About

Lisa Anderson is a Clinical Assistant Professor at The Grainger College of Engineering at the University of Illinois Urbana-Champaign. She is associated with the Illinois Leadership in Engineering Education (ILEE). Her contact email is lja@illinois.edu. The page does not provide specific details about her research focus, background, or key contributions.

Research topics

• Physical chemistry
• Chemistry
• Materials science
• Chemical engineering
• Composite material
• Metallurgy
• Organic chemistry
• Crystallography
• Inorganic chemistry
• Thermodynamics

Selected publications

• Low Redox Chemical Expansivity in Orthorhombic Perovskites La _0.8 Ca _0.2 FeO _3-δ and Y _0.8 Ca _0.2 FeO _3-δ : Relationship to Charge Distribution and Bond Angles

  Chemistry of Materials · 2026-03-31

  article1st author

  Chemo-mechanical coupling is an important consideration for the stable operation of mixed ionic/electronic conductors. Redox strains should be minimized while maintaining high redox activity. Past work demonstrated the benefits of locating redox on O rather than on cations to lower chemical expansivities, but covalency may be preferable for conductivity and redox activity. Here, we investigate how B–O bond charge distribution in ABO3 perovskites relates to redox coefficients of chemical expansion (CCEs) and the underlying composition and structure. Y0.8Ca0.2FeO3 (YCF) and La0.8Ca0.2FeO3 (LCF) were prepared as comparators with identical orthorhombic space groups, A-site electronegativities, and B-site cations but different A-site radii, B–O–B bond angles, and bond lengths, confirmed by synchrotron XRD. Isothermal redox strains and corresponding oxygen stoichiometry changes were evaluated by dilatometry and thermogravimetric analysis, respectively, during steps in oxygen partial pressure (6 pO2 points between 10–4 and 1 atm; 4 isotherms between 600 and 750 °C). O K-edge and Fe L-edge synchrotron XAS were measured for reduced and oxidized samples of each composition to evaluate the degree of hybridization and location of redox. While it was expected that higher B–O–B angles would be associated with greater hybridization, the opposite relationship was found and attributed to the polarizability difference of the A-site cations. YCF exhibited lower Fe–O–Fe angles, greater Fe–O hybridization, and lower redox CCEs (0.010–0.014 vs 0.016–0.020 for LCF). Conductivity activation energy analysis proved to be consistent with large-polaron hopping (partial charge localization) and the hybridization observed by XAS. This work demonstrates that distorted, partially covalent perovskites can exhibit low redox CCEs to improve structural stability in electrochemical devices.

  PublisherDOI

• Tuning Perovskites’ Hydration-Induced Chemical Expansion with Octahedral Tilt Angles

  Chemistry of Materials · 2024-06-04 · 5 citations

  articleOpen access1st author

  Hydration-induced strains in proton-conducting oxides compromise chemo-mechanical stability when these materials are applied in protonic ceramic electrochemical cells. To develop design principles for zero-strain materials, we systematically studied the hydration coefficients of chemical expansion (CCEs) in perovskite (Sr, Ba)(Ce, Zr, Y)O3–x solid solutions with in situ dilatometry and thermogravimetric analysis in the range of 430–630 °C. By including and decoupling a wide range of tolerance factors and lattice parameters, we were able to identify a minimum in hydration CCEs (0–0.02) at intermediate tolerance factor values (t ≈ 0.95). Conversely, despite expectations of lower CCEs in larger unit cells, no general trend in CCE versus lattice parameter was found, and opposite trends could be seen for Sr(Ce, Zr, Y)O3–x versus Ba(Ce, Zr, Y)O3–x separately. In situ neutron diffraction (ND) enabled atomistic insight. Upon decreasing t, chemical strain anisotropy increased, but this trend did not match the U-shaped dependence of macroscopic CCEs on t. Instead, perovskites with intermediate t, hosting intermediate octahedral tilt angles in the nominally dry state, underwent the largest change in the B–O–B angles during hydration. Accommodating hydration through decreasing B–O–B angles is beneficial because it does not result in large lattice parameter changes. We propose an intermediate tolerance factor as a simple structural descriptor to enable near-zero hydration strains in proton-conducting perovskites.

  PublisherOA PDFDOI

• Effects of state filling and localization on chemical expansion in praseodymium-oxide perovskites

  Journal of Materials Chemistry A · 2023-01-01 · 13 citations

  article

  Computational study of Pr-based perovskites supported by experiments uncovering insights and design principles for chemical expansion. Hole location on oxygen is highlighted as a route to achieving near-zero chemical expansion.

  PublisherDOI

• Indispensable Nafion Ionomer for High-Efficiency and Stable Oxygen Evolution Reaction in Alkaline Media

  ACS Applied Materials & Interfaces · 2023 · 27 citations

  • Materials science
  • Chemical engineering
  • Inorganic chemistry

  Addressing the challenge of sluggish kinetics and limited stability in alkaline oxygen evolution reactions, recent exploration of novel electrochemical catalysts offers improved prospects. To expedite the assessment of these catalysts, a half-cell rotating disk electrode is often favored for its simplicity. However, the actual catalyst performance strongly depends on the fabricated catalyst layers, which encounter mass transport overpotentials. We systematically investigate the role and sequence of electrode drop-casting methods onto a glassy carbon electrode regarding the efficiency of the oxygen evolution reaction. The catalyst layer without Nafion experiences nearly 50% activity loss post stability test, while those with Nafion exhibit less than 5% activity loss. Additionally, the sequence of application of the catalyst and Nafion also shows a significant effect on catalyst stability. The catalyst activity increases by roughly 20% after the stability test when the catalyst layer is coated first with an ionomer layer, followed by drop-casting the catalysts. Based on the half-cell results, the Nafion ionomer not only acts as a binder in the catalyst layer but also enhances the interfacial interaction between the catalyst and electrolyte, promoting performance and stability. This study provides new insights into the efficient and accurate evaluation of electrocatalyst performance and stability as well as the role of Nafion ionomer in the catalyst layer.

  PublisherDOI

• Correction to Toward Zero-Strain Mixed Conductors: Anomalously Low Redox Coefficients of Chemical Expansion in Praseodymium-Oxide Perovskites

  Chemistry of Materials · 2022-03-21

  article1st authorCorresponding

  ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to Toward Zero-Strain Mixed Conductors: Anomalously Low Redox Coefficients of Chemical Expansion in Praseodymium-Oxide PerovskitesLawrence O. AndersonLawrence O. AndersonMore by Lawrence O. Andersonhttps://orcid.org/0000-0003-0216-6170, Adrian Xiao Bin YongAdrian Xiao Bin YongMore by Adrian Xiao Bin Yonghttps://orcid.org/0000-0002-0691-2380, Elif ErtekinElif ErtekinMore by Elif Ertekinhttps://orcid.org/0000-0002-7816-1803, and Nicola H. Perry*Nicola H. PerryMore by Nicola H. Perryhttps://orcid.org/0000-0002-7207-2113Cite this: Chem. Mater. 2022, 34, 7, 3537Publication Date (Web):March 21, 2022Publication History Published online21 March 2022Published inissue 12 April 2022https://doi.org/10.1021/acs.chemmater.2c00701Copyright © 2022 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views393Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (608 KB) Get e-Alerts Get e-Alerts

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• Modifying Crystal Symmetry and B-O Charge Distribution to Tailor Chemical Expansion in Mixed Conducting Perovskites

  ECS Meeting Abstracts · 2022-07-07

  article1st authorCorresponding

  The exchange of ions between a lattice and the gaseous phase makes mixed conducting oxides ideal for a range of electrochemical applications. Altering oxygen ion concentration is accompanied by a change to electronic species concentrations, and this influences electrical, chemical, kinetic, and mechanical properties. The stability of electrochemical devices like fuel cells and batteries can heavily rely on the mechanical response to changes in chemical defect concentrations. Under both dynamic and steady-state operation of these devices, large volume strains and strain mismatch at interfaces can result in fracture, warping, and delamination that can cause performance degradation and/or failure. Strains between different materials are compared using the coefficient of chemical expansion (CCE), which normalizes the isothermal chemical strain by the change in defect concentration. Here, we advance the understanding of chemo-mechanical coupling through the study of PrGa 0.9 Mg 0.1 O 3-δ and BaPr 0.9 Y 0.1 O 3-δ by demonstrating CCEs 2-5x lower than any previously reported perovskite oxide 1 . Isothermal CCEs were evaluated with in situ, high temperature, and variable atmosphere x-ray diffraction and dilatometry for chemical strains, and with thermogravimetric analysis for stoichiometry changes. The experimental results show chemical strains to be significantly lower than predictions from simple empirical models that assume pseudo-cubic structures and full charge localization on multivalent cations, like Pr. To evaluate actual charge distribution, in situ impedance spectroscopy and density functional theory calculations were performed. The collaboration of experimental and computational work combines accurate and reliable material characterization with insights into atomic and electronic structures that are difficult to probe experimentally. Our results for the studied compositions indicate 2 primary factors that can be used to modify CCEs: 1) Altering the crystal structure away from the isotropic, cubic phase encourages anistropic expansion and lower CCEs in polycrystalline materials, and 2) Varying the distribution of charge along B-O bonds is shown to dramatically alter the CCE. While the first factor provides rather clear guidance to tailor expansion, we elaborate on the second by suggesting band structure design principles for near-zero redox-strain perovskites, and the benefit of locating holes partially or fully on oxygen is highlighted. These new findings add to the growing collection of crystal-chemical design rules for the rational tailoring of chemo-mechanical coupling in perovskite oxides. (1) Anderson, L. O.; Yong, A. X. Bin; Ertekin, E.; Perry, N. H. Toward Zero-Strain Mixed Conductors: Anomalously Low Redox Coefficients of Chemical Expansion in Praseodymium-Oxide Perovskites. Chem. Mater. 2021 , 33 (21), 8378–8393. https://doi.org/10.1021/ACS.CHEMMATER.1C02739.

  PublisherDOI

• Understanding Chemical Expansion in Pr-Based Mixed Conducting Perovskites PrGa_0.9Mg_0.1O₃ and BaPr_0.9Y_0.1O₃

  ECS Meeting Abstracts · 2021-05-30

  article1st authorCorresponding

  Chemical expansion is a strain induced by a change in stoichiometry, such as oxygen loss, and it can have a significant impact on device performance and lifetime. While large coefficients of chemical expansion (CCE) are needed for high displacements in an actuator, the same, large CCE can be deleterious to device longevity in a fuel cell where large chemical potential gradients exist across very small thicknesses. The breadth of CCE values needed in various devices calls for the development of design rules to tailor CCE for optimal material response, so our work targets the establishment of such structure-property insights. Oxygen-loss-induced, stoichiometric chemical expansion in oxides involves the formation of an oxygen vacancy; when oxygen leaves the lattice, charge compensating electrons are left behind and can localize on nearby multivalent cations. As cations are reduced, their atomic radii and the surrounding lattice expand. An empirical formula describing the pseudo-cubic lattice constant of perovskite materials has been developed [1] which relates the lattice parameter to the ionic radii of cation and anion components. This equation predicts that changes in the B-site cation size will have a larger effect on the lattice parameter than an equal change at the A-site. If the multivalent cation is the only one changing size during redox processes, this equation suggests that its placement on the A or B site will have a significant effect on the magnitude of the overall lattice strain during oxygen loss or gain. In an effort to develop and understand design rules to tailor CCE, two compositions, PrGa 0.9 Mg 0.1 O 3 (PGM) and BaPr 0.9 Y 0.1 O 3 (BPY), have been synthesized. These compositions allowed for a comparison between A and B-site multivalent Pr (nominally 3+/4+); however, we found that the empirical model did not adequately predict the differences in CCEs on this basis. Other factors including crystal symmetry, charge localization, and location of charge (anion or cation) were instead found to be significantly impactful for both compositions [2]. Values of CCE have been determined by characterizing isothermal changes in stoichiometry with thermogravimetric analysis (TGA) and corresponding changes in strain with dilatometry and in situ, high temperature XRD (HTXRD) as a function of oxygen partial pressure (pO 2 ). The degree of charge localization has been interpreted from impedance measurements of the temperature dependence of conductivity, and the experimental results have been compared to density functional theory (DFT+U) calculations. Over the pO 2 and temperature range studied, PGM and BPY have low CCEs, therefore making them of potential interest for fuel/electrolysis cell electrodes. The effects of the abovementioned design rules are discussed to provide insights into rational material design for tailored CCE. [1] Marrocchelli, D., Perry, N. H., & Bishop, S. R. (2015). Understanding chemical expansion in perovskite-structured oxides. Physical Chemistry Chemical Physics , 17 (15), 10028-10039. [2] Ricote, S., Hudish, G., O’Brien, J. R. & Perry, N. H. Non stoichiometry and lattice expansion of BaZr0.9Dy0.1O3-δ in oxidizing atmospheres. Solid State Ionics (2019) doi:10.1016/j.ssi.2018.12.006.

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• Toward Durable Protonic Ceramic Cells: Hydration-Induced Chemical Expansion Correlates with Symmetry in the Y-Doped BaZrO₃–BaCeO₃ Solid Solution

  The Journal of Physical Chemistry C · 2021 · 40 citations

  • Materials science
  • Chemical engineering
  • Thermodynamics

  Electrolytes and electrodes in protonic ceramic electrolysis/fuel cells (PCECs/PCFCs) can exhibit significant chemical strains upon incorporating H2O into the lattice. To increase PCEC/PCFC durability, oxides with lower hydration coefficients of chemical expansion (CCEs) are desired. We hypothesized that lowering symmetry in perovskite-structured proton conductors would lower their CCEs and thus systematically varied the tolerance factor through B-site substitution in the prototypical BaCe0.9–xZrxY0.1O3−δ (0 ≤ x ≤ 0.9) solid solution. X-ray diffraction (XRD) confirmed that symmetry decreased with decreasing Zr content. CCEs were measured by isothermal XRD, dilatometry, and thermogravimetric analysis (TGA) in varied pH2O over 430–630 °C. With decreasing Zr content, the isothermal H2O uptake was greater, but the corresponding chemical strains were smaller; therefore, CCEs monotonically decreased. Density functional theory simulations on end-member BaCe1–yYyO3−δ and BaZr1–yYyO3−δ compositions showed the same trend. Lower CCEs in this solid solution correlate to decreasing symmetry, increasing unit cell volume, increasing oxygen vacancy radius, decreasing bulk modulus, and inter- vs intraoctahedral hydrogen bonding. Microstructural constraints may also contribute to lower macroscopic CCEs in lower-symmetry bulk ceramics based on the observed anisotropic chemical expansion and enhanced strains in powder vs bulk BaCe0.9Y0.1O3−δ. The results inform design principles for the rational tailoring of CCEs and materials choice for chemomechanically durable devices.

  PublisherDOI

• Toward Zero-Strain Mixed Conductors: Anomalously Low Redox Coefficients of Chemical Expansion in Praseodymium-Oxide Perovskites

  Chemistry of Materials · 2021 · 7 citations

  1st authorCorresponding
  • Materials science
  • Crystallography
  • Chemistry

  Zero-strain materials are desired for high chemo-mechanical stability in energy conversion/storage devices, where operational stoichiometry changes can cause large chemical stresses. Here, we demonstrate near-zero redox coefficients of chemical expansion (CCEs) for mixed- and triple-conducting Pr-oxide perovskites. PrGa0.9Mg0.1O3 – δ (PGM) and BaPr0.9Y0.1O3 – δ (BPY), having Pr on the A- and B-site, respectively, were synthesized and characterized with in situ high temperature, variable atmosphere X-ray diffraction, dilatometry, and thermogravimetric analysis to obtain isothermal stoichiometry changes, chemical strains, and CCEs. Despite empirical model predictions of smaller CCEs for Pr on the A-site, both compositions yielded unprecedented low average CCEs (0.004–0.011), 2–5× lower than the lowest reported perovskite redox CCEs. Simple empirical models assume pseudo-cubic structures and full charge localization on multivalent cations like Pr. To evaluate actual charge distribution, in situ impedance spectroscopy and density functional theory calculations were performed. Results indicate that the anomalously low CCEs in these compositions likely derive from a combination of decreased crystal symmetry (vs cubic), partial charge delocalization through hybridization of Pr-4f and O-2p orbitals, and redox/multivalence on O rather than just Pr (with or without hybridization). On this basis, we suggest band structure design principles for near-zero redox-strain perovskites, highlighting the benefit of locating holes partially or fully on oxygen.

  PublisherDOI

• Improving Chemo-Mechanical Stability of Proton-Conducting Perovskites

  ECS Meeting Abstracts · 2020-05-01

  article

  The superior ionic conductivity of selected proton-conducting perovskites enables development of intermediate temperature electrochemical devices, such as solid oxide fuel/electrolysis cells, gas separation membranes, and electrochemical reactors. The lower operating temperature, compared to those of most oxide ion-conductors, can benefit the durability of the devices, as most degradation mechanisms are thermally activated. On the other hand, the chemical strains associated with hydration/dehydration during processing or operation can be considerably larger than those seen in their oxide ion-conducting counterparts during oxygen loss/gain. There is therefore a significant need to develop proton conductors with lower coefficients of chemical expansion (CCE), which is the chemical strain normalized to the change in defect (proton) concentration. Since design principles for engineering CCEs are not well developed, we have previously been investigating the role of various structural and chemical features, such as size of the oxygen vacancy and charge localization. In this presentation, I will focus on our more recent work investigating the role of octahedral distortions and deviations away from the perfect cubic perovskite structure. By substituting differently sized isovalent cations on the A- and B-site of perovskites, it is possible to engineer the tolerance factor to vary the symmetry and distortions. We have therefore synthesized a series of (Ba,Sr)(Zr,Ce) 0.9 Y 0.1 O 3-x perovskites with gradually varying tolerance factor. To measure hydration strains, isothermal in situ X-ray diffraction and dilatometry were performed at temperature points in the range ~360-680 °C, in varying humidities. To evaluate the corresponding changes in proton concentration, isothermal thermogravimetric analysis was applied under identical conditions; an intermediate, constant oxygen partial pressure was chosen to avoid the possibility of any simultaneous redox reactions contributing significantly to mass changes and strains. The combined results show that by diminishing the perovskite tolerance factor in this family of zirconate/cerate proton conductors, the coefficient of chemical expansion can be lowered by 500%. Further in situ X-ray diffraction analysis of powder vs. bulk samples, and density functional theory simulations of single crystals, have revealed that there are both crystal chemical and microstructural contributions to the trend seen. The results show that inducing octahedral rotations and lowering symmetry, by altering the cation radius ratio, is an effective route to increase chemo-mechanical stability by lowering CCEs.

  PublisherDOI

Frequent coauthors

• Nicola H. Perry

  University of Illinois Urbana-Champaign

  12 shared

• Yanan Chen

  Wuhan University of Technology

  12 shared

• Guangfu Li

  Ji Hua Laboratory

  11 shared

• Po‐Ya Abel Chuang

  University of California, Merced

  10 shared

• Elif Ertekin

  University of Illinois Urbana-Champaign

  5 shared

• Adrian Xiao Bin Yong

  University of Illinois Urbana-Champaign

  5 shared

• Mu Pan

  Ji Hua Laboratory

  3 shared

• N. R. Aluru

  Walker (United States)

  2 shared

Education

• PhD, Materials Science

  University of Illinois at Urbana-Champaign

• Bachelors, Materials Science & Engineering

  University of California Merced

  2018