Blar i SINTEF Open på forfatter "Fjellvåg, Helmer"
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Characterization and evaluation of synthetic Dawsonites as CO2 sorbents
Lundvall, Fredrik; Kalantzopoulos, Georgios N.; Wragg, David; Arstad, Bjørnar; Blom, Richard; Sjåstad, Anja Olafsen; Fjellvåg, Helmer (Journal article; Peer reviewed, 2019) -
Effect ofl larger pore size on the sorption properties of isoreticular metal–organic frameworks with high number of open metal sites
Dietzel, Pascal D.C.; Georgiev, Peter A.; Frøseth, Morten; Johnsen, Rune E.; Fjellvåg, Helmer; Blom, Richard (Peer reviewed; Journal article, 2020)Four isostructural CPO‐54‐M metal‐organic frameworks based on the larger organic linker 1,5‐dihydroxynaphthalene‐2,6‐dicarboxylic acid and divalent cations (M=Mn, Mg, Ni, Co) are shown to be isoreticular to the CPO‐27 ... -
Factors Determining Microporous Material Stability in Water: The Curious Case of SAPO-37
Kalantzopoulos, Georgios N.; Lundvall, Fredrik; Thorshaug, Knut; Lind, Anna Maria; Vajeeston, Ponniah; Dovgaliuk, Iurii; Arstad, Bjørnar; Wragg, David; Fjellvåg, Helmer (Peer reviewed; Journal article, 2020)Silicoaluminophosphates (SAPOs) are a special class of zeolites that, due to their acidic and shape-selective properties, play a major role in ion exchange and separation processes and in crude oil cracking. SAPO-37 has ... -
Jahn-Teller active fluoroperovskites ACrF3 (A=Na+, K+): Magnetic and thermo-optical properties
Bernal, Fabian Leonardo Martinez; Lundvall, Fredrik; Kumar, Susmit; Hansen, Per-Anders S.; Wragg, David S.; Fjellvåg, Helmer; Løvvik, Ole Martin (Peer reviewed; Journal article, 2021)Chromium (II) fluoroperovskites A CrF 3 ( A = Na + , K + ) are strongly correlated Jahn-Teller active materials at low temperatures. In this paper, we examine the role that the A -site ion plays in this family of ... -
MgH2–CoO: a conversion-type composite electrode for LiBH4-based all-solid-state lithium ion batteries
El-Kharbachi, Abdelouahab; Uesato, Hiroki; Kawai, Hironori; Wenner, Sigurd; Miyaoka, Hiroki; Sørby, Magnus Helgerud; Fjellvåg, Helmer; Ichikawa, Takayuki; Hauback, Bjørn (Journal article; Peer reviewed, 2018)Several studies have demonstrated that MgH2 is a promising conversion-type anode toward Li. A major obstacle is the reversible capacity during cycling. Electrochemical co-existence of a mixed metal hydride-oxide conversion ... -
Reversibility of metal-hydride anodes in all-solid-state lithium secondary battery operating at room temperature
El-Kharbachi, Abdelouahab; Hu, Yang; Sørby, Magnus Helgerud; Mæhlen, Jan Petter; Vullum, Per Erik; Fjellvåg, Helmer; Hauback, Bjørn (Journal article; Peer reviewed, 2018)The impact on the performance of conversion-type MgH2 anodes by using solid state electrolyte is reported. MgH2 anodes (~26 μm thick) made from homogenous slurries and subsequent drying, are used as model systems along ... -
SAPO-37 microporous catalysts: revealing the structural transformations during template removal
Kalantzopoulos, Georgios N.; Lundvall, Fredrik; Lind, Anna Maria; Arstad, Bjørnar; Chernyshov, Dmitry; Fjellvåg, Helmer; Wragg, David (Peer reviewed; Journal article, 2017)We have studied the structural behavior of SAPO-37 during calcination using simultaneous in situ powder X-ray diffraction (PXRD) and mass spectroscopy (MS) in addition to ex situ thermogravimetric analysis (TGA) and ... -
Structural changes in SAPO-34 due to hydrothermal treatment. A NMR, XRD, and DRIFTS study
Arstad, Bjørnar; Lind, Anna Maria; Cavka, Jasmina Hafizovic; Thorshaug, Knut; Akporiaye, Duncan; Wragg, David; Fjellvåg, Helmer; Grønvold, Arne; Fuglerud, Terje (Peer reviewed; Journal article, 2016)When SAPO-34 is used as an industrial MTO catalyst, structural transformations leading to permanent deactivation are inevitable. The performance loss is linked principally to a redistribution of Si in the material, leading ... -
Synthesis and Evaluation of K-Promoted Co3-xMgxAl-Oxides as Solid CO2 Sorbents in the Sorption-Enhanced Water−Gas Shift (SEWGS) Reaction
Arstad, Bjørnar; Blom, Richard; Håkonsen, Silje Fosse; Pierchala, Joanna; Cobden, Paul; Lundvall, Fredrik; Kalantzopoulos, Georgios N.; Wragg, David; Fjellvåg, Helmer; Sjåstad, Anja Olafsen (Peer reviewed; Journal article, 2020)Hydrogen is essential in a variety of large-scale chemical processes. As a carbon-free energy carrier, hydrogen has a potential for wide use within power production and transportation. However, most of the recent production ... -
Thermogravimetric Analysis – A Viable Method for Screening Novel Materials for the Sorbent Enhanced Water-gas Shift Process
Lundvall, Fredrik; Kalantzopoulos, Georgios N.; Wragg, David; Arstad, Bjørnar; Blom, Richard; Sjåstad, Anja Olafsen; Fjellvåg, Helmer (Peer reviewed; Journal article, 2017)Pre-combustion CO2 capture technologies are becoming viable alternatives to more conventional post-combustion capture by gas emissions scrubbing. The sorbent enhanced water-gas shift (SEWGS) process is a promising future ... -
Variability in the formation and framework polymorphism of metal-organic frameworks based on yttrium(III) and the bifunctional organic linker 2,5-dihydroxyterephthalic acid
Dietzel, Pascal D.C.; Blom, Richard; Fjellvåg, Helmer (Peer reviewed; Journal article, 2020)Depending on the solvothermal reaction conditions, we obtained three different metal‐organic frameworks with yttrium(III) as metal component and 2,5‐dihdyroxyterepthalic acid (H4dhtp) as bifunctional organic linker: ...