Upload
zixuan-wang
View
360
Download
0
Embed Size (px)
Citation preview
Validation of High Throughput Electrochemical Gas Sensing
Screening System
Zixuan WangNovember 17, 2014
Background
Harsh combustion environment - 800 °CAccurate and selective to target gas
High Throughput Methodology
Subatomic difference affect large scale
Not feasible to individually test material
High throughput synthesis and characterization methods
High Throughput Methodology
• Normalize affect of distance on the potential
Development of Uniform Standard Sample
Single Cell
Surface Mechanisms
Sensors and Actuators B 121 (2007) 652-663
NO N2O2- O2
O2-O2-
e-
Reflectometry Results - YSZ
• Results confirm relative uniformity of sample (1.8% difference)
XRD Results - YSZ
• XRD analysis using Jade• YSZ Cubic:
– (111): 29.675°– (200): 34.398°
• Confirm identical phases
(1,4) 29.745
(2,4) 29.836 34.848
(3,4) 29.876 34.859
25 27 29 31 33 35 37 39 41 43 450
200
400
600
800
1000
1200
1400
1600
YSZ Post Anneal XRD Uniformity
(1,4)(2,4)(3,4)
Reflectometry Results – WO3
• Confirms relative uniformity (2.5% difference)
• Evidence some parts of the plate that are slightly thicker or thinner
XRD Results – Post Annealed WO3
• XRD analysis using Jade• WO3 monoclinic:
– (002): 23.118°– (020): 23.582°– (200): 24.365°
• Confirm identical phases with phase shifts present
22.5 23 23.5 24 24.5 250
500
1000
1500
2000
2500
3000
3500
4000
WO3 Post Anneal XRD Uniformity
(1,4)(2,4)(3,4)
2θ
Inte
nsity
(1,4) 23.143 23.653 24.362
(2,4) 23.140 23.671 24.397
(3,4) 23.127 23.641 24.377
Reflectometry Results - WO3-YSZ
• Sputtering conditions: same
• YSZ held constant• Confirms relative
uniformity (4.3% difference)
XRD Results – WO3-YSZ Post-annealed
W M(000) WO3 monoclinic: (002): 23.118°(020): 23.582°(200): 24.365°YSZ Cubic: (111): 29.675°(200): 34.398°
W M(020)
W M(200)
Y C(200)
Electrochemical Cell Setup30
electrode probes
Gas inlet
Sample stage
Single Electrochemical Cell Tests
1 10 19 28 37 46 55 64 73 82 91 100 109 118 127 136 145 154 163 172 181 190 199 208 217140
160
180
200
220
240
260 EMF Response of WO3/YSZ/Pt Cell at 600 C
Time (min)
Pote
ntial
(mV)
481
ppm
NO
926
ppm
NO
2083
ppm
N
O 481
ppm
NO
926
ppm
N
O 2083
ppm
N
O
2083
ppm
NO
Electrochemical Cell Tests
400 600 800 1000 1200 1400 1600 1800 2000 2200150160170180
0102030
Sensor Response
Potential Linear (Potential)Change in Potential Linear (Change in Potential)Linear (Change in Potential)
NO Concentration (ppm)
Pote
ntial
(mV)
Chan
ge in
Pot
entia
l (Δm
V)
Multielectrode Cell Tests
0 10 20 30 40 500
20
40
60
80
100
120
140
160
180
200
EMF Response of WO3/YSZ/Pt Cell at 600 C
Time (min)
Resp
onse
(mV)
164
ppm
NO
246
ppm
NO
328
ppm
NO
Conclusions• Designed planar sensor array– Use for combinatorial screening of electrochemical
gas sensors• Confirm deposition uniformity– Reflectometry: thickness– XRD: phases
• Cell potential – Changes valid use of planar sensor design
Future Work
• Create multielectrode with increased surface area/perimeter of the electrodes
• Normalize potential to distance of electrodes• Create multielectrode with different
composition gradient
Acknowledgements
• National Science Foundation (NSF)• University of South Carolina – College of
Engineering and Computing• Strategic Approaches to the Generation of
Electricity (SAGE)• Principal investigators: Dr. Jochen Lauterbach and
Dr. Jason Hattrick-Simpers• Graduate mentor: Ben Ruiz-Yi