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Andrew Cai_Chemical Expansivity in Ceramic Oxygen Transport Materials_MS Thesis.pdf (10.99 MB)
ETD Abstract Container
Abstract Header
CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS
Author Info
Cai, Andrew
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=case159439738367673
Abstract Details
Year and Degree
2020, Master of Sciences, Case Western Reserve University, Materials Science and Engineering.
Abstract
Chemical expansion of eight lanthanum strontium ferrite (LSF)-based oxygen transport materials (four purchased, four synthesized) was assessed isothermally at 800 °C, 900 °C, and 1,000 °C at oxygen potentials from 10
-0.678
atm (air) to 10
-20.3
–10
-15.9
atm (depending on temperature). The following compositions were tested: (La
0.60
Sr
0.40
)
0.995
Co
0.20
Fe
0.80
O
3-δ
, (La
0.80
Sr
0.20
)
0.95
FeO
3-δ
, (La
0.20
Sr
0.80
) Cr
0.20
Fe
0.80
O
3-δ
, (La
0.20
Sr
0.80
) Co
0.10
Cr
0.20
Fe
0.70
O
3-δ
, (La
0.50
Sr
0.50
)Cr
0.20
Fe
0.80
O
3-δ
, (La
0.20
Sr
0.80
) Co
0.10
Cr
0.10
Fe
0.80
O
3-δ
, (La
0.20
Sr
0.80
)Co
0.10
Cr
0.10
Mg
0.05
Fe
0.75
O
3-δ
, and (La
0.50
Sr
0.50
) Cr
0.20
Mg
0.05
Fe
0.75
O
3-δ
. Powder synthesis utilized aqueous nitrate solutions with malic acid added as a complexing agent. These exhibited good agreement with their target compositions. All eight materials sintered to ≥95% density in 16 hours at 1250–1350 °C. At the lowest partial pressure of oxygen (10
-20.3
, 10
-17.9
, 10
-15.9
) at their respective isothermal temperatures (800 °C, 900 °C, 1000 °C), three compositions demonstrated the lowest chemical expansion: (La
0.60
Sr
0.40
)
0.995
Co
0.20
Fe
0.80
O
3-δ
, (La
0.20
Sr
0.80
) Cr
0.20
Fe
0.80
O
3-δ
, and (La
0.20
Sr
0.80
)Co
0.10
Cr
0.10
Mg
0.05
Fe
0.75
O
3-δ
. Among these materials, (La
0.60
Sr
0.40
)
0.995
Co
0.20
Fe
0.80
O
3-δ
had a higher coefficient of chemical expansion compared to (La
0.20
Sr
0.80
) Cr
0.20
Fe
0.80
O
3-δ
, which is attributed to chromium being less reducible and therefore causing less lattice distortion compared to cobalt. It was concluded that (La
0.60
Sr
0.40
)
0.995
Co
0.20
Fe
0.80
O
3-δ
had low chemical expansion due to the A-site deficiency, and both (La
0.20
Sr
0.80
) Cr
0.20
Fe
0.80
O
3-δ
and (La
0.20
Sr
0.80
)Co
0.10
Cr
0.10
Mg
0.05
Fe
0.75
O
3-δ
due to their less reducible chromium and magnesium content.
Committee
Mark De Guire, Professor (Advisor)
Alp Sehirlioglu, Professor (Committee Member)
Peter Lagerlöf, Professor (Committee Member)
Hoda Hamedani , Doctor (Committee Member)
Pages
134 p.
Subject Headings
Engineering
;
Materials Science
Keywords
Oxygen transport membranes
;
perovskite
;
reduce
;
chemical strain
;
chemical expansion
;
mixed electronic ionic conducting
;
ceramic
;
methane reforming
;
syngas
Recommended Citations
Refworks
EndNote
RIS
Mendeley
Citations
Cai, A. (2020).
CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS
[Master's thesis, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case159439738367673
APA Style (7th edition)
Cai, Andrew.
CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS.
2020. Case Western Reserve University, Master's thesis.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=case159439738367673.
MLA Style (8th edition)
Cai, Andrew. "CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS." Master's thesis, Case Western Reserve University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case159439738367673
Chicago Manual of Style (17th edition)
Abstract Footer
Document number:
case159439738367673
Download Count:
320
Copyright Info
© 2020, some rights reserved.
CHEMICAL EXPANSIVITY IN CERAMIC OXYGEN TRANSPORT MATERIALS by Andrew Cai is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.