Transcript Novel Nano-rods PtSn electro

Novel Nano-Rods PtSn electrocatalysts for fuel cells
Alex Schechter
Ariel University Center
July 2011
Fuel cells & electrochemistry
Group Activities at AUC
• Non- Pt selective catalysts for DMFC and PEMFC , with high
selectivity towards oxygen reduction in high concentrations of
methanol
• Active and durable catalysts and catalyst support materials
based on Sn and PtSn
• Novel design of fuel cell prototypes
• Hydrogen generation materials and devices from primary
hydrides for PEMFC
Direct methaol fuel cell(DMFC) Concept
Anode
6e-
6e-
Methanol
solution In
Cathode
In Air
– O2
Membrane/
Separator/
Electrolyte
CO2 Out
Water +
Methanol
Residue
6H+
3H2O
Challenges in Fuel cell catalysis
 Activity
 Price & Availability
 Durability over time
Pt instability in fuel cells
P. J. Ferreira, and Y. Shao-Horn. Electrochem. Solid State Lett. 10, B60 (2007).
Tin (Sn) Nanorods in Core shell as catalyst material for
fuel cell
Metallic Sn
core
SnO2 shell
Impregnation with
NaBH4 as a
reduction agent
Microwave irradiation
Electrodeposition method
Ultrasound irradiation
Atomic layer deposition
Catalyst on Sn NR
Sn NR
Sn/SnO2 nano roads prepared at
AUC fuel cells lab
Tin Melting in a Core-shell NR structure
Sn m.p.
PtSn
Pt
1.50E-01
1.00E-01
50th cycle
Current, mA
5.00E-02
0.00E+00
-0.2
-5.00E-02
1st cycle
0
0.2
0.4
-1.00E-01
-1.50E-01
-2.00E-01
-2.50E-01
-3.00E-01
-3.50E-01
Voltage, V
0.6
0.8
1
0.8
0.7
0.6
E, mV
0.5
0.4
Microwave synthesized PtSn
0.3
0.2
0.1 Commercial
PtRu
0
0
50
100
150
200
250
300
I, mA/mg Pt in anode
350
400
450
 NR 50nm x 300nm provide very high surface area.
Stable support for Pt in acid environment.
Low resistivity due to a core shell structure.
Formation of conductive 3D network structure is made plausible by low T
sintering of NR.
 Highly active PtSn alloy and Pt on SnO2 support show excellent activity towrdes
most widely used fuels in fuel cells.
Use of advance methods (Electrochemical ALD) and can increase the catalysts
utilization and reduce the fuel cell cost.
Partnership Sought
Collaborator 1
Fuel cell material developing group or company seeking
alternatives catalysts to the state of the art Pt or PtRu on
carbon support
Collaborator 2
• Dynamic fluidic calculation of 3D-NR structure
• Mathematical model mass and electrical balance of the fuel
cell
Collaborator 3
• Theoretical quantum mechanical study of methanol&
hydrogen oxidation on Pt and PtSnO2
acknowledgements
• Dr. Hanan Teller
• Dr. Olga Krachevsky
Thank You
e-