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
13
Embed
Ambient-Pressure NEXAFS and XPS at CSX2 Beamline: Soft X ...Ambient-Pressure NEXAFS and XPS at CSX2 Beamline: Soft X-rays for the . In-situ. Study of Catalytic Processes . Workshop
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
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]
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.
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