Blar i SINTEF Open på forfatter "Polfus, Jonathan M."
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Adsorption of CO2 and Facile Carbonate Formation on BaZrO3 Surfaces
Polfus, Jonathan M.; Yildiz, Bilge; Tuller, Harry; Bredesen, Rune (Journal article; Peer reviewed, 2018)The adsorption of CO2 and CO on BaZrO3 (0 0 1) was investigated by first-principles calculations with a focus on the BaO termination. CO2 was found to strongly chemisorb on the surface by formation of carbonate species ... -
Chemical stability and H2 flux degradation of cercer membranes based on lanthanum tungstate and lanthanum chromite
Polfus, Jonathan M.; Li, Zuoan; Xing, Wen; Sunding, Martin Fleissner; Walmsley, John; Fontaine, Marie-Laure; Henriksen, Partow Pakdel; Bredesen, Rune (Peer reviewed; Journal article, 2016)Ceramic–ceramic composite (cercer) membranes of (Mo-doped) lanthanum tungstate, La27(W,Mo)5O55.5−δ, and lanthanum chromite, La0.87Sr0.13CrO3−δ, have recently been shown to exhibit H2 permeabilities among state-of-the-art. ... -
Doping strategies for increased oxygen permeability of CaTiO3 based membranes
Polfus, Jonathan M.; Xing, Wen; Sunding, Martin Fleissner; Hanetho, Sidsel Meli; Dahl, Paul Inge; Larring, Yngve; Fontaine, Marie-Laure; Bredesen, Rune (Peer reviewed; Journal article, 2015)Oxygen permeation measurements are performed on dense samples of CaTi0.85Fe0.15O3−δ, CaTi0.75Fe0.15Mg0.05O3−δ and CaTi0.75Fe0.15Mn0.10O3−δ in combination with density functional theory (DFT) calculations and X-ray photoelectron ... -
Enhanced O2 flux of CaTi0.85Fe0.15O3 – d based membranes by Mn doping
Polfus, Jonathan M.; Xing, Wen; Riktor, Marit Dalseth; Sunding, Martin Fleissner; Dahl, Paul Inge; Hanetho, Sidsel Meli; Mokkelbost, Tommy; Larring, Yngve; Fontaine, Marie-Laure; Bredesen, Rune (Peer reviewed; Journal article, 2016)Dense symmetric membranes of CaTi0.85−xFe0.15MnxO3−δ (x = 0.1, 0.15, 0.25, 0.4) are investigated in order to determine the optimal Mn dopant content with respect to highest O2 flux. O2 permeation measurements are performed ... -
Hydrogen separation membranes based on dense ceramic composites in the La27W5O55.5–LaCrO3 system
Polfus, Jonathan M.; Xing, Wen; Fontaine, Marie-Laure; Denonville, Christelle; Henriksen, Partow Pakdel; Bredesen, Rune (Peer reviewed; Journal article, 2015)Some compositions of ceramic hydrogen permeable membranes are promising for integration in high temperature processes such as steam methane reforming due to their high chemical stability in large chemical gradients and CO2 ... -
Influence of Ce3+ polarons on grain boundary space-charge in proton conducting Y-doped BaCeO3
Polfus, Jonathan M.; Pishahang, Mehdi; Bredesen, Rune (Peer reviewed; Journal article, 2018)Defect segregation and space-charge formation were investigated for a (0 2 1)[1 0 0] symmetric tilt grain boundary in Y-doped BaCeO3. Density functional theory calculations according to the PBE+U formalism were used to ... -
Interplay between H2O and CO2 coadsorption and space-charge on Y-doped BaZrO3 surfaces
Polfus, Jonathan M.; Yang, Jing; Yildiz, Bilge (Peer reviewed; Journal article, 2018)The present work quantifies the equilibrium defect and adsorbate chemistry on oxide surfaces in the presence of multiple gas components at elevated temperatures and sub-surface space charge. The concentrations of chemisorbed ... -
Nanocomposites of few-layer graphene oxide and alumina by density functional theory calculations
Polfus, Jonathan M.; Løvvik, Ole Martin; Rørvik, Per Martin; Bredesen, Rune (Peer reviewed; Journal article, 2016)The atomistic and electronic structure and oxygen stoichiometry of nanocomposites between alumina and graphene oxide were investigated by density functional theory calculations. The nanocomposite was described as interfaces ... -
On the mechanism of Mn(II)-doping in Scandia stabilized zirconia electrolytes
Vøllestad, Einar; Øygarden, Vegar; Graff, Joachim Seland; Sunding, Martin Fleissner; Pietras, John D.; Polfus, Jonathan M.; Fontaine, Marie-Laure (Peer reviewed; Journal article, 2022)Cubic Scandia-stabilized zirconia (ScSZ) is an attractive electrolyte material for solid oxide cells due to its significant ionic conductivity, provided that the phase transition to its rhombohedral polymorph upon cooling ... -
Oxygen permeation and creep behavior of Ca1-xSrxTi0.6Fe0.15Mn0.25O3-δ (x=0, 0.5) membrane materials
Polfus, Jonathan M.; Xing, Wen; Pecanac, Goran; Fossdal, Anita; Hanetho, Sidsel Meli; Larring, Yngve; Malzbender, Jürgen; Fontaine, Marie-Laure; Bredesen, Rune (Peer reviewed; Journal article, 2016)Oxygen permeation measurements were performed on dense symmetric samples of Ca0.5Sr0.5Ti0.6Fe0.15Mn0.25O3−δ and compared to CaTi0.6Fe0.15Mn0.25O3−δ in order to assess the influence of the perovskite lattice volume on oxygen ... -
Proton segregation and space-charge at the BaZrO3 (0 0 1)/MgO (0 0 1) heterointerface
Polfus, Jonathan M.; Norby, Truls Eivind; Bredesen, Rune (Peer reviewed; Journal article, 2016)Y-doped BaZrO3 (BZY) can be deposited epitaxially on MgO (0 0 1) and the considered interface serves as a model system for studying heterointerface properties of protonic conductors. In this study, the defect chemistry of ... -
Protons in Oxysulfates, and Sulfides: A First-Principles Study of La2O2S, La2O2SO4, SrZrS3, and BaZrS3
Polfus, Jonathan M.; Norby, Truls; Bredesen, Rune (Peer reviewed; Journal article, 2015)Sulfur-containing materials may be of importance in devices such as proton conducting fuel cells for energy conversion involving fossil or bioderived fuels. First-principles calculations were employed to elucidate the ... -
Robust nanocomposites of a-Fe2O3 and N-doped graphene oxide: Interfacial bonding and chemisorption of H2O
Polfus, Jonathan M.; Jayasayee, Kaushik (Peer reviewed; Journal article, 2019)Nanocomposites of α-Fe2O3 (hematite) and (N-doped) graphene oxide (GO) were investigated using first-principles calculations with focus on structure, chemical bonding, electronic structure and H2O adsorption. The nanocomposites ... -
Temperature-Dependent Adhesion in van der Waals Heterostructures
Polfus, Jonathan M.; Benthem, Marta; Ali, Ayaz; Barragan-Yani, Daniel; Vullum, Per Erik; Sunding, Martin Fleissner; Taniguchi, Takashi; Watanabe, Kenji; Belle, Branson (Peer reviewed; Journal article, 2021)The interlayer coupling between 2D materials is immensely important for both the fundamental understanding of these systems, and for the development of transfer techniques for the fabrication of van der Waals (vdW) ... -
Thermochemically stable ceramic compositemembranes based on Bi2O3 for oxygen separationwith high permeability
Xing, Wen; Almeida Carvalho, Patricia; Polfus, Jonathan M.; Li, Zuoan (Journal article; Peer reviewed, 2019)Ceramic oxygen separation membranes can be utilized to reduce CO2 emissions in fossil fuel power generation cycles based on oxy-fuel combustion. State-of-the-art oxygen permeable membranes based on Ba0.5Sr0.5Co0.8Fe0.2O3−δ ...