E-TEK) and (c) Pt/N-CNT in 1 M H2SO4/1 M CH3OH run at 50 mV sÀ1.
Table 1
Electrochemical parameters for methanol oxidation on the various
electrodes
Electrocatalyst
Methanol oxidation
onset potential (V)
vs. Ag/AgCl
Forward peak current
density (mA cmÀ2)
Bulk Pt
20% Pt/C (E-TEK)
Pt/N-CNT
0.4
0.45
0.22
0.167
1.3
13.3
carbon support has randomly distributed pores of varying sizes which may make fuel and product diffusion
difficult whereas the tubular three-dimensional morphology of the nitrogen containing carbon nanotubes makes
the fuel diffusion easier. The Vulcan carbon contains high
levels of sulfur (ca. 5000 ppm or greater), which could
potentially poison the fuel-cell electrocatalysts [37].
Nitrogen containing carbon nanotubes used in this study
contains heterocyclic nitrogen so that it preferentially attaches the Pt particles. The selective attachment of Au
nanoparticles on nitrogen doped carbon nanotubes has
also been reported [38]. All these results indicate that
the nitrogen functionality on CNT influences the
catalytic activity of the catalyst. The enhanced electrocatalytic effect of the nitrogen containing carbon nanotube
supported electrodes could also be partly due to the
following factors which require further investigation:
(1) higher dispersion on the nitrogen containing carbon
nanotube support increases the availability of an
enhanced electrochemically active surface area, (2)
appearance of the specific active sites at the metal–
support boundary and, (3) strong metal–support
interaction.
Long-term stability is important for practical applications. Fig. 6 shows the current density–time plots of various electrodes in 1 M H2SO4 and 1 M CH3OH at 0.6 V.
The performance of Pt electrodes was found to be poor
compared to the E-TEK and Pt/N-CNT electrode. The
nitrogen containing carbon nanotube electrodes are the
most stable for direct methanol oxidation. The increasing order of stability of various electrodes is; Pt < Pt/
Vulcan (E-TEK) < Pt/N-CNT. We are currently investigating whether nitrogen has a catalytic role that contrib-
7. T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
Fig. 6. Current density vs. time curves at (a) Pt/N-CNT; (b) Pt/Vulcan
(E-TEK) and (c) Pt measured in 1 M H2SO4 + 1 M CH3OH. The
potential was stepped from the rest potential to 0.6 V vs. Ag/AgCl.
utes to the observed enhancement in the methanol oxidation. Recent experiments conducted in our laboratory
on Pt supported N-doped and undoped CNTs reveal the
importance of nitrogen functionalities on methanol oxidation activity [39].
In summary, it is reported platinum catalysts are
highly dispersed on the surface of well-aligned
nitrogen containing carbon nanotube. The tubular
morphology and the nitrogen functionality favour
dispersion of the Pt particles. The electrocatalytic
properties of Pt particles supported on the threedimensional nitrogen containing carbon nanotube
electrode shows higher catalytic activity for methanol
oxidation than the commercial E-TEK electrode,
which implies that the well-aligned nitrogen containing
carbon nanotube arrays have good potential
application as a catalyst support in direct methanol
fuel cells.
Acknowledgements
We thank the Council of Scientific and Industrial Research (CSIR), India, for a senior research fellowship to
one of the authors T. Maiyalagan.
References
[1] M.P. Hogarth, G.A. Hards, Platinum Met. Rev. 40 (1996) 150.
[2] T.R. Ralph, Platinum Met. Rev. 41 (1997) 102.
[3] B.D. McNicol, D.A.J. Rand, K.R. Williams, J. Power Sources 83
(2001) 47.
[4] A. Hamnett, Catal. Today 38 (1997) 445.
[5] S. Wasmus, A. Kuver, J. Electroanal. Chem. 461 (1999) 14.
911
[6] T. Matsumoto, T. Komatsu, K. Arai, T. Yamazaki, M. Kijima,
H. Shimizu, Y. Takasawa, J. Nakamura, Chem. Commun. 7
(2004) 840.
[7] K. Kinoshita, Carbon: Electrochemical and Physicochemical
Properties, John Wiley, New York, 1988.
[8] C.A. Bessel, K. Laubernds, N.M. Rodriguez, R.T.K. Baker, J.
Phys. Chem. B 105 (6) (2001) 1115.
[9] E.S. Steigerwalt, G.A. Deluga, D.E. Cliffel, C.M. Lukehart, J.
Phys. Chem. B 105 (34) (2001) 8097.
[10] B. Rajesh, V. Karthik, S. Karthikeyan, K.R. Thampi, J.M.
Bonard, B. Viswanathan, Fuel 81 (2002) 2177.
[11] Z.L. Liu, X.H. Lin, J.Y. Lee, W.D. Zhang, M. Han, L.M. Gan,
Langmuir 18 (2002) 4054.
[12] W.Z. Li, C.H. Liang, W.J. Zhou, J.S. Qiu, Z.H. Zhou, G.Q. Sun,
J. Phys. Chem. B 107 (2003) 6292.
[13] T. Matsumoto, T. Komatsu, H. Nakano, K. Arai, Y. Nagashima,
E. Yoo, T. Yamazaki, M. Kijima, H. Shimizu, Y. Takasawa, J.
Nakamura, Catal. Today 90 (2004) 277.
[14] C. Kim, Y.J. Kim, Y.A. Kim, T. Yanagisawa, K.C. Park, M.
Endo, M.S. Dresselhaus, J. Appl. Phys. 96 (2004) 5903.
[15] Yangchuan Xing, J. Phys. Chem. B 108 (50) (2004) 19255.
[16] C. Wang, M. Waje, X. Wang, J.M. Tang, C.R. Haddon, Y. Yan,
Nano Lett. 4 (2) (2004) 345.
[17] M. Carmo, V.A. Paganin, J.M. Rosolen, E.R. Gonzalez, J. Power
Sources 142 (2005) 169.
[18] T. Yoshitake, Y. Shimakawa, S. Kuroshima, H. Kimura, T.
Ichihashi, Y. Kubo, D. Kasuya, K. Takahashi, F. Kokai, M.
Yudasaka, S. Iijima, Physica B 323 (2002) 124.
[19] T. Hyeon, S. Han, Y.E. Sung, K.W. Park, Y.W. Kim, Angew.
Chem. Int. Ed. 42 (2003) 4352.
[20] K.W. Park, Y.E. Sung, S. Han, Y. Yun, T. Hyeon, J. Phys. Chem.
B 108 (2004) 939.
[21] G.S. Chai, S.B. Yoon, J.S. Yu, J.H. Choi, Y.E. Sung, J. Phys.
Chem. B 108 (2004) 7074.
[22] S.H. Joo, S.J. Choi, I. Oh, J. Kwak, Z. Liu, O. Terasaki, R. Ryoo,
Nature 412 (2001) 169.
[23] M. Uchida, Y. Aoyama, M. Tanabe, N. Yanagihara, N. Eda, A.
Ohta, J. Electrochem. Soc. 142 (1995) 2572.
[24] S.C. Roy, P.A. Christensen, A. Hamnett, K.M. Thomas, V.
Trapp, J. Electrochem. Soc. 143 (1996) 3073.
[25] A.K. Shukla, M.K. Ravikumar, A. Roy, S.R. Barman,
D.D. Sarma, A.S. Arico, J. Electrochem. Soc. 141 (1994)
1517.
[26] S. Ye, A.K. Vijh, L.H. Dao, J. Electrochem. Soc. 144 (1997)
90.
[27] T. Maiyalagan, B. Viswanathan, Mater. Chem. Phys. 93 (2005)
291.
[28] M. Steinhart, J.H. Wendorff, A. Greiner, R.B. Wehrspohn,
K. Nielsch, J. Schilling, J. Choi, U. Goesele, Science 296 (2002)
1997.
[29] S.C. Tsang, P. de Oliveira, J.J. Davis, M.L.H. Green, H.A.O. Hill,
Chem. Phys. Lett. 249 (1996) 413.
[30] K. Kinoshita, J. Electrochem. Soc. 137 (1990) 845.
[31] E. Antolini, L. Giorgi, F. Cardellini, E. Passalacqua, J. Solid State
Electrochem. 5 (2001) 131.
[32] S.C. Hall, V. Subramanian, G. Teeter, B. Rambabu, Solid State
Ionics 175 (2004) 809.
[33] P.L. Antonucci, V. Alderucci, N. Giordano, D.L. Cocke, H. Kim,
J. Appl. Electrochem. 24 (1994) 58.
[34] M.C. Roman-Martinez, D. Cazorla-Amoros, A. LinaresSolano, C. Salinas-Martinez de Lecea, Curr. Top. Catal. 1
(1997) 17.
[35] M.C. Roman-Martinez, D. Cazorla-Amoros, A. Linares-Solano,
C. Salinas-Martinez de Lecea, H. Yamashita, M. Anpo, Carbon
33 (1) (1995) 3.
[36] C.G. Vayenas, S. Bebelis, C. Pliangos, S. Brosda, D. Tsiplakides,
Electrochemical Activation of Catalysis, Promotion, Electrochemical
8. 912
T. Maiyalagan et al. / Electrochemistry Communications 7 (2005) 905–912
Promotion, and Metal–support Interactions, Kluwer, New York,
2001.
[37] K.E. Swider, D.R. Rolison, J. Electrochem. Soc. 143 (3) (1996)
813.
[38] K. Jiang, A. Eitan, L.S. Schadler, P.M. Ajayan, R.W. Siegel, N.
Grobert, M. Mayne, M. Reyes-Reyes, H. Terrones, M. Terrones,
Nano Lett. 3 (3) (2003) 275.
[39] T. Maiyalagan, B. Viswanathan, U. Varadaraju, in preparation.