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Ambient-Pressure NEXAFS and XPS at CSX2 Beamline: Soft X-rays for the In-situ Study of Catalytic Processes
Workshop on First Experiments at NSLS-II, August 2013 [email protected]
Chemistry Dept Sanjaya Senanayake Dario Stacchiola Jingguang Chen (SCC) Jose Rodriguez (SCC)
CFN Peter Sutter Samuel Tenney Anibal Boscoboinik
Photon Sciences Cecilia Sanchez Hanke Dario Arena
Goals Instrumentation: Build and use end-stations for soft X-ray ambient-pressure AP-XPS and AP-NEXAFS at NSLS-II CSX2 beamline: pressure range up to 1 atm.
Catalysis: Study in-situ the water-gas shift (WGS) on (Au,Cu)/CeOx/TiO2
Surface chemistry: Study in-situ the processes of CO2 capture on solid sorbents.
Polarization control: Identify surface species and reaction intermediates taking advantage of the unique polarization-switching capabilities of the CSX2 beamline.
Sci
ence
cas
e
H2O + CO → CO2 + H2
CSX-2 Full polarization control branch
CSX-1 High coherent flux branch
Endstation 1 (Chemistry) AP-NEXAFS Powder catalysts
Endstation 2 (CFN) AP-XPS & AP-NEXAFS on Planar catalysts
CSX2 beamline real-space layout
AP-XPS & AP-NEXAFS at NSLS-II
AP-XPS AP-NEXAFS
model catalysts AP-NEXAFS
powders
Endstation 1 Endstation 2
AP-STM: CeOx/CuO
beam
E-TEM: CeOx/CuO
ALS, ACS Catal. 2 (2012) 2250
ALS, Phys. Chem. Chem. Phys. 13 (2011) 19988
Model catalysts Powder catalysts
AP-XPS Endstations in the U.S.
ALS, 2 End-stations SSRL NSLS
AP-XPS Endstations Worldwide
ALS Beamline 11.0.2: consistently most oversubscribed beamline for time at the ALS - Berkeley Current cycle: Only 9% of requested beamtime allocated
Location Status Log P (Torr)
-12 -10 -8 -6 -4 -2 0 2 4
AP-XPS at NSLS AP-XPS at NSLS-II
UHV Surface Science Industrial Catalysis
Ambient pressure XPS: chemically sensitive spectroscopy at elevated pressures
AP-XPS – Powerful Method with High User Demand
International growth – Opportunity for leading-edge performance at NSLS II
Chem. Soc. Rev., 2013, 42, 5833--5857
AP-XPS at NSLS II CSX2 Beamline
z
hν
Background Gas Pressure = P
e-
Entrance Nozzle to Differentially Pumped
Electrostatic Lens
Sample
d
Towards Ambient Pressure XPS
dNozzle spacing, z Pmax Performance
300 μm 300 μm 5 Torr Current AP-XPS @ ALS, Berkeley
2 μm 2 μm 750 Torr Atmospheric P
Fundamental pressure limit: Elastic & inelastic e- scattering in gas phase.
P ∝ 1d
z ≈ d
Ip = Ivac ⋅exp −zσ E( )P kT( )
Current config.
Plus two focusing mirrors
Pres
sure
(Tor
r)
Temperature (K)
Current AP-XPS
Future AP-XPS
at NSLS-II
Atmospheric and environmental chemistry
Catalysis
200 400 600 800 1000 10-4 10-3 10-2 10-1 10 0 10 1 10 2 10 3 10 4
clean H2
10 x 106 t $ 134 b
Preferential oxidation Methanation 99.99% H2
WGS
99% H2
CO removal Reforming steam dry autothermal Partial oxidation
Electrolysis of water
Energy
4 %
96 %
NG (48%) Oil (30%) Coal (18%) Biomass
Hydro Solar Wind Geo Ocean
Nuclear
Ammonia
Fuel processing
Hydrogenation
Hydrogen Fuel Cells
~ 50%
~ 50%
PRODUCTION USE
Syngas 80% H2 20% CO
CO + H2O ↔ CO2 + H2
Need for clean hydrogen : Water Gas Shift (WGS) Reaction
WGS
HTS (600-750 K): Cr2O3 + Fe3O4 LTS (450-550 K) : Cu/ZnO
AP-XPS for Catalysis & Surface Chemistry
Example I: Water-gas-shift catalysis Stacchiola, Senanayake, Rodriguez, Chem Dept ALS 9.2
AP-XPS for Catalysis & Surface Chemistry
Example I: Water-gas-shift catalysis Stacchiola, Senanayake, Rodriguez, Chem Dept ALS 9.2
CO + H2O CO2 + H2
1.50 1.55 1.60 1.65 1.70 1.75-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
1000 K/T
Ln{r
ate/
(1015
mol
ecul
es c
m-2
s-1
)}
292 287 282BE / eV
CO(g)
C 1s
CO C0
CeOx / Cu(111)
Cu(111)
Angew. Chemie Int. Ed 2013 DOI 10.1002/anie.201210077
Activity of ceria/metal catalysts, andAmbient Pressure XPS under in-situ conditions
CO + H2O ↔ CO2 + H2
WGS
Inverse
Oxi Metal
CeOx / Cu(111)
Binding energy (eV)104106108110112114116118120122124126128
Inte
nsity
(arb
itrar
y un
its)
Ce4d
300K
550K
CeO1.90
CeO1.65
State of catalyst under reaction conditions
Beamline 9.3.2 Zhi Liu
0.5 Torr
Oxide-supported amines
Questions:- Capture mechanism- Influence of support- Effect of ‘poisons’, NOx,SOx
- Capture & release kinetics
Inte
nsity
(a.u
.)
Binding energy (eV)
3AP
Issues:- Energy intensive CO2 removal.- MEA solution corrosive.- NOx/SOx poison solution.
Conventional liquid-phase CO2 capture
CO2(aq) → H2CO3 → HCO3- + AH+H2O MEA
CO2(aq) + MEA → -OOCHNC2H4OH + AH+
AP-XPS on model systems: Amines on TiO2(110)
011
101
AP-XPSC1s
1.90 Å1.93 Å2.27 Å
2.44 Å 1.84 Å
3AP/TiO2(110)
MEA/TiO2(110)
Ti O
N
✓
✗
A = monoetanolamine [MEA] = H2NC2H4OH
Example II: Solid-state CO2 capture S. Tenney, P. Sutter, CFN, NSLS X1A
Issues:- Energy intensive CO2 removal.- MEA solution corrosive.- NOx/SOx poison solution.
Conventional liquid-phase CO2 capture
CO2(aq) → H2CO3 → HCO3- + AH+H2O MEA
CO2(aq) + MEA → -OOCHNC2H4OH + AH+
A = monoetanolamine [MEA] = H2NC2H4OH
AP-NEXAFS at NSLS-II
AP-XPS AP-NEXAFS
model catalysts AP-NEXAFS
powders
Endstation 1 Endstation 2
AP-STM: CeOx/CuO
beam
E-TEM: CeOx/CuO
ALS, ACS Catal. 2 (2012) 2250
ALS, Phys. Chem. Chem. Phys. 13 (2011) 19988
Model catalysts Powder catalysts
Experiments of AP-NEXAFS on model catalysts
Unique tool:
Cross-section and features in the
AP-NEXAFS will change with
polarization of light
AP-NEXAFS at NSLS-II
S. Kaya et al. / Catalysis Today 205 (2013) 101–105 JCP 138, 024704 (2013)
SSRL ALS
AP-NEXAFS at NSLS-II
1 Torr, 700 K
Ambient-Pressure NEXAFS and XPS at CSX Beamline: Soft X-rays for the In-situ Study of Catalytic Processes
Objectives: First light experiments: - In-situ Study of the WGS on (Au,Cu)/CeOx/TiO2 Planar and Powder catalysts - Study the mechanism for capture of CO2 on solids
- We will be testing the linear polarization devices of the beamline Development of instrumentation: -Unique facilities for studying reaction mechanisms at the surface of planar and powder catalysts. These will benefit users at CFN and Synchrotron Catalysis Consortium (SCC)
-The combination of the linearly polarized light with AP-NEXAFS is unique. Will be the first to achieve Atmospheric pressures in AP-XPS
CeOx / TiO2(110)
TiO2
CeOx