catalysts for sustainable fuel cell electric vehicles€¦ · catalysts for sustainable fuel cell...
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Catalysts for Sustainable Fuel Cell Electric
Vehicles
Anusorn Kongkanand, Wenbin Gu, and Mark F. Mathias
General Motors,
Fuel Cell Business
IEA-TCP Advanced Fuel Cells, Berlin
November 15, 2017
Thanks to Kurt Wellenkotter, Venkata Yarlagadda, Mike Carpenter, Yun Cai,
Thomas E. Moylan, Wenbin Gu, Sonam Patel, Kathryn Stevick, Peter Harvey, Cristin Keary, Shruti Gondikar,
Ratandeep Kukreja, Roland Koestner, David Masten, Swami Kumaraguru
Partial Funding by the US DOE-EERE under grant DE-EE0007271
2
Electrification Technology Application Map
Light Load
ContinuousStop-and-go
High Load
City HighwayIntra-urban Highway-cycle
Drive Cycle
Du
ty C
ycle
Fuel Cell
E-REV
BEV
• Li-ion batteries and fuel cells (and combinations) have roles to play.
• The boundaries of these application spaces will be determined by economics.
2014
Cars with 120,000 milesFleet >3 M miles
GM’s Hydrogen Fuel Cell Milestones1964 to 2020+
Demonstrated progress achieving critical metrics, on path toward commercialization
Dynamic Load Following
Freeze
Power Density
300 mile Range
Fast (3 min.) Refueling
Durability
Cost Roadmap
✓
✓
✓
✓
✓
✓
✓
Investment - ManufacturingGM & Honda Announce Joint Manufacturing Venture
Gen 2 Fuel Cell System
Joint Fuel Cell Manufacturing Facility
• 50:50 Manufacturing Joint Venture (GM & Honda)• Announced January 30, 2017• Manufacturing Location: Brownstown Township, MI
• $85 Million initial investment, creating over 100 new jobs
• Fuel cell production expected around 2020• Extensive automation
• Product based upon shared Gen 2 development program
• Substantial cost reduction through design iterations & scale economies
• Technology becoming affordable for automotive applications
Emerging industrial/military applications looking to fuel cell
FUEL CELL PERFORMANCE FACTORS
STEALTH✓
HEAVY VEHICLE✓
LONG RANGE✓
FAST REFUELING✓
COLD & HOT AMBIENTS✓
• Early applications where fuel cell solves problems• Attractive in centrally fueled fleets with high vehicle usage
Extended Mission (Duration & Range – Months NOT Days)Increased Maneuvering PowerReduced Risk of Detection
• Low Acoustic & Thermal Signatures• No Smoke – Odorless (Water is Only Exhaust)
Reduced Recharging/Refueling Time (Minutes NOT Hours)Expanded Range of Operating Conditions
• Hot & Cold Environments• Without Performance Compromises
Simplified Logistics for Service/RepairIncreased Use of Diverse Energy Resources
• Undersea Hydrogen Generation & Fueling
Added Scalability• Range of Vehicle Architectures & Applications
Unmanned Undersea Fuel Cell OpportunitiesWhat can Hydrogen Fuel Cell Technology Offer?
http://media.gm.com/media/us/en/gm/news.detail.html/content/Pages/news/us/en/2016/oct/1003-zh2.html
• GM/ Army TARDEC (Tank Automotive Research, Development & Engineering Center
• Compared to HUMVEE• > off-road capability• Lower heat signature• Silent to 100 vs. 1,000 meters
• Full torque at launch• Exportable power for command or
medical facility• Produces 2 gallons of water per hour
Chevy Colorado ZH2 – Forbes, CNN, Maxim, Car & Driver, Defense News
Let’s Make Something Happen
Fuel Cell-Powered FlexibleTechnology Integration
SilentUtlityRoverUniversalSuperstructure
From Satyapal, DOE Annual Merit Review 2017
Affordable consumer vehicles are needed to grow H2 economy to the scale that drives cost down.
State-Of-The-Art Fuel Cell Vehicle
~35 gPt/vehicle
Significant reduction of Pt. But still much higher than ICE vehicles (<5 gPt/vehicle).
Requires very large radiator to reject waste heat (2x of ICE).
Cost is decreasing but very sensitive to volume.
From DOE AMR 2017, James et al. fc163
12
Mirai PtCo, 0.33 mgPt/cm2
Pt, 0.40 mgPt/cm2
H2/air, 94°C, 250/250 kPaabs,out, 65/65% RHin, st=1.5/2
DOE Target 0.44 A/mgPt
Performance of Proven Catalysts
Mirai PtCo cathode catalyst ORR mass activity is ~1.8x of Pt/C.
Shows slightly better fuel cell performance than older Pt/C electrode despite smaller Pt
loading.
Fuel Cell Propulsion System Cost Glide Path
• Now that we can build a durable and efficient fuel cell, our focus has been toward FCPS cost reduction and precious metal reduction.
14
Stack Cost and Pt Amount
As Pt loading decreases, fuel cell efficiency decreases.
Stack cost only declines until Pt loading is about 0.1 mgPt/cm2 (~10 gPt/vehicle), at which point the stack active area must rise to maintain sufficient efficiency.
Lower Pt amount does not always mean lower cost.
J. Phys. Chem. Lett. (2016) 1127.
10 g 30 g3 gPt per vehicle
15Roland Berger study, 2013
J. Phys. Chem. Lett. (2016) 1127.
❖ How much Pt in a wedding ring ?
Long-term Pt target is not about cost
Even at 10 g-Pt/veh, Pt demand/supply will shift, putting pressure on Pt price.
Need to cut Pt usage to the replacement level of IC engines (2-8 g-Pt/veh).
Is jewelry the optimal use of Pt ?
16
> 95% jewelry
80-90% industrial
50-55% automotive
5-10% electronics
Precious metal recycling >97% is technically feasible
and profitable.
Collecting components back from customers to the
refiners is the key in its life cycle.
Need change in public perspective from “waste
management” to “resource management”.
Likely need support from policy makers at many
levels.
Pt Life-Cycle
From Hagelüken, Platin. Met. Rev. 2012, 29
PEM Fuel Cell
1-3 H2O (drag)
H+
backdiffusion
H2OH2
H2O H2O
O2
2H2 4H+ + 4e‒ O2 + 4H+ + 4e‒ 2H2O
Anode CathodeMembraneDMBP BPDM
200 μm 200 μm10 μm 10 μm20 μm
e‒ e‒
Electrical Load
Normal operation
Full power Most performance loss occurs in the
cathode.
Under normal operation (low power),
mostly cathode kinetic loss
At higher power, electrode reaction
kinetics and O2/proton/water/heat
transports fully coupled.
18
a)
b) c)
H+
H2O
H2O
O2
O2 + 4H+ + 4e‒ 2H2O
CathodeMembrane BPDM
--
---
--
carbon
Pt
ionomer
O2
Large performance loss at high-current density is observed on low-Pt cathodes due to higher flux of
O2 per a given Pt area.
The ‘local O2 transport resistance’ dominates the mass transport related loss (purple) at HCD on low-
Pt electrode. Must be addressed.
Mass-transport voltage
losses at 1.75 A/cm2 on a
0.10 mgPt/cm2 cathode
0.4
0.5
0.6
0.7
0.8
0.9
0 0.5 1 1.5 2
Vo
lta
ge (
V)
Current Density (A/cm²)
PtCo, 0.20
PtCo, 0.10
PtCo, 0.05
Lo
we
r P
t lo
ad
ing
Cathode
mgPt/cm2
H2/air, 94°C, 250/250 kPaabs,out, 65/65% RHin, st=1.5/2
O2
O2
J. Phys. Chem. Lett. (2016) 1127.
Challenge for Low-Pt Cathode: Local O2 Transport Resistance
19
Local Transport is Universal for all Dispersed Catalyst
𝑳𝒐𝒔𝒔 𝒇𝒓𝒐𝒎 𝒍𝒐𝒄𝒂𝒍 𝒓𝒆𝒔𝒊𝒔𝒕𝒂𝒏𝒄𝒆
∝𝑹𝑶𝟐,𝑷𝒕−𝒍𝒐𝒄𝒂𝒍
𝑬𝑪𝑺𝑨 ∙ 𝑷𝒕 𝒍𝒐𝒂𝒅𝒊𝒏𝒈
0.3
0.4
0.5
0.6
0.7
0 25 50 75 100 125
Vo
ltag
e a
t 1
.75
A/c
m2
MEA
(V)
r.f. (cm2-Pt/cm2
MEA)
Pt/CPtCo/CPtCo/C + new PFSA
NSTF
NSTF + 2nm PFSA
2 n
m io
no
mer
Improved ionomer-PtPtCo
PtNSTF
O2
O2
The ‘local O2 transport resistance’ rises inversely proportional to the available Pt area.
Voltage at high-current density drops precipitously below a roughness factor of ~50 (~0.1 mgPt/cm2 or
10 gPt/vehicle).
J. Phys. Chem. Lett. (2016) 1127.
20
For a well optimized electrode, one can predict the approximate performance at both low and high
current density from just two parameters : ORR activity and Pt surface area.
A catalyst must have a combination of oxygen reduction mass activity and Pt surface area that is
higher than these lines.
Catalysts with low surface area cannot meet the requirement.
Impact of Local Resistance on High-Power Performance
J. Phys. Chem. Lett. (2016) 1127.
0
0.2
0.4
0.6
0.8
1
0 50 100 150
Mas
s A
ctiv
ity
(A/m
g Pt-
eq
v)
Pt Surface Area (m2/gPt-eqv)
0.62
0.60
0.58
0.48
0.56
0.54
Voltage at 2 A/cm2
Cathode Pt loading 0.10 mgPt/cm2
O2O2
𝑳𝒐𝒔𝒔 𝒇𝒓𝒐𝒎 𝒍𝒐𝒄𝒂𝒍 𝒓𝒆𝒔𝒊𝒔𝒕𝒂𝒏𝒄𝒆
∝𝑹𝑶𝟐,𝑷𝒕−𝒍𝒐𝒄𝒂𝒍
𝑬𝑪𝑺𝑨 ∙ 𝑷𝒕 𝒍𝒐𝒂𝒅𝒊𝒏𝒈RO2,local of 12 s/cm
21
0
0.2
0.4
0.6
0.8
1
0 50 100 150
Mas
s A
ctiv
ity
(A/m
g Pt-
eq
v)
Pt Surface Area (m2/gPt-eqv)
0.05mg/cm2, 2.0A/cm2
0.10mg/cm2, 2.0A/cm2
0.10mg/cm2, 1.5A/cm2
NSTFMonolayer
Alloy/Dealloyed
DealloyedPtCo and
PtNi
NSTFPt3Ni7
Pt-ML/Pd
Pt-ML/PdWNi
OctahedralPtNi
Pt
0.10 mgPt/cm2, 2 A/cm2
0.10 mgPt/cm2, 1.5 A/cm2
In theory, current Pt-alloy catalyst is capable for giving 2 A/cm2 at 10 gPt system.
However, higher Pt surface area and ORR activity are needed for meeting requirement at
5 gPt system (unless we can further reduce the local resistance)
Higher ECSA and ORR activity remain highest priority.
Catalyst Roadmap for High-Power Performance
J. Phys. Chem. Lett. (2016) 1127.
~10 g of Pt per vehicle
~5 g of Pt per vehicle
RPt of 12 s/cm and 0.58 V requirement
22
A. Increase Pt surface area
B. Reduce Pt-local O2 transport resistance
C. Increase ORR activity
0
0.2
0.4
0.6
0.8
1
0 50 100 150
Mas
s A
ctiv
ity
(A/m
g Pt-
eq
v)
Pt Surface Area (m2/gPt-eqv)
0.05mg/cm2, 2.0A/cm2
0.10mg/cm2, 2.0A/cm2
0.10mg/cm2, 1.5A/cm2
NSTFMonolayer
Alloy/Dealloyed
DealloyedPtCo and
PtNi
NSTFPt3Ni7
Pt-ML/Pd
Pt-ML/PdWNi
OctahedralPtNi
Pt
0.10 mgPt/cm2, 2 A/cm2
0.10 mgPt/cm2, 1.5 A/cm2
𝐋𝐨𝐬𝐬 𝐟𝐫𝐨𝐦 𝐥𝐨𝐜𝐚𝐥 𝐫𝐞𝐬𝐢𝐬𝐭𝐚𝐧𝐜𝐞
∝𝐑𝐎𝟐,𝐏𝐭−𝐥𝐨𝐜𝐚𝐥
𝐄𝐂𝐒𝐀 ∙ 𝐏𝐭 𝐥𝐨𝐚𝐝𝐢𝐧𝐠
Approaches to Improve High-Power Performance
23
0.4
0.5
0.6
0.7
0.8
0.9
0 1 2
Vo
ltag
e (
V)
Current (A/cm2)
Pt
ACS Catalysis. (2016) 1578.
Still too much PGM in the core (Pd costs the same as Pt per weight, one-half per atom).
Not currently economically competitive.
Not sufficiently stable. Need improvement in core stability.
High Surface Area Catalyst Can Meet High-Power Performance
Pt: 0.05 mg/cm2
A. Increase Pt surface area
H2/air, 80°C, 150 kPaabs,out, 100% RH, high stoich
24
If we reduce the resistance by half, the requirement line will move left halfway
to the Y-axis, enabling many more catalysts.
But ‘How can we reduce local O2 resistance?’
➢ Need to know what causes it, and know how to evaluate it.
J. Phys. Chem. Lett. (2016) 1127.
0
0.2
0.4
0.6
0.8
1
0 50 100 150
Mas
s A
ctiv
ity
(A/m
g Pt-
eq
v)
Pt Surface Area (m2/gPt-eqv)
0.10 mgPt/cm2, 2 A/cm2
Reducing local O2 resistance
6 s/cm
6 s/cm
12 s/cm
12 s/cm
B. Reduce Pt-local O2 transport resistance
Implication of Lower Local O2 Resistance
25
Ionomer-Pt Interface is the Key
MD-DFT simulation showed formation of a
dense layer of ionomer adjacent to the Pt
surface reducing O2 concentration leading to
large O2 resistance.
Jinnouchi et al. EC Acta, 2016, 188, 767
MD/DFT of ionomer-Pt interface
0.3
0.4
0.5
0.6
0.7
0 25 50 75 100 125
Vo
ltag
e a
t 1
.75
A/c
m2
MEA
(V)
r.f. (cm2-Pt/cm2
MEA)
Pt/CPtCo/CPtCo/C + new PFSA
NSTFNSTF + 2nm PFSA
2 n
m io
no
mer
Improved ionomer-PtPtCo
PtNSTF
O2
O2
JPC Lett. 2016, 7, 1127
Loss is not observed if ionomer is absent on
Pt surface.
26
Orfanidi et al. JES, 2017, 164, F418
0.3
0.4
0.5
0.6
0.7
0 25 50 75 100 125
Vo
ltag
e a
t 1
.75
A/c
m2
MEA
(V)
r.f. (cm2-Pt/cm2
MEA)
Pt/CPtCo/CPtCo/C + new PFSA
NSTF
NSTF + 2nm PFSA
2 n
m io
no
mer
Improved ionomer-PtPtCo
PtNSTF
Ionomer-Pt Interface is the Key
--
---
--
carbon
Pt
ionomer
a)
O2
--
--
Pt
b)
carbon
O2
Performance and stability can be improved with
alternative ionomer structures.JPC Lett. 2016, 7, 1127
Jomori et al. JES, 2013, 160, F1067
Altering carbon surface and hence ionomer
distribution may also do it.
CarbonOuter PtInner Pt
50wt%Pt / Vulcan10wt%Pt / Vulcan50wt%Pt / HSC10wt%Pt / HSC
Carbons: Catalysts can look very differentPadgett, Muller et al.
28
✓High Pt dispersion
✓High ORR activity
✓Easy to make good alloy
✓Good O2/proton transport
✓Better stability
Solid carbon
MSC (Vulcan)
Porous carbon
HSC
Carbon Supports
Porous carbon
Solid carbon
Good kinetic
Poor transport
Good transport
Poor kinetic
The type of carbon support affects not only the transport properties of the
catalyst layer but also the kinetic activity of the catalysts.
More Pt particles in porous carbon are shielded from ionomer adsorption➢ boost activity and transport ?
Porous carbon can show up to 3-4 times higher activity, resulting in higher
performance in most operating conditions.
--
---
--
carbon
Pt
ionomer
O2
Mass-transport Voltage Losses
H+, O2
1.75 A/cm2 on a 0.10
mgPt/cm2 cathode
O2 through Ionomer/Pt Interface H+ and O2 through Carbon
Micropores
Transports in Porous Carbons
Pt particles in porous carbon are not as accessible to proton and O2 and can cause
additional transport loss.
Ideally, want pores to keep ionomer away but not too far so that proton cannot get to Pt,
and the pore should not restrict O2 transport.
Questions: How accessible are the Pt to proton and O2?
What’s the proton transport mechanism in ionomer-free pores?
What is the geometry/distribution of the pores?
Carbons: Performance Characteristics
31
Carbons: Trade-off Between ORR and Transports
Proton and Local O2 transport generally correlate.
But ORR activity can break the trend.
Some porous carbon can show good activity with reasonable transport resistances.
mesopore engineering
0.0
0.1
0.2
0.3
0.4
0
5
10
15
20
0% 20% 40% 60% 80% 100%
OR
R A
ctiv
ity
(A/m
g Pt)
Loca
l O2
Re
sist
ance
(s/
cm)
Dry Pt Utilization
Solid carbons
Porous carbons
Pt/HSC-e
Proton Accessibility
32
0.55
0.65
0.75
0.85
0 0.5 1 1.5 2
Vo
lta
ge
(V
)
Current Density (A/cm²)
H2/air, 250 kPa, 94°C, 65%RHin, stoich 1.5/2
Mirai PtCo, 0.33 mgPt/cm2
New PtCo, 0.10 mgPt/cm2
Pt, 0.40 mgPt/cm2
Old PtCo, 0.10 mgPt/cm2
PtCo Catalyst with Optimized Transport
Optimization of PtCo particles and carbon
support structure provide a path to meet
both activity and high power performance
target for 0.1 mg/cm2 Pt loading.
10 gPt/vehicle is close to reality.
DOE Target 0.44 A/mgPt
0.1 mgPt/cm2, 2 A/cm2
0.1 mgPt/cm2, 3 A/cm2
0.05 mgPt/cm2, 2 A/cm2
RPt of 10 s/cm
• ORR activity (41 mV)
• Local transport (18 mV)
• Local transport (67 mV)
• ORR activity (53 mV)
• Ohmic losses (39 mV)
• Bulk O2 transport (21 mV)
• Electrode proton (20 mV)
Additional losses
Additional losses
Less Pt per area
Smaller stack
Total loss 0.71 V
Total loss 0.56 VTotal loss 0.50 V
Paths to Lower Pt
Further reduction of Pt (5 gPt/vehicle) requires
higher ORR activity catalyst and electrode with
lower local transport resistance.
34
PtM3/C -------------> Pt1.5-5M/Cprecursor dealloying catalyst
e.g., acid leaching,
electrochemically dissol’n
Cross
section, Pt
in blue
Lattice compression of surface Pt layer
Jia et al. ACS Catal., 2016, 6, 928. Oezaslan et al. JACS., 2012, 134, 514.
Currently the most mature high-activity catalyst
Many factors can affect resulting structure, performance, and stability.
Larger precursor Porous
Smaller precursor Solid core-shell
The Current Best: Dealloyed Catalysts
Energy Environ. Sci., 2014.
Exceptional Durability of ORR Activity with DealloyedPtNi/HSC and PtCo/HSC
0
100
200
300
400
500
600
0 500 1000 1500 2000
Mas
s Act
ivity
(A/g
Pt)
Run time (hr)
JM PtCo, 0.10mg/cm2 MA(A/gPt)
JM PtNi, 0.10mg/cm2 MA(A/gPt)
Stack
DOE Final Report, 2014. https://www.osti.gov/scitech/biblio/1262711
• Meeting DOE ORR durability in MEA. Validated at multiple sites.
• Durable ORR kinetics in stack testing.
• Need thicker Pt shell for MEA stability (>4ML). Optimization point for is very different from RDE (~1ML).
36
Specific activity correlates with OOH surface species in lieu of OH dominating. This points to a relatively lower Pt-O bond strength.
Jia et al. ACS Catal., 2016, 6, 928; JECS 2014, 161, F1323.
Caldwell et al. JPC C, 2015, 119, 757.
Dealloyed catalysts do degrade over time.
But can maintain high activity even with substantial Ni loss.
Dealloyed catalysts decay but can maintain activity
Fuel cell operation
Up to 70x Pt activity enhancement has been demonstrated ex-situ in RDE measurements.
(11x better than the current best dealloyed PtCo/PtNi catalysts).
Can we make it work in the real world?
Strasser, Science 2015
C. Increase ORR activity
Shape-Controlled Catalysts
38
Need better understanding to determine if
these losses can be mitigated.
Loss of shape and activity in fuel cell
J. Phys. Chem. Lett. (2016) 1127.Strasser and coworkers, Nat. Mater. 2013
Current shape-controlled PtNi catalysts generally lost Ni more quickly, leading to
poor stability.
Ni-rich facets provide a weak spot for dissolution.
May need thicker Pt shell, (from 1-2 4-7 layers of Pt). But would it still give
high activity?
39
From Discovery to Realization in a Fuel Cell
o Dashed line series are the RDE and solid line series are the MEA results.
o All are the initial activity.o Filled symbols represent works that
are funded by DOE.
For concepts that worked out (dealloyed and Pt-monolayer catalysts), it took
>8 years to get from RDE to real-life MEA.
Not all emerging catalysts will work. But among those that work, they often
look different from when were first discovered in RDE.➢ Requires iterative developments in MEAs
40
False positive
(Waste time&money)
False negative
(Missed opportunity)
What else had we missed ?
For most advanced catalysts, there are little agreement between RDE and MEA.
RDE test is a poor predictor of both activity and stability.
Catalyst development should be shifted to MEA as early as possible.
Ea of 10 kJ/mol (MEA)
Ea of 25 kJ/mol (RDE)
Yarlagadda et al. (2017) JES.
Activity Measurements
41
MEA Preparation from mg of Catalyst
a) b)
GDL
ultrasonicnozzle
funnel
vacuum
sand core filter
collecting bottle
GDL
Developed two procedures to coat fuel cell
electrodes from 30 mg of catalyst powder (same
amount as an RDE ink).
Observed reasonable coating quality and fuel cell
performance.
Worked with Ketjen and Vulcan blacks.
Expedite learning cycles. No scale-up required.
Yarlagadda et al. (2017) JES.
0
10
20
30
40
50
60
0 10k 30k
EC
SA
(m
2/g
Pt)
SOA USC VF
0
0.1
0.2
0.3
0.4
0.5
0 10k 30k
Mass A
cti
vit
y (
A/m
gP
t) SOA USC VF
a)
b)
c)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.0 0.2 0.4 0.6 0.8
Vo
lta
ge
(V
)
Current Density (A/cm²)
Thin GDL, SOA
Thin GDL, VF
Thick GDL, SOA
Thick GDL, USC
0.2
0.4
0.6
0.8
1
0.0 0.5 1.0 1.5 2.0
V
i
Number of voltage cycles
Number of voltage cycles
42
funnel
clampGDL
porous
glass
filter
Vacuum pumpCollecting bottle
Top View
GDLclamp
funnelRDE ink
Before After Filtration
Vacuum Filtration Apparatus
Typical ink
• 30 mg PtX/C
• 37 g water
• 3 g isopropanol
• D2020 ionomer (I/C of 1)
d) c)
b) a)
30 μm
MPL
Catalyst layer
Sample spacer
0.1 1 10 100
Fre
qu
en
cy
Particle Diameter (μm)
Vacuum Filtration
SEM: Top View
SEM: Cross-section
New recipe, Pt/V
43
25 s/cm RO2,local, 6x ORR
10 s/cm RO2,local, 6x ORR
10 s/cm RO2,local, 12x ORR
10 s/cm RO2,local, 70x ORR
23% up
54% up
Substantial improvement at high power and stack cost reduction can be realized with
higher activity.
~23% improvement with additional 2x, ~54% with additional 11x over the current best
catalyst.
5% increase in fuel efficiency.
And most importantly, enabling 5 gPt/vehicle.
Pt: 0.05 mg/cm2
Strasser, Science 2015
How far can we go ?
44
Summary
Proven technology with 35 g of Pt per vehicle is now on the road. Next-
generation FCEVs are expected to use 10-20 g of precious metal.
Considering commercial factors, a long-term target should be comparable to
that used in automotive catalytic convertors (~5 g of precious metal).
Further reduction of Pt demands a catalyst with higher ORR activity.
Developing emerging catalysts requires proper evaluation.
Fundamental understanding of the origin of the local transport resistance is
needed in order to optimally engineer the nanostructure near the catalyst
active surfaces.
AcknowledgementsDOE
– Greg Kleen (Program Manager)
– Bahman Habibzadeh (Technology Manager)
– Shaun Onorato
General Motors
– Aida Rodrigues, Yevita Brown, Charles Gough
(Contract Managers)
– Venkata Yarlagadda
– Michael K. Carpenter
– Yun Cai
– Thomas E. Moylan
– Joseph M. Ziegelbauer
– Ratandeep Singh Kukreja
– Taylor Garrick (Univ South Carolina)
– Wenbin Gu
– Srikanth Arisetty
– Roland Koestner
– Cristin L. Keary
– Qiang Li and team
– Peter Harvey and team
– Sonam Patel, Kathryn Stevick and team
– Tim Fuller
– Shruti Gondikar
– Mohammed Atwan
– Nagappan Ramaswamy
– Dave Masten
– Swami Kumaraguru
– Craig Gittleman
– Mark F. Mathias
3M
– Dr. Andrew Haug (sub-PI)
– Matthew Lindell
– Tyler Matthews
Carnegie Mellon University
– Prof. Shawn Litster (sub-PI)
– Shohei Ogawa
– Jonathan Braaten
Cornell University
– Prof. David A. Muller (sub-PI)
– Prof. Héctor Abruña
– Elliot Padgett
– Barnaby Levin
– Yin Xiong
– Yao Yang
Drexel University
– Prof. Joshua Snyder (sub-PI)
– Yawei Li
NREL
– Dr. K.C. Neyerlin (sub-PI)
– Jason Christ
– Shaun Alia
– Jason Zack
– Shyam Kocha
– Bryan Pivovar
ANL / APS
– Dr. Deborah J. Myers
– Dr. Nancy N. Kariuki
– Dr. Ross N. Andrews (beamline 9ID)