Bimetallic Au–Pd nanoparticles dispersed on a nanohybrid three-dimensionally ordered macroporous (3DOM) perovskite support exhibit a synergy for catalytic methane oxidation. The large support surface area, high Au–Pd dispersion, strong noble metal–support interaction, and an enrichment of adsorbed oxygen species (invoked by the Au inclusion) combine to boost catalytic performance. Visit our website, http://www.pcrg.unsw.edu.au , for the latest news, publications, and research from our group.

1. ACS Catal. 2016, 6 (10), pp 6935-6947
DOI: 10.1021/acscatal.6b01685
High Performance Au−Pd Supported on 3D Hybrid Strontium-
Substituted Lanthanum Manganite Perovskite Catalyst for Methane
Combustion
Yuan Wang†, Hamidreza Arandiyan*†, Jason Scott*†, Mandana Akia‡, Hongxing Dai*§, Jiguang Deng§, Kondo-
Francois Aguey-Zinsou⊥, and Rose Amal†
† Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
⊥MERLin Group, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
‡Mechanical Engineering Department, University of Texas-Rio Grande Valley, 1201 West University Drive, Edinburg, Texas 78539, United States
§Beijing Key Laboratory for Green Catalysis and Separation, and Laboratory of Catalysis Chemistry and Nanoscience, Beijing University of Technology, Beijing
100124, China
Key Contact
Scientia Prof. Rose Amal
School of Chemical Engineering
University of New South Wales
Tel: +61 2 93854361
Email: r.amal@unsw.edu.au

2.  Low Emission
 Abundant Source
 Environmental Friendly
CO2 Emissions from Fossil
Energy Sources
• NGVA Europe, https://www.ngva.eu/
• BP statistics, http://www.bp.com/content/dam/bp/pdf/energy-economics/statistical-review-2015/bp-statistical-review-of-world-energy-2015-full-report.pdf
• Natural gas, https://www.wintershall.com/crude-oil-natural-gas/natural-gas.html
Introduction

3. PVA
NaPdCl4
HAuCl4 3DOM LSMO
(1)
Stir
Step 1: Mixing the HAuCl4,
PdCl2, PVA solution and LSMO
catalyst and stirring for 20min.
Step 2: Replacing stir system to
N2 gas bubble system and adding
NaBH4 solution under the ice
bath.
Step 3: After bubble treatment for
8h and standing for overnight, the
wet solid catalyst was filtered and
washed by distilled water and
ethanol to remove the Cl- ions.
Step 4: Drying at 100°C in oven
for 12h and calcining at ramp
1°C/min to 450ºC and keeping
for 3h.
√ Clear water:
Bubble treatment for 8h
and standing for
overnight.
×Yellow water:
Bubble treatment for
6h. There are noble
metal particles in the
water.
(3)
Distilled water
Ethanol
Vacuum
(4)
Tube furnace
NaBH4
(2)
N2
3DOM LSMO
Au, Pd NPs
Ice bath
Synthesis Strategy—Au-Pd/3DOM LSMO
Synthesis process of zAuxPdy /3DOM LSMO (z=1, 2 and 3 wt%, molar ratio Au/Pd: x:y=1:2) samples

4. HRSEM and 3D-eAFM images of PMMA, 3DOM LSMO, noble metal supported 3DOM LSMO and 1DDN LSMO
(b) PMMA hard template
100 nm
(j) 1Au/3DOM LSMO
2 μm
(c) 1AuPd/1DDN LSMO
(g) 1AuPd/3DOM LSMO
400 nm
2 μm
(d) 3DOM LSMO
400 nm
(e) 3DOM LSMO
400 nm
(k) 1Pd/3DOM LSMO
2 μm
(i) 1Au/3DOM LSMO
100 nm
(h) 1AuPd/3DOM LSMO
100 nm
(f) 3DOM LSMO
100 nm
(l) 1Pd/3DOM LSMO
400 nm
(a) PMMA hard template

5. 20 nm
(f) 3AuPd/3DOM LSMO
50 nm
(h) 1Pd/3DOM LSMO
50 nm
(a) 1AuPd/3DOM LSMO
50 nm
(d) 2AuPd/3DOM LSMO
50 nm
(k) 1Au/3DOM LSMO
2 nm
(c) 1AuPd/3DOM LSMO
(e) 2AuPd/3DOM LSMO
2 nm
0.216 nm
2 nm
(g) 3AuPd/3DOM LSMO
0.215 nm
2 nm
(j) 1Pd/3DOM LSMO
2 nm
(l) 1Au/3DOM LSMO
0.223 nm
1 2 3 4 5
0
10
20
30
Frequency(%)
Nanoparticle Size (nm)
10 nm
(i) 1Pd/3DOM LSMO
1 2 3 4 5
0
5
10
15
20
25
Frequency(%)
Nanoparticle Size (nm)
10 nm
(b) 1AuPd/3DOM LSMO
1 2 3 4 5
0
10
20
30
40
Frequency(%)
Nanoparticle Size (nm)
d= 2.15 nm
d= 2.25 nm
d= 2.35 nm

6. (c)
(f)(d)
Pd
(e)
Au
(a)
Pd
(b)
Au Pd+Au
HAADF-STEM images and EDS elemental maps for 1AuPd/3DOM LSMO sample of (a-c) EDS elemental maps of Pd, Au and
combined of Au+Pd, (d, e) 3D visualization of Pd and Au and (f) EDS intensity line profiles extracted from the spectrum image
along the line drawn on image (c)
Pd and Au atoms are well dispersed on the nanoparticle

7. 28 42 56 70 84
 




(a)
(b)
(c)
(d)
(e)
Intensity(a.u.)
2 Theta (Deg.)
(f)
LSMO perovskite
No. 04-016-6114
Macropore diameter, BET surface areas, crystallite sizes (Dsupport), pore volume, noble metal particle size and real AuPd content of samples.
a Determined by the ICP-AES results; b Calculated based on the XPS results;
Sample
Au contenta
(wt%)
Pd contenta
(wt%)
Noble metal contenta
BET surface area
(m2/g)
Surface element compositionb
Nominal
(wt%)
Measured
(wt%)
Mn4+/Mn3+
molar ratio
Oads/Olatt
molar ratio
Auδ+/Au0
molar ratio
Pd2+/Pd0
molar ratio
3DOM LSMO - - - - 32.4 1.42 1.04 - -
1Au/3DOM LSMO 0.94 - 1 0.94 32.6 1.21 1.16 0.20 -
1Pd/3DOM LSMO - 0.85 1 0.85 32.0 0.91 1.38 - 0.71
1AuPd/3DOM LSMO 0.44 0.48 1 0.92 33.6 1.15 1.21 0.31 0.73
2AuPd/3DOM LSMO 0.95 0.98 2 1.93 33.3 1.03 1.37 0.39 0.85
3AuPd/3DOM LSMO 1.42 1.50 3 2.92 33.8 0.89 1.49 0.42 1.23
1AuPd/1DDN LSMO 0.45 0.50 1 0.95 4.32 1.26 1.09 0.28 0.50
92 90 88 86 84 82 80
1Au/3DOM LSMO
1AuPd/3DOM LSMO
2AuPd/3DOM LSMO
3AuPd/3DOM LSMO
Binding energy (eV)
Intensity(a.u.)
Au 4f
344 342 340 338 336 334 332
Binding energy (eV)
Intensity(a.u.)
Pd 3d
1Pd/3DOM LSMO
1AuPd/3DOM LSMO
2AuPd/3DOM LSMO
3AuPd/3DOM LSMO
𝑨𝒖 𝟎
+ 𝑴𝒏 𝟒+
→ 𝑨𝒖 𝜹+
+ 𝑴𝒏 𝟑+
(1)
𝑷𝒅 𝟎
+ 𝑴𝒏 𝟒+
→ 𝑷𝒅 𝜹+
+ 𝑴𝒏 𝟑+
(2)
XRD and XPS
• XRD profile of (a) 3DOM LSMO, (b) 1Au/3DOM LSMO, (c) 1Pd/3DOM LSMO, (d) 1AuPd/3DOM LSMO,
(e) 2AuPd/3DOM LSMO, (f) 3AuPd/3DOM LSMO.
• Au 4f and Pd 3d XPS spectra of the monometallic and bimetallic Au-Pd supported catalysts.
Shifted 0.3 eV Shifted 0.5 eV

8. 480 600 720 840
0.00
0.01
0.02
0.03
0.04
0.05
680
860
665
1DDN LSMO
3DOM LSMO
Intensity(a.u.)
Temperature (°C)
Brønsted acid sites
Weak acid sites
110 220 330 440 550 660 770
Intensity(a.u.)
Temperature (°C)
peakpeak
250 620
125
542
162
608
643200
160
660
305 640
380310 650
(g)
(a)
(b)
(c)
(d)
(e)
(f)
• H2-TPR profiles of (a) 3DOM LSMO, (b) 1Au/3DOM LSMO, (c) 1Pd/3DOM LSMO, (d) 1AuPd/3DOM LSMO, (e)
2AuPd/3DOM LSMO, (f) 3AuPd/3DOM LSMO and (g) 1AuPd/1DDN LSMO.
• NH3-TPD profiles of 1DDN LSMO and 3DOM LSMO samples.
H2-TPR and NH3-TPD
La3+ and Sr2+ are non-reducible under the H2-TPR conditions
2
III IV III
1 1 3 2 1 23
1 1
La Sr Mn Mn O H La Sr Mn O H O
2 2
xx x x x x xx x     
21 2 2 3 23
1 1 1
La Sr MnO H (1 )La O MnO SrO H O
2 2 2
xx x x x       
α-peak:
β-peak:
Rich Brønsted acid sites and weak acid sites (Lewis
acid sites) on the surface of 3DOM structure
The rich Brønsted acid sites were reported to
have remarkable synergistic effect with the
supported Pd and Pt NPs, helping to adsorb and
activate reactant molecules during the catalytic
process, Scientific Reports, 3 (2013), 2349.

9. Methane conversion versus reaction temperature of (a) 1Au/3DOM LSMO, (b) 1Pd/3DOM LSMO, (c) physical mixture of
1Pd/3DOM LSMO and 1Au/3DOM LSMO, (d) 1AuPd/3DOM LSMO and (B) Dependence of methane conversion at 350 °C
and ratio of Oads/Olatt, Pd2+/Pd0 and Auδ+/Au0.
Catalytic Activity
Sample
Methane conversion (°C)
T10% T50% T90%
3DOM LSMO 344 384 508
1Au/3DOM LSMO 338 375 402
1Pd/3DOM LSMO 323 358 378
1Au+1Pd/3DOM LSMO 340 360 405
1AuPd/3DOM LSMO 304 350 382
2AuPd/3DOM LSMO 280 331 354
3AuPd/3DOM LSMO 265 314 336
1AuPd/1DDN LSMO 322 370 400
200 300 400 500 600
0
50
100
0
50
100
0
50
100
0
50
100
(d)
(c)
(a)
(b)
Methaneconversion(%)
Temperature (°C)
(A) Au atom
Pd atom
+
Au atom
Pd atom
Pd atom
Au atom
3DOM LSMO3DOM LSMO
3DOM LSMO
3DOM LSMO
3DOM LSMO
T50%=350°C
Methane Combustion
Table. Catalytic activites of the 3DOM, AuPd/3DOM LSMO,
AuPd/1DDN LSMO samples.
Mixture
Furnace
GC
Micro-TCD
Mass Flow Controller

10. 15.6 16.8 18.0
0.0
0.2
0.4
0.6
0.8
TOFcat
(×10
-3
s
-1
)
H2
consumption (mmol/gcat)
1AuPd/3DOM LSMO
1Pd/3DOM LSMO
3AuPd/3DOM LSMO
2AuPd/3DOM LSMO
1AuPd/3DOM LSMO
3DOM LSMO
3DOM LSMO
Au atom
Pd atom
3DOM LSMO
Pd atom
3DOM LSMO
Au atom
Good catalytic performance for bimetallic Au-Pd/3DOM LSMO is due to the combination of many aspects:
1. Good low-temperature reducibility;
2. High surface areas and internal surface;
3. Rich Brønsted acid sites;
4. High concentration of surface adsorbed oxygen species;
5. More active phase (Pd2+ and Auδ+) with synergistic effect;
• Dependence of methane conversion at 350 °C and ratio of Oads/Olatt, Pd2+/Pd0 and Auδ+/Au0
• Correlation of the TOF at 270 °C and the H2 consumption over the obtained samples
3DOM LSMO
1Au/3DOM LSMO
1Pd/3DOM LSMO
1AuPd/3DOM LSMO
2AuPd/3DOM LSMO
3AuPd/3DOM LSMO
1AuPd/1DDN LSMO
0
20
40
60
80
100
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Methaneconversion(%)
Ratioofsurfacespecies
Activity
at 350°C
Pd
2+
/Pd
0
Au
&+
/Au
0
Oads
/Olatt
Catalytic Performance Evaluation

11. This work can be found in the
ACS Catal. 2016, 6 (10), pp 6935-6947
DOI: 10.1021/acscatal.6b01685
More information on the
Particle Catalysis Research Group at:
http://www.pcrg.unsw.edu.au/
Th A N K SThorium Adamantium Nitrogen Potassium Sulpher
90 124 7 1619
https://www.facebook.com/groups/PARTCATatUNSW
https://twitter.com/PartcatGroup
Journal Cover Page