DOE Hydrogen Program.pdf

2021 DOE Hydrogen Program Annual Merit Review Slide 1
DOE Hydrogen Program
2021 Annual Merit Review and Peer Evaluation Meeting
June 7 – 11, 2021
ElectroCat 2.0
(Electrocatalysis Consortium)
Piotr Zelenay
Los Alamos National Laboratory
Deborah Myers
Argonne National Laboratory
Project ID: FC160
–
This presentation does not contain any proprietary, confidential, or otherwise restricted information

Overview
Timeline
• Start date: Oct 1, 2020
• End date: Sep 30, 2023
Budget
• FY21 funding total: $3M
• Planned FY22 funding: $3M
Barriers
• A. Cost (catalyst)
• D. Activity (catalyst; MEA)
• B. Durability (catalyst; MEA)
• C. Power density (MEA)
Laboratory – PI
Los Alamos National Laboratory
– Piotr Zelenay
Argonne National Laboratory
– Deborah Myers
National Renewable Energy Laboratory
– K. C. Neyerlin
Oak Ridge National Laboratory
– David Cullen
2021 DOE Hydrogen Program Annual Merit Review – Slide 2

Relevance and Goals
Heavy-Duty Transportation Fuel Cell Targets (2025) Electrolyzer Stack Goals (2025)
 Durability: 25,000 hour lifetime  Durability: 80,000 hour lifetime
 68% peak efficiency  70% efficiency at 3 A cm-2
 $80/kW fuel cell system cost  $100/kW
 Overall Target: 2.5 kW/gPGM power  Overall Target: $2/kg H2 over
(1.07 A cm-2 current density at 0.7 V after 25,000 hour- 80,000 hour lifetime
equivalent accelerated durability test)
End-of-consortium Goals:
Fuel Cell: H2-air performance of ≥ 100 mA/cm2 at 0.8 V and ≥ 500 mA/cm2 at 0.675 V at beginning of test (BOT) and
≥ 80 mA/cm2 and ≥ 400 mA/cm2 after 30,000 AST cycles (0.6 V to OCV, 3 s each, H2-air), respectively, under integral
conditions for a PEMFC with a PGM-free oxygen reduction catalyst
Electrolyzer: 2.5-fold increase, from 0.2 A/cm2 to 0.5 A/cm2 at 1.8 V and reduction in the voltage loss at a reference
current density of 0.2 A/cm2 from 0.2 mV/h to 0.1 mV/h with alkaline-exchange membrane electrolyzer using a PGM-
free oxygen evolution catalyst

Approach: FY20 and FY21 ElectroCat MiIestones
Date FY20 ElectroCat Annual Milestone GPRA Status
09/30/2020 Hydrogen-oxygen performance: Achieve PGM-free cathode MEA performance in an H2-O2 fuel cell of
32 mA cm-2 at 0.90 V (iR-corrected) at 1.0 bar partial pressure of O2 and cell temperature 80 °C.
Exceeded,
38 mA cm-2;
see slide #5
FY21 Milestone Name/Description End Date Type Status
Initiate ElectroCat 2.0 consortium and establish baseline durability of most active
national lab core-team catalyst, e.g., LANL’s CM-PANI-Fe-C(Zn), (AD)Fe-N-C, or
ANL’s Fe(N-C), using differential cell and ElectroCat AST protocol.
12/31/2020
Quarterly Progress
Measure (Regular)
Completed,
see slides
#7 & 8
Apply machine-learning techniques to develop surrogate regression models of ANL
high-throughput data for metal loading and ratio of two different carbon-nitrogen
precursors and propose 12 validation experiments. After synthesis and activity
evaluation of the 12 suggested catalysts using high-throughput methodology, update
surrogate regression model and provide a ‘Design of Experiments’ suggesting 6
additional, optimized “next-step” experiments for optimizing catalyst activity.
3/30/2021
Quarterly Progress
Measure (Regular)
Completed;
see
slide #19
Demonstrate H2-air performance with PGM-free cathode MEA of ≥ 60 mA/cm2 at
0.8 V and ≥ 300 mA/cm2 at 0.675 V at beginning-of-test and ≤ 50% and ≤ 40% loss
in current density at 0.8 V and 0.675 V, respectively, after 30,000 AST cycles under
differential conditions.
06/30/2021
Quarterly Progress
Measure (Regular)
On track;
see slide #31
for Summary
of Status
LTE: Achieve 0.7 A cm-2 with LTE electrolyzer PGM-free anode at 1.85 V and
degradation rate ≤ 0.15 mV/h with pure water reactant.
09/30/2021
Annual Milestone
(Regular)
TBD
PEFC: Hydrogen-oxygen performance: Achieve PGM-free cathode MEA
performance in an H2-O2 fuel cell of 35 mA cm-2 at 0.90 V (iR-corrected) at 1.0 bar
partial pressure of O2 and cell temperature 80 °C.
09/30/2021
Annual Milestone
(Regular)
GPRA
Exceeded,
38 mA cm-2;
see slide #5

GPRA FY20 and FY21 Annual Milestones Exceeded with ‘Single-Zone’ Fe-N-C Catalyst
Cathode: ca. 7.0 mg cm-2, NH4Cl activated ‘single-zone’ Fe-N-C catalyst, 1700 sccm, 1.0 bar O2 partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C H2, 700 sccm,
Full Cycle i at 0.9 ViR-corrected (mA/cm2)
41 mA/cm2 (1st cycle)
1st 41
2nd 38
3rd 36
Average 38
1.0 bar H2 partial pressure, 100% RH; Membrane: Nafion,211; Cell: differential, 2.5 cm2; Temperature: 80 °C
Test conditions: 80 °C; cycle: 0.96 V to 0.88 V in 20 mV steps; 0.88 V to 0.72 V in 40 mV steps; 45 s/step.
50
40
30
20
10
0
Number of cycles
• Highlight: FY20 Annual Milestone of 35 mA/cm2 0.9 V
(iR-corrected) exceeded at 38 mA/cm2 (average value from
three full cycles) with LANL’s ’single-zone’ Fe-N-C catalyst
• 27% improvement of in fuel-cell activity relative to FY19
(30 mA/cm2, average from three full cycles)
• 41 mA/cm2 average current density achieved in initial cycle
Current
density
at
0.90
V
iR-corrected
(mA/cm
2
)
1st 2nd 3rd
2019
2020

Catalyst Development: ‘Single-Zone’ and ‘Dual-Zone’ Catalyst Synthesis
Precursor synthesis:
Fe(NO3)3 ∙ 9H2O
Zn(NO3)2∙6H2O
+
24 h
Drying
N2
‘Single-zone’ synthesis:
Single Zone
Inlet Outlet
MOF precursor
‘Dual-zone’ synthesis:
Inlet
Zone 1 Zone 2
N-C precursor
(source)
Outlet
MOF precursor
(target)
N2
Zn
Fe
N
C
NH4Cl-activated
‘single-zone’
Fe-N-C
NH4Cl
‘Single-zone’
Fe-N-C
‘Dual-zone’
Fe-N-C
• Fe-N-C catalysts derived from bimetallic
(Fe, Zn) zeolitic imidazolate frameworks
• ‘Single-zone’ catalyst synthesis followed
by NH4Cl activation
• ‘Dual-zone’ synthesis involving deposition
from zone 1 to zone 2 (zone temperatures
controlled independently)

FY21 Q1 GPRA Milestone: Durability Baseline for PGM-free Catalysts (‘Single-Zone’ Fe-N-C Catalyst)
1 1
0.8
MEA #1 - initial
MEA #2 - initial
MEA #1 - 30k cycles
MEA #2 - 30k cycles
H2-air
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
MEA #1 - initial
MEA #2 - initial
MEA #1 - 30k cycles
MEA #2 - 30k cycles
H2-O2
0 0.05 0.1 0.15 0.2
iR-corrected
voltage
(V)
0.9
0.8
Voltage
(V)
0.6
0.4
0.2
0
Current density (A/cm2
) Current density (A/cm2
)
H2-air H2-O2
Cycle
number
MEA #1
i (mA/cm2)
0.8 V 0.675 V
V (V)
0.8 Acm-2
MEA #2
i (mA/cm2)
0.8 V 0.675 V
V (V)
0.8 Acm-2
Cycle
number
0
i at 0.90 ViR-free (mA/cm2)
MEA #1 MEA #2
16 14
0 68 353 0.52 71 381 0.54 30k 0 0
30k 18 171 0.41 18 184 0.43
Cathode: ca. 4.0 mg cm-2, ‘single-zone’ Fe-N-C catalyst, 1700 sccm, 1.0 bar air/O2 partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 700 sccm, 1.0 bar H2 partial
pressure, 100% RH; Membrane: Nafion 211; Cell: differential, 5 cm2, Temperature: 80 °C; Durability cycling: (OCV-0.01 V) to 0.60 V (see slide #19 from 2020 AMR)
• Highlight: GPRA Milestone achieved using LANL’s ‘single-zone’ Fe-N-C catalyst in two MEAs with very reproducible performance
• Durability baseline established using PGM-free protocols developed in ElectroCat in FY20

JiaNC_FeAC_BOT
Ji _
Ji _ k
Ji _ k
Ji _
Ji _
JiaNC_FeAc_BOT
JiaNC_FeAc_30k
FY21 Q1 GPRA Milestone: Durability Baseline for PGM-free Catalysts (High-Throughput Fe(N-C))
Cathode: 3.2 mg cm-2, FeAc(N-C), 1700 sccm, 1.0 bar air/O2 partial pressure, 100% RH; Anode: 0.2 mgPt cm-2 Pt/C, H2, 700 sccm,
1.0 bar H2 partial pressure, 100% RH; Membrane: Nafion211; Cell: differential, 5 cm2, Temperature: 80 °C; Durability cycling: (OCV-0.01 V) to 0.60 V
1 0.94
0.8
0.9
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
H2-Air
aNC FeAC_100
aNC FeAC_1
aNC FeAC_5
aNC FeAC_10k
aNC FeAC_30k
Initial
100
1k
5k
10k
30k
H2-O2
Initial
30k AST Cycles
iR-corrected
Voltage
(V)
0.86
0.82
Voltage
(V)
0.6
0.4
0.2
0.78
0
0 0.04 0.08 0.12 0.16 0.2
Current Density (A/cm2)
Current Density (A/cm2)
H2-N2 Cyclic Voltammogram
• H2/Air beginning of life performance: • H2/O2 beginning of life activity:
Current
Density
(mA/cm
2
)
20
15
10
5
Initial
30k AST Cycles
 55 mA/cm2 at 0.8 V  9 mA/cm2 at 0.9 ViR-free
 340 mA/cm2 at 0.675 V  162 mA/cm2 at 0.8 ViR-free
• Loss in H2/Air current density after 30k • H2/O2 activity after 30k AST cycles: 0
AST cycles:  0 mA/cm2 at 0.9 ViR-free
-5
 84% at 0.8 V  32 mA/cm2 at 0.8 ViR-free
-10
-15
 64% at 0.675 V
-0.1 0.1 0.3 0.5 0.7 0.9 1.1
Potential (V vs anode)

1
0.8
0.2
Major Progress in Catalyst Durability: LANL ‘Dual-Zone’ vs. ‘Single-Zone’ Fe-N-C Catalysts
Cathode: ca. 4.0 mg cm-2, ‘single-zone’/‘dual-zone’ Fe-N-C catalyst, 1700 sccm, 1.0 bar air partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 700 sccm, 1.0 bar
H2 partial pressure, 100% RH; Membrane: Nafion 211; Cell: differential, 5 cm2, Temperature: 80 °C; Durability cycling: (OCV-0.01 V) to 0.60 V
1 1 1
• Highlight: ‘Dual-zone’ approach
0.8 0.8 0.8 resulting in a major durability
Initial
20k cycles 40k cycles
‘Dual-Zone’ Fe-N-C #1
0 0.2 0.4 0.6 0.8 1 1.2 1.4
)
Initial
‘Single-Zone’ Fe-N-C
0 0.2 0.4 0.6 0.8 1 1.2 1.4
HFR
(
Ω
cm
2
)
HFR
(
Ω
cm
2
)
HFR
(
Ω
cm
2
)
Voltage
(V)
Voltage
(V)
improvement relative to
Fe-N-C catalysts obtained via
standard single heat treatment
• Current density loss after 80k
0.6 0.6
0.6 0.6
0.4 0.4 0.4 0.4
0.2 0.2 0.2
cycles with ‘dual-zone’ catalyst
0 0 0 0 limited to 23% at 0.8 V and 6%
) at 0.675 V, compared to 94%
and 83%, respectively, with the
1 1 reference ‘single-zone’ catalyst
V (V)
0.675 V 0.8 A cm-2
i (mA/cm2) V (V)
0.8 V 0.675 V 0.8 A cm-2
247 0.49
129 0.38
83 0.32
63 0.28
43 0.24
31 181 0.32
31 206 0.33
28 195 0.34
26 180 0.31
24 170 0.32
Initial 10k cycles
0 0.2 0.4 0.6 0.8 1 1.2 1.4
)
• Excellent performance
reproducibility demonstrated
with two batches of ‘dual-zone’
Fe-N-C catalysts, one
0.8 0.8
Voltage
(V)
0.6 0.6
0.4 0.4
synthesized in FY20 and the
0.2 0.2 other in FY21, attesting to high
repeatability of the used
0 0
synthesis approach
Cycle
#
20k
0
40k
60k
80k
i (mA/cm2)
‘Single-Zone’ Fe-N-C
0.8 V
36
13
7
4
2

Catalyst Durability: ‘Single-Zone’ and ‘Dual-Zone’ Catalysts
Cathode: ca. 4.0 mg cm-2, ‘single-zone’/‘dual-zone’ Fe-N-C catalyst, 1700 sccm, 1.0 bar N2 partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 700 sccm, 1.0 bar
H2 partial pressure, 100% RH; Membrane: Nafion,211; Cell: differential, 5 cm2, Temperature: 80 °C
40 40
30 30
Initial
20 mV/s, H2-N2
‘Single-Zone’
0.0 0.2 0.4 0.6 0.8 1.0
20 mV/s, H2-N2
Initial
‘Dual-Zone’
Current
density
(
mA/cm
2
)
20
10
0
-10
Current
density
(
mA/cm
2
)
20
10
0
-10
-20 -20
-30 -30
0.0 0.2 0.4 0.6 0.8 1.0
Potential (V) Potential (V)
Estimated area* (m2/g) • Highlight: Increase in the surface area* of the
Cycle number
‘dual-zone’ catalyst during cycling significantly
‘Single-Zone’ ‘Dual-Zone’
less than of the ‘single-zone’ Fe-N-C catalyst
Initial 572 502
• Little carbon corrosion detected during cyclic
20k 838 513
voltammetry of the ‘dual-zone’ Fe-N-C catalyst
40k 880 523
• Very large initial corrosion current measured
60k 906 546
above 0.8 V for ‘single-zone’ Fe-N-C catalyst
80k 942 527
* Surface area estimated from double-layer capacitance

X-ray Absorption Spectroscopy Characterization of ‘Dual-Zone’ Catalyst
• While ‘Dual-Zone’ Fe-N-C catalyst does not show prominent Fe redox features in the cyclic voltammogram, in situ X-ray
absorption spectroscopy shows that there are major changes in the Fe oxidation state over the same potential region as
other catalysts showing prominent redox features
• Potential at which 50% of high potential Fe species is reduced: 0.6 V vs RHE
Fe K-edge EXAFS, LANL “Dual-Zone”
Catalyst, Deaerated 0.5 M H2SO4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
7100 7110 7120 7130 7140 7150 7160
Normalized
xµ(E)
900mV 800mV
700mV 675mV
650mV 625mV
600mV 550mV
500mV 400mV
300mV 0mV
Potential V vs. RHE
Decreasing
Potential
Cyclic Voltammograms in
Deaerated 0.5 M H2SO4, 10 mV/s
X-ray Energy (eV)

2 nm
Identical Location Scanning Transmission Electron Microscopy (IL-STEM) of ‘Dual-Zone’ Catalyst
Experimental Setup Square-wave Protocol
2.5s 0.5s
Gas
bubbler
Counter
electrode:
Reference
electrode
Working
electrode
0.9 Vvs. RHE
15,000 cycles
@ 80oC
Air (no purge)
0.05M H2SO4
0.6 Vvs. RHE
2.5
s
STEM-EDS (at.%)
BOL 15k • IL-STEM method implemented to elucidate degradation
mechanisms
C 96.8 94.6
• Cycling performed with catalyst on Au TEM grid in
1.38 1.39
N
aqueous three-electrode cell
1.77 3.9
O
• Composition (EDS) and carbon morphology (EELS) of
0.07 0.05
Fe
identical region quantified at BOL and 15k cycles
0.03 0.01
Zn
2 nm

Characterization of ‘Dual-Zone’ and ‘Single-Zone’ Fe-N-C Catalysts
‘Dual-Zone’ compared to ‘Single-Zone’ catalyst:
• No Fe redox features in background voltammetry
• Less NO adsorbed (1.7×) (i.e., fewer adsorption sites)
• Identical Fe K-edge X-ray absorption spectra: same Fe
coordination environment
• More N (3.8×) and more oxygen (1.7×) by EDS
• Hypothesis: N-C deposit on ‘single-zone’ catalyst decreases
adsorption on sites adjacent to Fe-Nx centers which are
vulnerable to attack by oxidants*
*Reference: P. Boldrin et al., Appl. Catal. B: Environ. 292 (2021) 120169.
EDS Analysis of Single-Zone and Dual-Zone Catalysts (at%)
Element Single-Zone Dual-Zone
Fe 0.05 0.06
Zn 0.01 0.05
C 98.69 96.94
N 0.38 1.43
O 0.89 1.52
Gas-phase Adsorbed NO Temperature-Programmed Desorption
Single: 1.6 1021 NO/gcat
Dual: 9.3 1020 NO/gcat
Fe K-edge X-ray Absorption Spectroscopy

High-Throughput Synthesis and Characterization of ORR Catalysts
Synthesis Characterization
Multi-port CVD
• Combining N-C and Fe and Co salts, followed by heat treatment
 Incorporation of porogens to improve mesoporosity
 Increasing N content of N-C through C-N precursors and ammonia treatment
• Chemical vapor deposition of Me (Me=Fe, Co, etc.) into vacancies in N-C
• Deposition of N-C layer over Me-N-C to improve stability
• Quenching to increase atomically-dispersed Fe-N-C content, preventing Fe carbide
and Fe cluster formation

High-Throughput Synthesis of ORR Catalysts
Catalyst System 1: Solution phase synthesis of (Fe)Zn – ZIF; 40 unique samples
Catalyst System 2: Physical mixtures (ball milling) of Fe salt, carbon-nitrogen precursor, carbon support
(e.g., Zitolo et al., Nat. Mater., 14, 937, 2015)
• Seventy-four catalyst samples with varying phenanthroline-to-ZIF ratios and varying content of Fe in the precursor were
prepared for input into machine learning activity since 2020 AMR
Catalyst System 3: Two step synthesis; formation of nitrogen-doped carbon followed by incorporation of Fe
(based on J. Li, D. Myers, Q. Jia et al., J. Am Chem. Soc., 142, 1417, 2020)
• Physical mixtures (ball milling) of carbon-nitrogen precursors pyrolyzed and heat-treated in NH3 to form nitrogen-doped
carbon (N-C)
• Physical mixtures (ball milling) of N-C and Fe salt pyrolyzed and heat treated in NH3
• Parameters varied to obtain 102 unique samples since FY20 AMR:
 Addition and amount of CeO2 before or after heat treatment of FeCl3/N-C precursors
 Use and concentration of H2 rather than NH3 in the second heat treatment step
 Addition and concentration of porogens: ZnCl2, cyanamide, and NH4Cl
Catalyst System 3b: Chemical vapor deposition of FeCl3 into N-C
(based on J. Li, D. Myers, Q. Jia et al., Nature Materials, accepted)
 Effect of ball-milling time of N-C (5 samples)
 Effect of heat treatment temperature (12 samples)

ORR Activity of High-Throughput System 2 Catalysts
RDE-determined ORR mass activity at 0.8 V and half-wave potential for System 2 catalysts prepared in ANL high-throughput activity for
input into machine learning activity. O2-saturated 0.5 M H2SO4, 0.6 mgcat/cm2
• Varied Fe wt% in precursors from 0.1 to 1 wt% and
Phenanthroline to ZIF-8 wt ratio from 50:50 to 0:100
• Activity and electrochemical surface area trends with
increasing ZIF-8 content indicate ZIF-8 is limiting
component in precursor
• Highest ORR mass activity observed for highest Fe
content (1 wt% Fe) and with no phenanthroline:
9.1 A/gcat @0.8 V
• ORR mass activity reported in literature for this class
of catalysts: 2.8 A/gcat at 0.8 V*
• Exploring heat treatment temperature ramp rates
(both heating and cooling), hold times, and higher Fe
contents (based on machine learning findings)
• Machine learning guidance for System 2 has
resulted in an increase in ORR mass activity to 12.4
A/gcat at 0.8 V (increased Fe content, among
changes in other variables)
*Reference: Primbs et al., Energy Environ. Sci., 2020, 13, 2480-2500.

ORR Activity of High-Throughput System 3, 3b Catalysts
RDE-determined ORR mass activity at 0.8 V; O2-sat. 0.5 M H2SO4, 0.6 mgcat/cm2
ORR
Activity
@
0.8
V
(A/g-cat)
• System 3b: Multi-port parallel reactor system
10
9 (Avantium T1224) for high-throughput exploration of
8
parameters in chemical vapor deposition synthesis
7
6 process
5
4
3
2
1
0
0
2
4
6
8
10
12
14
ORR
Activity
@
0.8
V
(A/g-cat)
System 3
• Addition of ceria increased ORR activity, higher than ZnCl2 and
cyanamide series; lowest peroxide yields: <3%
• Highest ORR activity observed for Fe/N-C mixture of 10 A/gcat (@0.8 V) for
catalyst derived from NH4Cl, treated in hydrogen, and with CVD of ZIF-8
System 3b
• Highest ORR activity of 13 A/gcat achieved using CVD of Fe into N-C with
deposition temperature of 800 °C with ball-milled N-C; peroxide yield 1.3%

Approach: Data-Driven Guidance of High-Throughput Synthesis of PGM-free Electrocatalysts
System-2 Data
System 2 (ball milled) Data from High-throughput
Combinatorial Synthesis Capability:
• 48 unique batches synthesized at 1050 °C
• Fe loading varied from 0.1 to 1% (wt%) and Phen : ZIF
ratio from 0 to 50% (wt%)
Neural network-based surrogate model:
• Deep learning (4 hidden layers with 100 neurons / layer)
• Model is optimized by minimizing RMS error with
iterative algorithm
• Design of experiment using active learning loop
Predictive guidance to improve next experiments
• What experiments efficiently explore search
space to optimize ORR activity and improve
the synthesis process?
• Quantify role of thermal profile next

FY21 Q2 Machine Learning GPRA Milestone: Met and Exceeded
Past Success (FY20): 36% Improvement in ORR Activity of System 1 Catalysts
using Machine Learning (ML)
• Developed ML-based surrogate model using 36 System 1 catalysts synthesized in high-
throughput task
• Constructed design-of-experiment and predicted synthesis conditions for increasing the
ORR activity
• Validated and improved electrocatalyst experimentally realized
FY21 Q2 GPRA Milestone:
Apply machine learning techniques to develop surrogate regression models of high-throughput data for metal
loading and ratio of two different carbon-nitrogen precursors and propose 12 validation experiments. After synthesis
and activity evaluation of the 12 suggested catalysts using high-throughput methodology, update surrogate
regression model and provide a ‘Design of Experiments’ suggesting 6 additional, optimized “next-step” experiments
or optimizing catalyst activity.
 Applied machine learning techniques to develop surrogate regression model
 Proposed (12 + 20) validation experiments and updated machine learning models
 Suggested (6 + 30) additional experiments to optimize catalyst activity

Data Driven Approach to Guiding High-Throughput Synthesis of PGM-free Electrocatalysts
Neural network-based surrogate Neural network activity heatmap
model validation – Design of Experiment (DoE)
Predicted
mass
activity
at
0.8
V
(A/g)
Highlight: Identified high Fe loading/low phen region not discovered in original
optimization dataset, highlighting usefulness of DoE / Active Learning approach
Max. initial
System 2
ORR = 4.97
A/g
0.8% Fe loading
and 40% Phen/ZIF
Max. from
ML/Active
Learning
model
ORR = 9.05
A/g
1.0% Fe loading
and 0% Phen/ZIF
Experimental mass activity at 0.8 V (A/g)

DFT/MD-based Stability Descriptor: KODTE for C/N Corrosion
• Atomistic models of electron beam damage can be used to probe how atomic scale structure affects C/N corrosion susceptibility.
• Knock-on displacement threshold energies (KODTE) represent an estimate of how much kinetic energy must be transferred to an
atom in a lattice in order to liberate it from its bound state (i.e., the kinetics of bond breaking).
• KODTE values can be used to understand the relative C/N corrosion susceptibility of PGM-free active sites at the atomic scale.
Elastic energy transfer
Knock-on displacement AIMD KODTE as a function of z
𝜃𝜃
𝑀𝑀, 𝑣𝑣
𝑚𝑚, 𝐸𝐸𝑑𝑑
𝑒𝑒−
𝐸𝐸𝑚𝑚𝑚𝑚𝑚𝑚 ≪ 𝐸𝐸𝑑𝑑
�
𝐸𝐸𝑑𝑑 ≈ 𝐸𝐸𝑑𝑑
Elastic scattering displacement at T = 0K
Knock-on displacement of N atom at edge (zigzag)
hosted FeN4 w/ KODTE 70 keV at T = 0K
N@FeN4 zigzag
Highlight: Developed a method to derive KODTE as a function of temperature and built a framework
to calculate durability descriptors for C/N atoms by implementing AIMD and DFTB MD simulations.
Susi et al. Nature Reviews 1, 397 (2019)
AIMD simulations of varied 𝐸𝐸𝑑𝑑 to determine when
an atom is knocked off
�
𝐸𝐸𝑛𝑛 𝐸𝐸𝑑𝑑, 𝜃𝜃 = 180°, 𝑣𝑣 =
(2 𝐸𝐸𝑑𝑑(𝐸𝐸𝑑𝑑 + 2𝑚𝑚𝑐𝑐2) + 𝑀𝑀𝑣𝑣𝑐𝑐)2
2𝑀𝑀𝑐𝑐2

DFT/MD-based Stability Descriptor: KODTE at Finite Temperature
Displacement distribution MD simulations at T =100 K Velocity distribution
(2 𝐸𝐸𝑑𝑑(𝐸𝐸𝑑𝑑 + 2𝑚𝑚𝑐𝑐2) + 𝑀𝑀𝑣𝑣𝑐𝑐)2
𝐸𝐸
�𝑛𝑛 𝐸𝐸𝑑𝑑, 𝑣𝑣 =
2𝑀𝑀𝑐𝑐2
KODTE (v(T=100K, 300K))
𝜇𝜇 = 69.33 𝜇𝜇 = 69.21
𝜎𝜎 = 2.46 𝜎𝜎 = 3.41
Highlight: 60 keV electrons calculated to damage PGM-free active site structures at room temperature

DFT-based Stability Descriptor: Metal Dissolution
• Initial model suggests ligand passivation
• 5th ligand impacts both ORR activity as well
as stability
• Explains previously mysterious experimental
stability trend
 Dissolution at lower potentials and
stable at higher potentials
• Further improvements of model underway:
 New H2O, H2, and O2 reference states
 Zero-point energy models
 Solvation effects
 Vibrational entropy models
 Additional reactions (67)
• Modified sites, transition metals,
dissolved ionic species, and ligating
moieties
Highlight: Published initial, first-of-its-kind Pourbaix-like diagram for PGM-
free active site metal dissolution in ACS Catalysis
Holby, Wang, and Zelenay, ACS Catalysis 10, 14527 (2020).

DFT Screening Adsorption of Reactants/Ligands/Poisons on Graphene-Hosted FeN4
• Qualitative maps of which species either remained
bound to the surface or desorbed
• Most species only bind to Fe
• Some species exhibit stronger potential-dependent
binding energy shifts than others
• Competitive adsorption to Fe
 OH can favorably bind to C sites
Highlight: Potential-dependent binding energies of six moieties on model active
site structure calculated: potential dependence varies across binding species.

New Machine Learning Efforts in ElectroCat
• Multi-Objective Optimization (MOO):
 Pareto-front-based machine learning approach is
being developed for two-objective optimization:
Durability vs. Activity
 Optimize atomic scale structures based on DFT-
based descriptors of activity and durability and couple
with experimental data where possible
• Multi-fidelity Optimization (MFO):
 Multi-fidelity surrogate models for binding energy and
other chemical-reaction descriptors are being
developed using lower-fidelity (high throughput) DFT
and higher-fidelity random phase approximation
(RPA) simulated data.
 Collaboration between LANL and NREL theory efforts
 First model: NO binding motifs on FeN4 structures

Multi-fidelity Optimization (MFO): Modeling FeN4 with NO Ligation
DFT - GGA
• Started high-fidelity potential energy surface
calculations of NO binding to graphene-hosted
FeN4 active site
 1st model system – applicable to NRVS
and “probe molecule” experimental studies
 Needed for MFO approach
• RPA simulations computationally expensive ➝
Can we map from less expensive DFT
calculations of binding energies to RPA using
machine learning approaches?
 Start with system energy as a function of
Fe-N-O bond angle and Fe-N N-O dihedral
angle
• Initial results: RPA energies are more sensitive
to structure than DFT
RPA
Fe-N-O bond angle
Fe-N N-O dihedral angle

LANL_HZ_single_Fe
NC
LANL_HZ_single_Fe
NC_030120
Probe Molecule Study of ‘Single-Zone’ Catalyst
Gas-phase adsorbed NO stripping voltammetry ORR voltammetry before and after
in deaerated 0.5 M H2SO4, 10 mV/s electrochemical NO stripping
0
1.5
1
-1
RDE:
0.6 mgcat/cm2 LANL Single-Zone Catalyst
O2-sat 0.5 M H2SO4
Staircase voltammetry
Blue: NO poisoned
Red: After NO stripping
Current
Density
(mA/cm
2
) 0.6 mgcat/cm2 LANL Single-Zone Catalyst
NO stripping
Current
Density
(mA/cm
2
)
-2
-3
-4
-5
0.5
0
-0.5
-1
-1.5
-2
-2.5
-3
-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2
_030120
0 0.2 0.4 0.6 0.8 1
Potential (V vs. RHE) Potential (V vs. RHE)
NO adsorption/stripping site density:
• 1.3 x 1020 sites/gcat (3 e- NO reduction)1
• 7.6 x 1019 sites/gcat (5 e- NO reduction)2
Highlight: Achieved 4× increase in adsorption site density compared to (AD)Fe-N-C and 5× versus literature benchmark data3
1Reference: D.H. Kim, et al. “Selective electrochemical reduction of nitric oxide to hydroxylamine by atomically dispersed iron catalyst.”, Nat. Commun. (in press).
2Reference: D. Malko, A. Kucernak, and T. Lopes, “In situ electrochemical quantification of active sites in Fe–N/C non-precious metal catalysts.”, Nat. Commun., 7, 13285 (2016).
3Reference: M. Primbs et al., Energy Environ. Sci., 13, 2480-2500 (2020).

N2 background
subtracted CV
0.1 V/s
O2
NaNO2 Probe Poisoning of Pajarito Powder Catalyst
Poisoning
Baseline 1) H2O Post Poisoning Recovery
CV: O2, N2, N2* 2) 0.125 M NaNO2
Baseline CV: O2, N2, N2*
CV: O2, N2, N2*
3) 0.5 M H2SO4
1 V to 0.3V vs RHE * 0.6 V to -0.3V vs RHE
4) H2O
Increasing
Active
Site
Density
Untreated Acid Treated After 1,000 cycles
SD
Catalyst
(sites cm-2)
Pajarito 0.9 0.14 31 317 3.9 × 1019 1.3 × 1013
Acid-treated
0.9 0.06 47 359 5.8 × 1019 1.9 × 1013
Pajarito
Cycled
0.9 0.05 257 1029 3.2 × 1020 4.6 × 1013
Pajarito (1k)
Decreasing
Activity
Poisoning
Potential
(V vs RHE)
Qstrip MSD
∆ E1/2 (V) SA (cm2)
(C g-1) (sites g-1)
Ink preparation: 5 mg catalyst, 500
µL IPA, 20 µL 5 wt% Nafion; Catalyst
Loading: 0.6 mg cm-2 Pajarito 87-13
Electrochemical Conditions: 0.5 M
H2SO4, 1600 rpm, O2
• Catalyst activity
decreases after acid
treatment and cycling
• Calculated site
density from the
nitrite stripping
increases after
catalyst treatment
• Highlight: Nitrite
probe is not active
site-specific (binding
to non-active sites)

Capability Development: O2 Limiting Current Method for Characterization of Bulk Electrode Transport
HOR Limiting Current
• HOR Limiting Current: Hydrogen diffusing through
PGM-free cathode and oxidized on Pt black sensor between
membrane and cathode
• HOR limiting current method does not capture transport
changes due to water production, as is observed in
operating cathodes
ORR Limiting Current
• ORR Limiting Current: O2 reduced on Pt black sensor
• Use of diffusion media (GDL) between sensor layer and
probed layer inhibits ionic transport shutting off ORR
response from PGM-free electrode
• Addresses shortcoming of hydrogen method: water is
produced on Pt sensor
Highlight: Capability developed to understand oxygen transport through thick PGM-free cathodes independent of ionic
transport in cathode

Capability Development: Electrochemical Diagnostics for Determining Electrode Transport Properties
H2/air polarization curves measured at 80oC and 150 kPa for MEAs fabricated with Pajarito PMF-
011904 electrocatalyst at different I/C ratios and ionomer EWs under (A) 100% RH, (B) 75% RH
Rtotal HOR Limiting Current Rtotal ORR Limiting Current
Nafion
1100 EW
Aquivion Ionomer,
Nafion
Aquivion 720 EW I/C=1.0
1100 EW Ionomer,
720 EW
Ionomer, I/C=1.0
Ionomer,
I/C=0.54
I/C=0.54
• Bulk electrode transport resistance >> local resistance in PGM-free
cathodes (unlike low-PGM cathodes)
• Hydrogen oxidation (HOR) limiting current does not capture effects of water
production on bulk transport
• Oxygen limiting method captures effects of water production and shows
detrimental impact of water on oxygen transport
• Observed bulk oxygen transport dependence on ionomer EW and RH
explained by different extents of ionomer swelling in cathode catalyst layer
PFSA thin film ionomer swelling data from Kusoglu et
al., Adv, Func. Mater., 26 (2016) 4961.

- -
-
ElectroCat Status: PGM-free Catalysts in H2-Air and H2-O2 Fuel Cells
Catalyst
H2-air fuel cell
Initial After 30k cycles1
i (mA/cm2) V (V) i (mA/cm2) V (V)
0.8 V 0.675 V 0.8 A cm 2 0.8 V 0.675 V 0.8 A cm 2
ANL Fe (N-C) 2020 AMR2
54 246 0.40 15 121 0.32
ANL Fe (N-C) 2021 AMR 55 340 0.56 9 122 0.44
LANL ‘Dual-Zone’ Fe-N-C3
31 181 0.32 24 170 0.32
LANL ‘Single-Zone’ Fe-N-C 72 381 0.53 19 185 0.43
LANL (AD)Fe1.5-N-C 37 211 0.44 3 47 0.28
LANL CM-PANI-Fe-C(Zn)2,4
105 440 ~ 0.47 not cycled
1 AST cycles in air (0.2 bar partial pressure of O2), voltage range from 0.6 V to OCV; 2 Non-differential conditions; 3 After 80k AST cycles; 4 No AST cycling performed.
Catalyst
H2-O2 fuel cell
1
i (mA/cm2) at 0.9 ViR free
Initial After 30k cycles
ANL Fe (N-C) 2021 AMR 9 0
LANL ‘Single-Zone’ Fe-N-C 15 0
LANL CM-PANI-Fe-C(Zn) 30 not cycled
LANL NH4Cl-activated Fe-N-C 38 not cycled
1 Average current density from three consecutive cycles.

Low Temperature Electrolyzer (LTE): Introduction and Work Scope
Liquid Alkaline Electrolyzer
Advantages:
• Easy concept: no need of solid polymer
electrolyte
• Use of PGM-free catalysts (Ni- and Fe-based)
Drawbacks:
• Use of concentrated alkaline solution
• Component corrosion
PEM Electrolyzer
Advantages:
• Use of pure water
• Use of well-established PFSA (Nafion)
H+ membrane and ionomer
Drawbacks:
• Use of PGM-based catalysts (Ir on
anode, Pt on cathode)
AEM Electrolyzer
Advantages:
• Use of pure water
• Use of PGM-free catalysts
Drawback:
• Dependence on “research-
scale” AEMs and ionomers
(not yet commercial on large
scale)
 Synthesis of OER catalysts for AEM LTEs
 Testing of PGM-free OER catalysts from external partners
 Performance, durability, and advanced diagnostic studies of LTEs
 High-throughput synthesis and characterization of OER catalysts based on
perovskite oxides A1-xBxO3
 Advanced characterization of OER catalysts
Milestone: Achieve 0.7 A cm-2 in LTE with PGM-free anode at 1.85 V and degradation rate ≤ 0.15 mV/h with pure water.
Go/No-Go: Review performance and durability of two LTE anode catalyst classes for acidic and alkaline environments,
ZIF-derived multi-metallic oxides and bimetallic Ni-based alloys, respectively. Down-select to catalyst class with more
promising performance with option to continue its development in Years 2 and 3. Current density of ≥ 300 mA/cm2 at 1.8 V
and degradation rate of ≤ 0.15 mV/h in 100 h with pure water feed.

Water LTE Testing: LANL LSC and WSU Catalysts
LANL LSC: La0.85Sr0.15CoO3-δ (perovskite) synthesized at LANL; WSU: Ni2Fe1 nano-foam catalyst from Washington State University
Anode: 5 mg cm-2 catalyst, Cathode: 2 mg cm-2, PtRu/C; AEM and ionomer: Hexamethyl trimethyl ammonium-functionalized Diels-Alder polyphenylene (HTMA-DAPP) from
SNL; Cell: 5 cm2 electrode area. AEM and ionomer “activated” by flushing with both electrode compartments with 1.0 M NaOH solution for a few minutes prior to the tests.
LTE Polarization Plots Durability Testing
2.4
2.6
LSC 2.3
2.4 WSU
2.2
Cell
Voltage
(V)
2.2
2.0
1.8 Go/No-Go
Cell
Voltage
(V)
2.1
2.0
1.9
1.8
1.7
1.6
1.4
1.5
Water feed at 60 °C
Water feed at 60 °C
1.4
1.2
LSC
1.6
WSU
0 200 400 600 800 1000 0 20 40 60 80 100 120 140
Current Density (mA cm-2
) Time (h)
• In testing using HTMA-DAPP ionomer: WSU catalyst performing better at low current densities; LSC
catalyst showing better performance at higher currents; performance approaching Go/No-Go point
• Further performance improvements expected with non-adsorbing, low-IEC ionomer (upcoming)
• Degradation rate at 200 mA cm-2 (relative to minimum-voltage point): 2.2 mV/h (WSU), 1.3 mV/h (LSC)

2.0
1.8
LTE Testing: Di-Jia Liu HydroGEN Seedling Project Catalyst
Cell
Voltage
(V)
Anode: 4 mgcm-2 catalyst, I/C = 0.5 Cathode: PtRu/C, 1.6 mgPt cm-2; Membrane and ionomer: HTMA-DAPP (from SNL); Cell: 5 cm2 electrode area
2.6 2.8
2.4 2.6
2.2 2.4
Cell
Voltage
(V)
2.2
2.0
1.6
1.4
water - 60°C
water - 70°C
water - 80°C
1.8
1.6
1.2
0 500 1000
-2
)
Current Density (mA cm
1500
1.4
0 2 4 6 8 10 12 14 16 18
Time (h)
20 22 24 26 28 30
• Good long-term stability of catalyst over 27-hour life test
• Degradation rate at 200 mA cm-2: ca. 1.25 mV/h (relative to minimum-voltage point)

Characterization of LANL La0.85Sr0.15CoO3-δ (LSC) Perovskite Catalyst
1 nm
La, Co overlay
La,Sr Co
• Initial aberration-corrected STEM
characterization performed on LANL LSC
catalyst
• Morphology consists of sintered 50 nm
single crystal particles
• Atomically-resolved STEM images and
energy dispersive X-ray spectroscopy
(EDS) maps confirm perovskite structure

Synthesis of Perovskite Oxide OER Catalysts Using High-Throughput Methodology
Synthesis Strategy and Goals: ABO3
• Maximize the use of the automated system: use soluble ABO3 precursors, metal
complexes
• Increase the porosity of the ABO3 structure via introducing a hard template
• Formation of a pure phase
• Hydrothermal synthesis has been chosen and has been adapted to high-throughput
platform*
Sample Set #1:
LaxSr(1-x)CoO3
Vary X
Sample Set #2:
Pressure Reactor
LaxSr(1-x)CoyFe(1-y)O3
Varying X and Y
* Hydrothermal synthesis on high-throughput
platform has been developed and implemented
within MIT-led ARPA-E Differentiate project

Alternative: Hierarchical Nanoporous OER Catalysts Derived from Multi-Cation MOFs
Multi-Cation MOF Crystals
M1, M2 = Ni, Co, Fe, Sn, etc.
MOF-M1
MOF-M2
Heat
Treatment
Hierarchical
Nanoporous
Catalyst
Aging
Growth
Non-Stoichiometric Oxides
Single Atom + Nanoparticles
Conductive Catalyst
Graphene-
Non-Stoichiometric
Conductive Oxides
Enhancing Electronic Conductivity of Perovskites
~5 nm layer of carbon coating a
graphene deposition assist layer (GrDA)
GrDA = component of proposed perovskites
• Utilize Argonne proprietary carbon deposition procedure, developed in FC 322,
to deposit a porous graphene layer on perovskites

Reviewers’ Comments from 2019 Annual Merit Review
Comments from 2019 AMR addressed in 2020 AMR presentation (see slides 44 and 45)














Collaboration and Coordination: Summary
• ElectroCat members: Four national laboratories:
Los Alamos National Laboratory – ElectroCat co-Lead
Argonne National Laboratory – ElectroCat co-Lead
National Renewable Energy Laboratory
Oak Ridge National Laboratory
• Support of ten FY2017 FOA, FY2019 FOA, FY2019 Lab Call projects (see next slide for lead organizations)
• Collaborators not directly participating in ElectroCat (no-cost):
CRESCENDO, European fuel cell consortium focusing on PGM-free electrocatalysis – development and validation of
PGM-free catalyst test protocols
PEGASUS, European fuel cell consortium targeting PGM-free fuel cells – development and validation of PGM-free
catalyst test protocols
Israeli Fuel Cell Consortium (IFCC) – PGM-free activity indicators and durability
Bar-Ilan University, Israel – aerogels-based catalysts with high active-site density

University at Buffalo (SUNY), Buffalo, New York – novel PGM-free catalyst synthesis (independent of two ElectroCat
projects involving UB)
Pajarito Powder, Albuquerque, New Mexico – catalyst scale-up, PGM-free electrode design, catalyst commercialization
(independent of ElectroCat project)
Technical University of Munich, Germany – catalyst development and characterization
University of Warsaw, Poland – role of graphite in PGM-free catalyst design
University of Toledo – hydrogen peroxide sensor
Washington State University – electrocatalyst for low-temperature elctrolyzer anode

Collaboration & Coordination: ElectroCat Projects
Core: FY2021 FY2017 FOA FY2019 FOA

Remaining Challenges and Barriers
• Fuel Cell
 Improving the performance of PGM-free polymer electrolyte fuel cell cathodes while
maintaining durability (e.g., ‘dual-zone’ catalyst).
 Comprehensive understanding of the catalyst and electrode degradation mechanism(s) in
order to successfully develop mitigation strategies
 Increasing the density of active sites and oxygen reduction reaction turnover frequency
(TOF) to meet DOE H2-air performance targets
 Reducing cathode proton resistance while maintaining high oxygen permeability
• Low-Temperature Electrolysis
 Increasing electrolyzer performance by a factor of 2.5
 Improving durability of alkaline membrane electrolyzer operating on pure water and at
temperatures of ≥ 60 °C
 Minimizing degradation of anion-exchange ionomers

Proposed Future Work
• ElectroCat Development
 Populate ElectroCat DataHub with published data and publish the datasets to the Materials Data Facility
(https://materialsdatafacility.org/)
• Improvement in Performance and Durability of Fuel Cell Catalysts and Electrodes
 Expand probe-molecule studies to degraded ElectroCat core team catalysts; implement selective desorption of probe
molecule; couple with ORR activity and vibrational spectroscopy characterization to determine adsorption sites of probe
molecule
 Further identify primary factors governing the durability of PGM-free catalysts and electrodes and continue to develop
means to prevent performance degradation
 Advance performance of catalysts by maximizing volumetric density and accessibility of active sites, through alternative
synthetic methods, in particular:
• Synthesize catalyst structure identified by DFT as being both active and stable (μ-nitrido Co-Fe center; see slide #30
from 2020 AMR)
 Optimize the fuel cell performance of the Fe (N-C) catalyst (from high-throughput System 3b) by subjecting it to high-
throughput ink optimization, cell testing, and associated ink characterization and cell diagnostics
 Complete characterization of ‘dual-zone’ catalyst to determine source of promising durability and develop method to
increase activity
• Electrolyzer Catalysts and Electrodes
 Establish LTE baseline performance in pure water using commercial materials (membranes and ionomers)
 Synthesize and evaluate the activity of 60 OER catalysts using high-throughput approaches

Accomplishments and Progress
• ElectroCat Development and Communication
 Consortium supporting nine FOA/Lab Call projects with ten capabilities
 Consortium-wide virtual meeting held on January 25-26, 2021; national laboratory ElectroCat 2.0 PEFC kick-off meeting
held February 23, 2021; ElectroCat 2.0 LTE kick-off meeting held March 23, 2021
 22 papers published
 Developed oxygen limiting current method with Pt black sensor for characterizing bulk oxygen transport in PGM-free
cathodes
 Developed identical location STEM for studying catalyst degradation mechanisms
• Progress in Performance and Performance Durability of PGM-free ORR Catalysts
 ElectroCat FY20 and FY21 Annual (GPRA) Milestones of PGM-free cathode MEA performance of at 0.90 V (H2/O2, iR-
free, average of three consecutive pol curves) exceeded: 38 mA cm-2
 Performance of hydrogen-air fuel cell with an atomically-dispersed Fe-N-C cathode catalyst improved from 54 to
72 mA cm-2 at 0.8 V and from 246 to 381 mA cm-2 at 0.675 V since 2020 AMR
 Performance durability of hydrogen-air fuel cell significantly improved: Voltage degradation at 0.8 A cm-2 of 0 mV after
80k AST cycles for ‘dual-zone’ catalyst versus 250 mV for baseline ‘single-zone’ catalyst
 Synthesized 193 unique catalysts using high-throughput approach, with 30% enhancement in ORR activity performance
improvement versus highest ORR activity reported for System 3 in 2020 AMR
• Progress in PGM-free OER Catalysts
 Established baseline performance of LANL perovskite, Washington State University NiFe, and ANL-Di-Jia Liu HydroGEN
seedling project (project P157) mixed oxide catalyst in alkaline exchange membrane electrolyzer

Co-Authors
PGM-free catalyst development, electrochemical and fuel cell testing, atomic-scale
modeling, machine learning
Piotr Zelenay (PI), Towfiq Ahmad, Bianca Ceballos, Hoon Chung, Hasnain Hafiz,
Yanghua He, Edward (Ted) Holby, Mohammad Karim, Ulises Martinez, Luigi Osmieri,
Xi Yin, Hanguang Zhang
High-throughput techniques, mesoscale models, X-ray studies, aqueous stability
studies
Debbie Myers (PI), Magali Ferrandon, Jaehyung Park, Xiaoping Wang, Nancy Kariuki,
Evan Wegener, A. Jeremy Kropf, Cong Liu, Rajesh Ahluwalia, Xiaohua Wang,
C. Firat Cetinbas, Ben Blaiszik, Marcus Schwarting
Advanced fuel cell characterization, rheology and ink characterization, segmented
cell studies
K.C. Neyerlin (PI), Hao Wang, Derek Vigil-Fowler, Jacob Clary, Luigi Osmieri
Advanced electron microscopy, atomic-level characterization, XPS studies
Dave Cullen (PI), Michael Zachman, Haoran Yu, Harry Meyer III, Shawn Reeves

Technical Back-Up Slide and
Additional Information

FY21 Q1 GPRA Milestone: H2-Air Fuel Cell Durability of ‘Single-Zone’ Fe-N-C Catalyst
Cathode: ca. 4.0 mg cm-2, ‘single-zone’ Fe-N-C catalyst, 1700 sccm, 1.0 bar air partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 700 sccm, 1.0 bar H2 partial
pressure, 100% RH; Membrane: Nafion 211; Cell: differential, 5 cm2, Temperature: 80 °C
1 1
MEA #1 - Initial
MEA #1 - 100 cycles
MEA #1 - 1k cycles
MEA #1 - 5k cycles
MEA #1 - 10k cycles
MEA #1 - 30k cycles
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
MEA #2 - Initial
MEA #2 - 100 cycles
MEA #2 - 1k cycles
MEA #2 - 5k cycles
MEA #2 - 10k cycles
MEA #2 - 30k cycles
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
0.8
Voltage
(V)
0.8
0.6
0.4
Voltage
(V)
0.6
0.4
0.2
0.2
0
) Current density (A/cm2
)
0
Cycle
number
MEA #1
i (mA/cm2)
0.8 V 0.675 V
V (V)
0.8 Acm-2
MEA #2
i (mA/cm2)
0.8 V 0.675 V
V (V)
0.8 Acm-2
0 68 353 0.52 71 381 0.54
100 59 316 0.50 60 342 0.52
1K 48 276 0.48 49 302 0.50
5k 34 232 0.45 35 259 0.48
10k 29 210 0.44 30 230 0.47
30k 18 171 0.41 18 184 0.43
Excellent agreement in H2-air fuel cell
performance of two MEAs used in
establishing durability baseline using
‘single-zone’ Fe-N-C catalyst

FY21 Q1 GPRA Milestone: H2-O2 Fuel Cell Durability of ‘Single-Zone’ Fe-N-C Catalyst
Cathode: ca. 4.0 mg cm-2, ‘single-zone’ Fe-N-C, 1700 sccm, 1.0 bar O2 partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 700 sccm, 1.0 bar H2 partial pressure,
100% RH; Membrane: Nafion 211; Cell: differential, 5 cm2, Temperature: 80 °C
1 1 1 1
Voltage
(V)
HFR
(
Ω
cm
2
)
MEA #1 - intial 1st cycle
MEA #1 - intial 2nd cycle
MEA #1 - intial 3rd cycle
MEA #1 - 30k 1st cycle
MEA #1 - 30k 2nd cycle
MEA #1 - 30k 3rd cycle
0 0.05 0.1 0.15 0.2
)
MEA #2 - initial 1st cycle
MEA #2 - initial 2nd cycle
MEA #2 - initial 3rd cycle
MEA #2 - 30k 1st cycle
MEA #2 - 30k 2nd cycle
MEA #2 - 30k 3rd cycle
0 0.05 0.1 0.15 0.2
0.8
HFR
(
Ω
cm
2
)
Voltage
(V)
0.9
0.9 0.6 0.6
0.4 0.4
0.8 0.2 0.8 0.2
0 0
)
Current density Average current density
MEA
at 0.9 ViR-free (mA/cm2) at 0.9 V (mA/cm2)
#1 – BOL 16
15 ± 1
#2 – BOL 14
#1 – 30k n/a
n/a
#2 – 30k n/a
0.8

200
100
4
FOA Support: CO2 Emission Measurements with PNNL Fe-N-C catalyst at 0.70 V
Cathode: ca. 4.0 mg cm-2, , PNNL-Fe-N-C , 200 sccm, 1.0 bar N2/air/O2 partial pressure, 100% RH; Anode: 0.3 mgPt cm-2 Pt/C, H2, 200 sccm, 1.0 bar H2 partial
pressure, 100% RH; Membrane: Nafion,211; Cell: serpentine flow field, 5 cm2, Temperature: 80 °C
CO2 Emission from PNNL Fe-N-C Cathode at 0.7 V H2-O2 Performance of PNNL Fe-N-C Catalyst
300 1 1
CO
2
emission
(ppm)
Current
density(mA/cm
2
)
HFR
(
Ω
cm
2
)
N2 air
PNNL-Fe-N-C - 0.7 V
PNNL-Fe-N-C - 0.7 V
0 5 10 15 20 25
Initial Intial_iR-free
23 h 23 h_iR-free
0 0.4 0.8 1.2 1.6 2 2.4
0.8
0
6
0.6 0.6
Voltage
(V)
0.4 0.4
0.2 0.2
0 0
)
2
0
Time (h)
0.8

Status of M-N-C Catalysts Performance and Durability in PEFCs
DOE target: DOE target:
≥ 44 mA/cm2 at 0.90 V ≤ 40% loss (voltage cycling)
DOE target: DOE target:
≥ 300 mA/cm2 at 0.8 V ≥ 1.5 A/cm2 at 0.675 V
“Status and Challenges for the Application of Platinum Group Metal-Free Catalysts in Proton Exchange Membrane Fuel Cells,”
L. Osmieri, J. Park, D.A. Cullen, P. Zelenay, D.J. Myers, K. C. Neyerlin, Current Opinion in Electrochemistry, 25 (2021) 100627-100638.

LTE Testing: Pajarito Powder OER50 Catalyst
OER50 catalyst is a perovskite oxide where Fe nominally substitutes part (25%) of the Co in the base LANL formulation
La0.85Sr0.15CoO3-δ  Nominal La0.85Sr0.15Co0.75Fe0.25O3-δ; synthesized by Pajarito Powder as scale-up of LANL synthesis method
Anode: 6 mgcm-2 catalyst, Cathode: PtRu/C, 1.6 mgPt cm-2; Membrane and ionomer: HTMA-DAPP (from SNL); Cell: 5 cm2 electrode area
2.8
2.6
2.6
2.4
2.4
2.2
Cell
Voltage
(V)
Cell
Voltage
(V)
2.0
1.8
2.2
2
1.6
1.4
water - 60°C
water - 70°C
water - 80°C
1.8
1.6
1.2
0 500 1000
-2
)
Current Density (mA cm
1500
1.4
0 10 20 30 40 50 60 70 80
Time (h)
90 100 110 120 130 140
• Good long-term stability of the Pajarito LTE catalyst (OER50) over 120-hour life test
• Degradation rate at 200 mA cm-2: 0.65 mV/h (relative to minimum-voltage point)

La Sr Co
CoOx
LSC
CoOx
LSC
CoOx
LSC
Conductivity Improvements in Modified-LSC Pajarito Powder OER49B Perovskite Catalyst
CoOx LSC
• Pajarito-modified LSC catalyst (OER49B)
showed improved surface area and conductivity
• Morphology consists of 50 nm LSC particles on
200 nm platelets of cobalt oxide (CoOx)
• CoOx platelets appear to improve dispersion of
LSC particles and conductivity

Publications (since 2020 AMR presentation submission)
1. “Porphyrin Aerogel Catalysts for Oxygen Reduction Reaction in Anion-Exchange Membrane Fuel Cells;” N. Zion, J. C. Douglin, D. A. Cullen,
P. Zelenay, D. R. Dekel, and L. Elbaz, Adv. Funct. Mater., 2100963 (2021).
2. “Stability of Atomically Dispersed Fe–N–C ORR Catalyst in Polymer Electrolyte Fuel Cell Environment”, R. K. Ahluwalia, X. Wang, L.
Osmieri, J-K Peng, C. F. Cetinbas, J. Park, D.J. Myers, H. T. Chung, and K. C. Neyerlin, J. Electrochem. Soc, 168, 024513 (2021).
3. “Dynamically Unveiling Metal-Nitrogen Coordination during Thermal Activation to Design High-Efficient Atomically Dispersed CoN4 Active
Sites”, Y. He, Q. Shi, W. Shan, X. Li, A. J. Kropf, E. C. Wegener, J. Wright, S. Karakalos, D. Su, D. A. Cullen, G. Wang, D. J. Myers, and G.
Wu, Angew. Chem. Int. Ed. 60, 9516-9526 (2021).
4. “Detection Technologies for Reactive Oxygen Species: Fluorescence and Electrochemical Methods and Their Applications;” S.
Duanghathaipornsuk, E. J. Farrell, A. C. Alba-Rubio, P. Zelenay; D.-S. Kim, Biosensors, 11, 30 (2021).
5. “Comment on ‘‘Non-PGM electrocatalysts for PEM fuel cells: effect of fluorination on the activity and stability of a highly active NC_Ar + NH3
catalyst’’ by Gaixia Zhang, Xiaohua Yang, Marc Dubois, Michael Herraiz, Régis Chenitz, Michel Lefèvre, Mohamed Cherif, François Vidal,
Vassili P. Glibin, Shuhui Sun and Jean-Pol Dodelet, Energy Environ. Sci., 2019, 12, 3015–3037, 10.1039/C9EE00867E;” X. Yin, E. F. Holby,
and P. Zelenay, Energy Environ. Sci., 14, 1029-1033 (2021).
6. “Performance enhancement and degradation mechanism identification of a single-atom Co–N–C catalyst for proton exchange membrane
fuel cells,” X. Xie, C. He, B. Li, Y. He, D. A. Cullen, E. C. Wegener, A. J. Kropf, U. Martinez, Y, Cheng, M. H. Engelhard, M. E. Bowden, M.
Song, T. Lemmon, X. S. Li, Z. Nie, J. Liu, D. J. Myers, P. Zelenay, G. Wang, G. Wu, V. Ramani, and Y. Shao, Nat. Catal., 3, 1044-1054
(2020).
7. “Acid Stability and Demetalation of PGM-free ORR Electrocatalyst Structures from Density Functional Theory: A Model for “Single-Atom
Catalyst” Dissolution;” E. F. Holby, G. Wang, and P. Zelenay, ACS Catal., 10, 14527-14539 (2020).
8. “Recent Progress in the Durability of Fe-N-C Oxygen Reduction Electrocatalysts for Polymer Electrolyte Fuel Cells;” J. C. Weiss, H. Zhang,
P. Zelenay, J. Electroanal. Chem., 875, 114696 (2020).
9. “Single Cobalt Sites Dispersed in Hierarchically Porous Nanofiber Networks for Durable and High-Power PGM-Free Cathodes in Fuel Cells;”
Y. He, H. Guo, S. Hwang, X. Yang, Z. He, J. Braaten, S. Karakalos, W. Shan, M. Wang, H. Zhou, Z. Feng, K. L. More, G. Wang, D. Su, D. A.
Cullen, L. Fei, S. Litster, and G. Wu. Adv. Mater., 32, 202003577 (2020).

Publications II (since 2020 AMR presentation submission)
10. “On the Lack of Correlation between the Voltammetric Redox Couple and ORR Activity of Fe-N-C Catalysts;” M. C. Elvington, H. T. Chung, L.
Lin, X Yin, P. Ganesan, P. Zelenay, and H. R. Colón-Mercado, J. Electrochem. Soc., 167, 134510 (2020).
11. “Effect of Dispersion Medium Composition and Ionomer Concentration on the Microstructure and Rheology of Fe–N–C Platinum Group
Metal-Free Catalyst Inks for Polymer Electrolyte Membrane Fuel Cells,” Sunilkumar Khandavalli, Radhika Iyer, Jae Hyung Park, Deborah J.
Myers, K. C. Neyerlin, Michael Ulsh, and Scott A. Mauger, Langmuir, 36, 12247-12260 (2020).
12. “Novel platinum group metal-free catalyst ink deposition system for combinatorial polymer electrolyte fuel cell performance evaluation;” J.
Park and D. Myers, J. Power Sources, 480, 228801 (2020).
13. “Status and Challenges for the Application of Platinum Group Metal-Free Catalysts in Proton Exchange Membrane Fuel Cells;” L. Osmieri, J.
Park, D. A. Cullen, P. Zelenay, D. J. Myers, K. C. Neyerlin, Curr. Opin. Electrochem., 25,100627 (2020).
14. “Coupling High-Throughput Experiments and Regression Algorithms to Optimize PGM-Free ORR Electrocatalyst Synthesis;” M. Karim, M.
Ferrandon, S. Medina, E. Sture, N. Kariuki, D.J. Myers, E.F. Holby, P. Zelenay, and T. Ahmed, ACS Appl. Energy Mater., 3, 9083-9088
(2020).
15. “Single-Iron Site Catalysts with Self-Assembled Dual-size Architecture and Hierarchical Porosity for Proton-Exchange Membrane Fuel Cells;”
X. Zhao, X. Yang, M. Wang, S. Hwang, S. Karakalos, M. Chen, Z. Qiao, L. Wang, B. Liu, Q. Ma, D. A. Cullen, D. Su, H. Yang, H. Y. Zang, Z.
Feng, and G. Wu, Appl. Catal. B: Environ., 279, 119400 (2020).
16. “Durability evaluation of a Fe-N-C catalyst in polymer electrolyte fuel cell environment via accelerated stress tests;” L. Osmieri, D. A. Cullen,
H. T. Chung, R. K. Ahluwalia, K. C. Neyerlin, Nano Energy, 78, 105209-105218 (2020).
17. “P-block single-metal-site tin/nitrogen-doped carbon fuel cell cathode catalyst for oxygen reduction reaction;” F. Luo, A. Roy, L. Silvioli, D. A.
Cullen, A. Zitolo, M. T. Sougrati, I. C. Oguz, T. Mineva, D. Teschner, S. Wagner, J. Wen, F. Dionigi, U. I. Kramm, J. Rossmeisl, F. Jaouen, and
P. Strasser, Nat. Mater., 19, 1215-1223 (2020).
18. “Understanding water management in platinum group metal-free electrodes using neutron imaging;” S. Komini Babu, D. Spernjak, R.
Mukundan, D.S. Hussey, D. L. Jacobson, H. T. Chung, G. Wu, A. J. Steinbach, S. Litster, R. L. Borup, and P. Zelenay, J. Power Sources,
472, 228442 (2020).

Publications III and Awards (since 2020 AMR presentation submission)
19. “Utilizing ink composition to tune bulk-electrode gas transport, performance, and operational robustness for a Fe–N–C catalyst in polymer
electrolyte fuel cell;” L. Osmieri, G. Wang, F.C. Cetinbas, S. Khandavalli, J. Park, S. Medina, S.A. Mauger, M. Ulsh, S. Pylypenko, D.J.
Myers, K.C. Neyerlin, Nano Energy, 75, 104943-104955 (2020).
20. “Improving the bulk gas transport of Fe-N-C platinum group metal-free nanofiber electrodes via electrospinning for fuel cell applications;” S.
Kabir, S. Medina, G. Wang, G. Bender, S. Pylypenko, K.C. Neyerlin, Nano Energy, 73, 104791-104802 (2020).
21. “Experimental analysis of recoverable performance loss induced by platinum oxide formation at the polymer electrolyte membrane fuel cell
cathode;” M. Zago*, A. Baricci, A. Bisello, T. Jahnke, H. Yu, R. Maric, P. Zelenay, A. Casalegno, J. Power Sources, 455, 227990 (2020).
22. “X-ray photoelectron spectroscopy and rotating disk electrode measurements of smooth sputtered Fe-N-C films;” Y. Xu, M.J. Dzara, S. Kabir,
S. Pylypenko, K. Neyerlin, A. Zakutayev, Appl. Surf. Sci., 515, 146012-146018 (2020).
Awards
1. Piotr Zelenay, Fellowship of the International Society of Electrochemistry (ISE), Lausanne, Switzerland, April 2021.
2. Luigi Osmieri, Hydrogen and Fuel Cell Technologies Office’s Postdoctoral Recognition Award (Runner Up), Washington, DC, October 2020.
3. David Cullen, Deborah Myers, K.C. Neyerlin, Piotr Zelenay, DOE Hydrogen and Fuel Cells Program Special Recognition Award
for Fuel Cell R&D, Washington, DC, October 2020.

DOE Hydrogen Program.pdf

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