A polyol reduction method is employed to prepare carbon-supported Pt and Pt-M (M ) Fe, Co, and Cr) alloy catalysts by simultaneous reduction and decomposition of metal precursors with 1,2-hexadecanediol in the presence of nonanoic acid and nonylamine protecting agents. The prepared materials are characterized by powder XRD, HRTEM, and EDX. The face-centered cubic structure of Pt in the prepared materials is evident from XRD. Good dispersion of Pt and Pt alloy nanoparticles on the carbon support is seen from the highresolution TEM images. The presence of respective elements with controlled composition is observed from EDX analysis. Electrochemical performance of the prepared materials is investigated by cyclic voltammetry and tested in a single-cell DEFC. The inhibition of formation of (hydr)oxy species on the Pt surface by the presence of alloying elements is observed. Oxygen reduction activity of the Pt-M/C (M ) Fe, Co, and Cr) is found to be ̃1.5 times higher than that of the as-synthesized and commercial Pt/C catalysts. Single-cell DEFC tests indicated the good performance of Pt-M/C (M ) Fe, Co, and Cr) compared with that of the as-synthesized and commercial Pt/C catalysts. The DEFC performance increased in the order Pt/Ccomm < Pt/Cas-syn < Pt-Fe/C < Pt-Co/C ̃ Pt-Cr/C. Stability under DEFC operating conditions for 50 h indicated the good stability of Pt alloys compared with that of Pt catalysts. © 2009 American Chemical Society.

Ch Venkateswara Rao

Balasubramanian Viswanathan

ALLOY CATALYST

CARBON SUPPORT

EDX analysis

Electrochemical performance

FACE-CENTERED CUBIC STRUCTURE

GOOD STABILITY

HIGH-RESOLUTION TEM

Metal precursor

NONANOIC ACID

Operating condition

Oxygen Reduction

Powder XRD

PROTECTING AGENT

PT ALLOY

Pt catalysts

Reduction method

Simultaneous reduction

SUPPORTED PT

Alloying elements

Alloys

catalysis

CATALYSTS

Chromium

Cyclic voltammetry

DIRECT ETHANOL FUEL CELLS (DEFC)

Electrolytic reduction

Ethanol

ETHANOL FUELS

Iron alloys

Oxygen

Platinum

X ray diffraction

X ray diffraction analysis

Platinum alloys

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Physical Chemistry C

We report a significant increase in the performance of a hybrid carbon structure of one dimensional (1D) multi-walled carbon nanotubes (MWNTs) and 2D graphene sheets as the catalyst support material for proton exchange membrane fuel cells. A few upper layers of multiwalled carbon nanotubes were cut open in the longitudinal direction to achieve a hybrid structure of opened up MWNTs as graphene "wings" attached to the unaffected inner tubes by modifying the chemical oxidation method followed by hydrogen induced reduction technique. These partially exfoliated nanotubes (PENTs) were used as the support material for Pt deposition using chemical reduction with ethylene glycol. These PENTs supported Pt catalysts were used for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). An enhanced performance of 1000 mW/cm2 compared to a cell with a commercial Pt/C (418 mW/cm2) was achieved which was attributed to the specific structure of the support material giving an improved effectual surface area as well as higher conductivity. © 2015 Hydrogen Energy Publications, LLC.

International Journal of Hydrogen Energy

Platinum decorated on partially exfoliated multiwalled carbon nanotubes as high performance cathode catalyst for PEMFC

Graphite oxide (GO) was chemically altered using polyethylene glycol (PEG) to produce functionalized GO (f-GO). An ensemble of reduced f-GO sheets and multiwalled carbon nanotubes (MWNTs), referred to as few-layer graphene-MWNT sandwiches (GCSs), were synthesized by a catalysis-assisted chemical vapor deposition (CCVD) method and explored as the electrocatalyst support material for oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC). Platinum nanoparticles were decorated on the carbon supports by a modified glycol reduction technique. As-prepared electrocatalysts were characterized by Raman spectroscopy, X-ray diffraction and transmission electron microscopy. Electrocatalytic performance was evaluated by cyclic voltammetry and PEMFC fuel cell measurements and compared with a commercially available Pt/C electrocatalyst. The Pt/GCS electrocatalyst gave a maximum PEMFC performance of 495 mW cm-2 at 60°C temperature. The improvement in the ORR activity was ascribed to the uniform dispersion of Pt nanoparticles with an optimal particle size (∼3.5 nm) over a well-organized conducting catalyst support. © 2014 the Partner Organisations.

Fulltext

RSC Advances

Platinum-decorated chemically modified reduced graphene oxide-multiwalled carbon nanotube sandwich composite as cathode catalyst for a proton exchange membrane fuel cell

Carbon-supported Pd and Pd-Co-Au alloy electrocatalysts are prepared by water-in-oil microemulsion technique using water as aqueous phase, non-ionic Triton-X-100 as surfactant, and cyclohexane as oil phase. The materials are characterized using XRD, TEM, and EDX. Face-centered cubic structure of Pd and presence of respective elements with controllable composition is evident from the analysis of XRD and EDX. The role of alloying elements on the redox behavior as well as catalytic activity of Pd is studied by cyclic voltammetry and ultraviolet photoelectron spectroscopy. Electrochemical measurements performed by rotating disk electrode voltammetry indicate the good ORR activity of Pd-Co-Au/C compared to Pd/C. © 2011 Elsevier Inc.

Journal of Colloid and Interface Science

Microemulsion synthesis and electrocatalytic properties of carbon-supported Pd-Co-Au alloy nanoparticles

A series of Pt/C electrocatalysts with average Pt particle size of 1.8, 2.3, 3.4, 3.8, 4.7, and 5.8 nm are synthesized by reducing platinum(II) acetylacetonate with 1,2-hexadecanediol in the presence of long-chain carboxylic acid and alkylamine stabilizing agents. The prepared materials are characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray (EDX) spectrometry. The face-centered cubic structure of Pt in the materials is evident from XRD. Good spatial distribution of spherical shaped Pt nanoparticles is seen from the HRTEM images. The presence of Pt and C is observed from the EDX analysis. Linear sweep voltammetry (LSV), rotating disk electrode (RDE), and single-cell proton exchange membrane fuel cell (PEMFC) measurements are conducted to evaluate the electrocatalytic activity of Pt/C electrocatalysts. Electrochemical measurements indicate the good hydrogen oxidation and oxygen reduction activity for 1.8 and 3.4 nm size Pt particles, respectively. Kinetic analysis by RDE voltammetry reveals that the number of electrons transferred in hydrogen oxidation (HOR) and oxygen reduction (ORR) processes on 1.8 and 3.4 nm size Pt nanoparticles is 2 and 4, respectively. The high performance Pt/C anode and cathode are then used to fabricate a membrane-electrode assembly (MEA) and tested in a PEMFC. A maximum power density of 625, 760, and 1030 mW/cm2 is observed at 333, 343, and 353 K, respectively. © 2010 American Chemical Society.

Monodispersed platinum nanoparticle supported carbon electrodes for hydrogen oxidation and oxygen reduction in proton exchange membrane fuel cells

An unsupported Cu-Pt core-shell catalyst is prepared by a transmetalation reaction between copper and Pt2+ ions, and a Cu-Pt bimetallic alloy catalyst by a simultaneous reduction reaction. Both catalysts are subjected to electrochemical leaching without further treatment and their electrochemical characteristics and ORR activities are compared to that of a standard Pt black catalyst. Potential cycling in 0.1 M HClO4 and 0.5 M H 2SO4 shows that the core-shell catalyst is highly stable and the electrochemical features show that it is purely Pt on the catalyst surface. The electrochemical surface area of the Cu-Pt core-shell catalyst is much higher than that of the Pt black. When the Pt loading on the electrode is increased with Pt black catalyst to match its geometric electrochemical surface area (cm2/electrode area (cm2)) with that of Cu-Pt core-shell catalyst, the activity of the latter is still higher. The mass activities of Pt black, Cu-Pt binary alloy, and Cu-Pt core-shell catalysts measured using a rotating disk electrode are 0.053, 0.153 and 0.262 A mg -1Pt, and their respective specific activities are 197, 496, and 710 μA cm-2Pt. © 2012 The Electrochemical Society.

Journal of the Electrochemical Society

Unsupported Cu-Pt Core-Shell Nanoparticles: Oxygen Reduction Reaction (ORR) Catalyst with Better Activity and Reduced Precious Metal Content

The Journal of Physical Chemistry C

PtM/C Catalyst Prepared Using Reverse Micelle Method for Oxygen Reduction Reaction in PEM Fuel Cells

Design and Preparation of Highly Active Pt−Pd/C Catalyst for the Oxygen Reduction Reaction

Russian Journal of Electrochemistry

Nanostructured catalysts for cathodes of oxygen-hydrogen fuel cells

The Journal of Physical Chemistry B

Electrochemical Formation of a Pt/Zn Alloy and Its Use as a Catalyst for Oxygen Reduction Reaction in Fuel Cells

Journal of Applied Electrochemistry

Carbon supported Pt–Cr alloys as oxygen-reduction catalysts for direct methanol fuel cells

ORR activity and direct ethanol fuel cell performance of carbon-supported Pt-M (M ) Fe, Co, and Cr) alloys prepared by polyol reduction method

Journal	Journal of Physical Chemistry C
ISSN	19327447
Open Access	No