Truls Norby

• Qureishy, Thomas; Løyland, Sverre; Jørgensen, Susanne Jøntvedt; Færgestad, Eline Mosleth; Norby, Truls & Uggerud, Einar (2022). Mechanisms for sonochemical oxidation of nitrogen. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 24(25), p. 15357–15364. doi: 10.1039/d2cp01995g.
• Sun, Xinwei; Gu, Jie; Han, Donglin & Norby, Truls (2022). Quantifiable models for surface protonic conductivity in porous oxides - case of monoclinic ZrO<inf>2</inf>. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 24(19), p. 11856–11871. doi: 10.1039/d1cp05668a.
• Catalán-Martínez, D.; Navarrete, L.; Tarach, M.; Santos-Blasco, J.; Vøllestad, Einar & Norby, Truls [Show all 9 contributors for this article] (2022). Thermo-fluid dynamics modelling of steam electrolysis in fully-assembled tubular high-temperature proton-conducting cells. International Journal of Hydrogen Energy. ISSN 0360-3199. doi: 10.1016/j.ijhydene.2022.06.112.
• Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein [Show all 9 contributors for this article] (2022). Galvanic Restructuring of Exsolved Nanoparticles for Plasmonic and Electrocatalytic Energy Conversion. Small. ISSN 1613-6810. 18(29). doi: 10.1002/smll.202201106. Full text in Research Archive
• Zhong, Peng; Toyoura, Kazuaki; Jiang, Lulu; Chen, Lubing; Ismail, Sara Adeeba & Hatada, Naoyuki [Show all 8 contributors for this article] (2022). Protonic Conduction in La2NiO4+δ and La2-xAxNiO4+δ (A = Ca, Sr, Ba) Ruddlesden–Popper Type Oxides. Advanced Energy Materials. ISSN 1614-6832. doi: 10.1002/aenm.202200392.
• Clark, Daniel Ryan; Malerød-Fjeld, Harald; Budd, Michael; Yuste Tirados, Irene; Beeaff, Dustin & Aamodt, Simen [Show all 17 contributors for this article] (2022). Single-step hydrogen production from NH3, CH4, and biogas in stacked proton ceramic reactors. Science. ISSN 0036-8075. 376(6591), p. 390–393. doi: 10.1126/science.abj3951. Show summary

  An alternative to directly transporting hydrogen produced at large scales through steam reforming for applications such as vehicular fueling is smaller scale, on-site production from methane or carriers such as ammonia. The hydrogen produced must be separated from co-produced carbon dioxide or nitrogen. Proton ceramic electrochemical reactors can extract pure hydrogen from gas mixtures by electrolytically pumping protons across the membrane at 800°C, but as the extraction proceeds, temperature gradients and entropic effects lead to efficiency drops. Clark et al. developed a nickel-based glass-ceramic composite interconnect that allowed for the design of a more complex reactor pathway (see the Perspective by Shih and Haile). Counterflowing streams balanced heat flows and maintained stable operating conditions that enabled 99% efficiency of hydrogen recovery. —PDS

• Madathil, Reshma Krishnan; Schuler, Raphael & Norby, Truls (2022). La1-xSrxMO3 (M = Co, Mn, Cr) interconnects in a 4-leg all-oxide thermoelectric generator at high temperatures. Journal of Physics and Chemistry of Solids. ISSN 0022-3697. 167. doi: 10.1016/j.jpcs.2022.110739. Full text in Research Archive
• Vijayan Sobhana, Dilimon; Strandbakke, Ragnar & Norby, Truls (2022). Impedance spectroscopy study of Au electrodes on Gd-doped CeO<inf>2</inf> (GDC) – Molten Li<inf>2</inf>CO<inf>3</inf>+Na<inf>2</inf>CO<inf>3</inf> (LNC) composite electrolytes. Journal of Power Sources. ISSN 0378-7753. 522. doi: 10.1016/j.jpowsour.2022.230986. Full text in Research Archive
• Madathil, Reshma Krishnan & Norby, Truls Eivind (2022). Lanthanum strontium cobaltite as interconnect in oxide thermoelectric generators. Solid State Sciences. ISSN 1293-2558. 124. doi: 10.1016/j.solidstatesciences.2021.106801. Full text in Research Archive
• Ismail, Sara Adeeba; Jiang, Lulu; Zhong, Peng; Norby, Truls Eivind & Han, Donglin (2022). La<inf>2</inf>Ce<inf>2</inf>O<inf>7</inf> doped with alkaline earth elements: Phase behavior, hydration and electrical properties. Journal of Alloys and Compounds. ISSN 0925-8388. 899. doi: 10.1016/j.jallcom.2021.163306.
• Liu, Xin; Risbakk, Sanne; Almeida Carvalho, Patricia; Yang, Mingyi; Backe, Paul Hoff & Bjørås, Magnar [Show all 8 contributors for this article] (2022). Immobilization of FeFe-hydrogenase on black TiO2 nanotubes as biocathodes for the hydrogen evolution reaction. Electrochemistry communications. ISSN 1388-2481. 135. doi: 10.1016/j.elecom.2022.107221. Full text in Research Archive
• Kang, Xiaolan; Chatzitakis, Athanasios; Aarholt, Thomas; Sun, Xinwei; Negri, Chiara & Norby, Truls (2022). Facet-engineered TiO<inf>2</inf>nanomaterials reveal the role of water-oxide interactions in surface protonic conduction. Journal of Materials Chemistry A. ISSN 2050-7488. 10(1), p. 218–227. doi: 10.1039/d1ta06075a. Full text in Research Archive
• Hisai, Yudai; Ma, Quanbao; Qureishy, Thomas; Watanabe, Takeshi; Higo, Takuma & Norby, Truls [Show all 7 contributors for this article] (2021). Enhanced activity of catalysts on substrates with surface protonic current in an electrical field – a review. Chemical Communications. ISSN 1359-7345. 57, p. 5737–5749. doi: 10.1039/d1cc01551f. Full text in Research Archive
• Sata, Noriko; Han, Feng; Zheng, Haoyu; Dayaghi, Amir Masoud; Norby, Truls & Stange, Marit Synnøve Sæverud [Show all 8 contributors for this article] (2021). Development of Proton Conducting Ceramic Cells in Metal Supported Architecture . ECS Transactions. ISSN 1938-5862. 103(1), p. 1779–1789. doi: 10.1149/10301.1779ecst.
• Kang, Xiaolan; Chaperman, Larissa; Galeckas, Augustinas; Ammar, Souad; Mammeri, Fayna & Norby, Truls [Show all 7 contributors for this article] (2021). Water Vapor Photoelectrolysis in a Solid-State Photoelectrochemical Cell with TiO2 Nanotubes Loaded with CdS and CdSe Nanoparticles. ACS Applied Materials & Interfaces. ISSN 1944-8244. 13(39), p. 46875–46885. doi: 10.1021/acsami.1c13047. Full text in Research Archive
• Ćwieka, K.; Lysik, A.; Wejrzanowski, T.; Norby, Truls Eivind & Xing, Wen (2021). Microstructure and electrochemical behavior of layered cathodes for molten carbonate fuel cell. Journal of Power Sources. ISSN 0378-7753. 500. doi: 10.1016/j.jpowsour.2021.229949. Full text in Research Archive
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Backe, Paul Hoff; Ruan, Qiushi; Tang, Junwang & Rise, Frode [Show all 8 contributors for this article] (2021). In situ cofactor regeneration enables selective CO2 reduction in a stable and efficient enzymatic photoelectrochemical cell. Applied Catalysis B: Environmental. ISSN 0926-3373. 296. doi: 10.1016/j.apcatb.2021.120349. Full text in Research Archive Show summary

  Mimicking natural photosynthesis by direct photoelectrochemical (PEC) reduction of CO2 to chemicals and fuels requires complex cell assemblies with limitations in selectivity, efficiency, cost, and stability. Here, we present a breakthrough cathode utilizing an oxygen tolerant formate dehydrogenase enzyme derived from clostridium carboxidivorans and coupled to a novel and efficient in situ nicotinamide adenine dinucleotide (NAD+/NADH) regeneration mechanism through interfacial electrochemistry on g-C3N4 films. We demonstrate stable (20 h) aerobic PEC CO2-to-formate reduction at close to 100 % faradaic efficiency and unit selectivity in a bio-hybrid PEC cell of minimal engineering with optimized Ta3N5 nanotube photoanode powered by simulated sunlight with a solar to fuel efficiency of 0.063 %, approaching that of natural photosynthesis.

• Zhu, Junjie; Gudmundsdottir, Jonina Björg; Strandbakke, Ragnar; Both, Kevin Gregor; Aarholt, Thomas & Almeida Carvalho, Patricia [Show all 12 contributors for this article] (2021). Double Perovskite Cobaltites Integrated in a Monolithic and Noble Metal-Free Photoelectrochemical Device for Efficient Water Splitting. ACS Applied Materials & Interfaces. ISSN 1944-8244. 13(17), p. 20313–20325. doi: 10.1021/acsami.1c01900. Full text in Research Archive
• Schuler, Raphael; Madathil, Reshma Krishnan & Norby, Truls (2021). Versatile four-leg thermoelectric module test setup adapted to a commercial sample holder system for high temperatures and controlled atmospheres. Review of Scientific Instruments. ISSN 0034-6748. 92(4). doi: 10.1063/5.0032698.
• Schuler, Raphael; Bianchini, Federico; Norby, Truls Eivind & Fjellvåg, Helmer (2021). Near-Broken-Gap Alignment between FeWO4 and Fe2WO6 for Ohmic Direct p–n Junction Thermoelectrics. ACS Applied Materials & Interfaces. ISSN 1944-8244. 13(6), p. 7416–7422. doi: 10.1021/acsami.0c19341.
• Kang, Xiaolan; Berberidou, Chrysanthi; Galeckas, Augustinas; Bazioti, Kalliopi; Sagstuen, Einar & Norby, Truls Eivind [Show all 8 contributors for this article] (2021). Visible Light Driven Photocatalytic Decolorization and Disinfection of Water Employing Reduced TiO2 Nanopowders. Catalysts. ISSN 2073-4344. 11(2). doi: 10.3390/catal11020228. Full text in Research Archive
• Mayandi, Jeyanthinath; Madathil, Reshma Krishnan; Abinaya, C; Bethke, Kevin; Venkatachalapathy, Vishnukanthan & Rademann, Klaus [Show all 8 contributors for this article] (2021). Al-doped ZnO prepared by co-precipitation method and its thermoelectric characteristics. Materials Letters. ISSN 0167-577X. 288. doi: 10.1016/j.matlet.2021.129352. Show summary

  We report on structural and electrical characterization of zinc oxide material containing aluminum (Al:ZnO) prepared by a co-precipitation technique using different zinc and aluminum precursors. The as-prepared powders were calcinated and pre-annealed at 600 °C and 1200 °C. These were cold-pressed to pellets and sintered at 1000 °C. We also prepared ZnO material with no Al for comparisons. The electrical and thermal conductivity, as well as the Seebeck coefficient, were measured. These properties were correlated with structural analysis by X-ray diffraction characterization and scanning electron microscopy. The process yields a nanostructured material with much reduced thermal conductivity.

• Dayaghi, Amir Masoud; Haugsrud, Reidar; Stange, Marit Synnøve Sæverud; Larring, Yngve; Strandbakke, Ragnar & Norby, Truls Eivind (2021). Increasing the thermal expansion of proton conducting Y-doped BaZrO3 by Sr and Ce substitution. Solid State Ionics. ISSN 0167-2738. 359. doi: 10.1016/j.ssi.2020.115534. Full text in Research Archive
• Bondevik, Tarjei; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2020). Assessing common approximations in space charge modelling to estimate the proton resistance across grain boundaries in Y-doped BaZrO3. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 22(21), p. 11891–11902. doi: 10.1039/c9cp06625j.
• Lysik, Aleksandra; Wejrzanowski, Tomasz; Cwieka, Karol; Skibinski, Jakub; Milewski, Jaroslaw & Marques, Fernando M.B. [Show all 8 contributors for this article] (2020). Silver coated cathode for molten carbonate fuel cells. International Journal of Hydrogen Energy. ISSN 0360-3199. 45(38), p. 19847–19857. doi: 10.1016/j.ijhydene.2020.05.112.
• Hu, Yang; Miikkulainen, Ville; Mizohata, Kenichiro; Norby, Truls Eivind; Nilsen, Ola & Fjellvåg, Helmer (2020). Ionic conductivity in LixTaOy thin films grown by Atomic Layer Deposition (ALD). Electrochimica Acta. ISSN 0013-4686. 361. doi: 10.1016/j.electacta.2020.137019. Full text in Research Archive
• Kalland, Liv-Elisif Queseth; Løken, Andreas; Bjørheim, Tor Svendsen; Haugsrud, Reidar & Norby, Truls Eivind (2020). Structure, hydration, and proton conductivity in 50% La and Nd doped CeO2 – La2Ce2O7 and Nd2Ce2O7 – and their solid solutions. Solid State Ionics. ISSN 0167-2738. 354. doi: 10.1016/j.ssi.2020.115401. Full text in Research Archive
• Michel, Kathrin; Bjørheim, Tor Svendsen; Norby, Truls Eivind; Janek, Jürgen & Elm, Matthias (2020). Importance of the spin-orbit interaction for a consistent theoretical description of small polarons in Pr-doped CeO2. Journal of Physical Chemistry C. ISSN 1932-7447. 124(29), p. 15831–15838. doi: 10.1021/acs.jpcc.0c05352.
• Sun, Xinwei; Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind (2020). Photocatalytic generation of gas phase reactive oxygen species from adsorbed water: Remote action and electrochemical detection. Journal of Environmental Chemical Engineering. ISSN 2213-3437. doi: 10.1016/j.jece.2020.104809. Full text in Research Archive
• Szpunar, Iga; Strandbakke, Ragnar; Sørby, Magnus Helgerud; Wachowski, Sebastian Lech; Balaguer, Maria & Tarach, Mateusz [Show all 12 contributors for this article] (2020). High-temperature structural and electrical properties of BaLnCo2O6 positrodes. Materials. ISSN 1996-1944. 13(18), p. 1–18. doi: 10.3390/ma13184044. Full text in Research Archive
• Getz, Marit Norderhaug; Chatzitakis, Athanasios Eleftherios; Liu, Xin; Almeida Carvalho, Patricia; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2020). Voids in walls of mesoporous TiO2 anatase nanotubes by controlled formation and annihilation of protonated titanium vacancies. Materials Chemistry and Physics. ISSN 0254-0584. 239. doi: 10.1016/j.matchemphys.2019.121953.
• Torimoto, Maki; Ogo, Shuhei; Hisai, Yudai; Takahashi, Ayako; Ma, Quanbao & Seo, Jeong Gil [Show all 9 contributors for this article] (2020). Support effects on catalysis of low temperature methane steam reforming. RSC Advances. ISSN 2046-2069. 10, p. 26418–26424 . doi: 10.1039/d0ra04717a. Full text in Research Archive
• Takahashi, Ayako; Inagaki, Reona; Torimoto, Maki; Hisai, Yudai; Matsuda, Taku & Ma, Quanbao [Show all 12 contributors for this article] (2020). Effects of metal cation doping in CeO2 support on catalytic methane steam reforming at low temperature in an electric field . RSC Advances. ISSN 2046-2069. 10, p. 14487–14492 . doi: 10.1039/d0ra01721c. Full text in Research Archive
• Wachowski, Sebastian Lech; Szpunar, Iga; Sørby, Magnus Helgerud; Mielewczyk-Gryń, Aleksandra; Balaguer, Maria & Ghica, Corneliu [Show all 12 contributors for this article] (2020). Structure and water uptake in BaLnCo2O6−δ (Ln = La, Pr, Nd, Sm, Gd, Tb and Dy). Acta Materialia. ISSN 1359-6454. 199, p. 297–310. doi: 10.1016/j.actamat.2020.08.018. Full text in Research Archive
• Saeed, Sarmad Waheed; Norby, Truls & Bjørheim, Tor S. (2020). First-Principles Analyses of Nanoionic Effects at Oxide-Oxide Heterointerfaces for Electrochemical Applications. Journal of Physical Chemistry C. ISSN 1932-7447. 124(26), p. 14072–14081. doi: 10.1021/acs.jpcc.0c00385. Full text in Research Archive
• Schuler, Raphael; Norby, Truls Eivind & Fjellvåg, Helmer (2020). Defects and polaronic electron transport in Fe2WO6. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 22(27), p. 15541–15548. doi: 10.1039/d0cp01588a. Full text in Research Archive
• Bondevik, Tarjei; Polfus, Jonathan Marc & Norby, Truls Eivind (2020). Disagreements between space charge models and grain boundary impedance data in yttrium-substituted barium zirconate. Solid State Ionics. ISSN 0167-2738. 353. doi: 10.1016/j.ssi.2020.115369. Full text in Research Archive Show summary

  Although the space charge model is commonly used to explain the high grain boundary resistance in proton conducting yttrium-substituted BaZrO3, it fails in its simplest forms with factors 10–40 to fit experimental data with respect to the characteristic frequency of the grain boundary impedance. We suggest modifications to the model, somewhat improving its fit. Including trapping effects of protons near yttrium substituents reduces the error only by factors less than 1.6. Increasing the width of the grain boundary core reduces the error with factors of 1.5–3. Discretizing the space charge layer, such that protons can only reside on specific, discrete sites, reduces the error with another factor of around 2. Considering reduced proton mobility in the GB by reducing its effective area may give a reduction in the fitting error of a factor of 2. Varying the dielectric constant in the GB does not affect the error considerably. Neither each single modification, nor their combined effect, can, however, account for the majority of the discrepancy between the space charge model and experimental data.

• Hisai, Yudai; Murakami, Kota; Kamite, Yukiko; Ma, Quanbao; Vøllestad, Einar & Manabe, Ryo [Show all 10 contributors for this article] (2020). First observation of surface protonics on SrZrO3 perovskite under a H2 atmosphere. Chemical Communications. ISSN 1359-7345. 56, p. 2699–2702. doi: 10.1039/C9CC08757E. Full text in Research Archive
• Gunnæs, Anette Eleonora; Tofan, Raluca; Berland, Kristian; Gorantla, Sandeep Madhukar; Storaas, Thomas Aarflot & Desissa, Temesgen Debelo [Show all 12 contributors for this article] (2020). Chemical stability of Ca3Co4−xO9+δ/CaMnO3−δ p–n junction for oxide-based thermoelectric generators. RSC Advances. ISSN 2046-2069. 10(9), p. 5026–5031. doi: 10.1039/c9ra07159h. Full text in Research Archive
• Barakezehi, Marjan; Montazer, Majid; Sharif, Farhad; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2020). MOF-modified polyester fabric coated with reduced graphene oxide/polypyrrole as electrode for flexible supercapacitors. Electrochimica Acta. ISSN 0013-4686. 336. doi: 10.1016/j.electacta.2020.135743. Full text in Research Archive

View all works in Cristin

• Stange, Marit Synnøve Sæverud; Denonville, Christelle; Stefan, Elena; Dayaghi, Amir Masoud; Larring, Yngve & Rørvik, Per Martin [Show all 9 contributors for this article] (2022). Fabrication and testing of thin-film based metal-supported proton ceramic electrochemical cells.
• Dayaghi, Amir Masoud; Polfus, Jonathan; Strandbakke, Ragnar; Vøllestad, Einar; Haugsrud, Reidar & Norby, Truls (2022). Effects of NiO, ZnO and CuO sintering additives on the hydration of BaZr0.4Ce0.4(Y,Yb)0.2O3-δ proton conducting electrolytes.
• Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein [Show all 9 contributors for this article] (2022). Galvanic Restructuring of Exsolved Nanoparticles for Plasmonic and Electrocatalytic Energy Conversion (Small 29/2022 Isinde back cover feature). Small. ISSN 1613-6810. 18(29).
• Norby, Truls; Karsthof, Robert Michael; Saeed, Sarmad Waheed; Kuznetsov, Andrej & Vines, Lasse (2022). The p-n junction has nothing to do with ionics. Does it? .
• Sun, Xinwei; Vøllestad, Einar & Norby, Truls (2022). Surface protonic conductivity in chemisorbed and physisorbed water layers in porous nanoscopic CeO2 .
• Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein [Show all 9 contributors for this article] (2022). Galvanic restructuring of exsolved nanoparticles for plasmonic and electrocatalytic energy conversion .
• Pedersen, Madeeha Khalid & Norby, Truls (2022). Defect Models for Li-Ion Transport in Al- and Nb-Doped LLZO.
• Norby, Truls (2022). Defects and transport in inherently disordered oxide structures .
• Sun, Xinwei; Vøllestad, Einar & Norby, Truls (2022). Surface protonics - a tutorial.
• Norby, Truls (2022). Defects and transport in proton conducting ceramics for energy applications.
• Norby, Truls; Ma, Quanbao; Qureishy, Thomas & Uggerud, Einar (2022). Plasma-enhanced ammonia synthesis over nanoscopic Ru/CeO2.
• Norby, Truls (2022). Geometrical aspects of surface protonics.
• Norby, Truls (2022). Chemistry of high-temperature thermoelectric oxides and TEGs .
• Norby, Truls (2022). Proton ceramics for energy applications.
• Stange, Marit Synnøve Sæverud; Stefan, Elena; Dayaghi, Amir Masoud; Denonville, Christelle; Larring, Yngve & Rørvik, Per Martin [Show all 8 contributors for this article] (2021). Pulsed Laser Deposition of Electrolytes for Metal-Supported Proton-Conducting Electrolysis Cells.
• Norby, Truls (2021). New ways for protons and electrons in functional materials .
• Norby, Truls (2021). Surface protonics and its roles in synthesis and use of ammonia.
• Norby, Truls (2021). Proton ceramics - a tutorial.
• Norby, Truls; Dayaghi, Amir Masoud; Storhaug, Sjur; Chen, Henry; Haugsrud, Reidar & Stange, Marit Synnøve Sæverud [Show all 9 contributors for this article] (2021). BSZCY151020: A proton ceramic electrolyte with increased TEC for planar applications .
• Øygarden, Vegar; Mahmood, Asif; Vøllestad, Einar; Denonville, Christelle; Norby, Truls & Rørvik, Per Martin (2021). Development of electrochemical cells based on surface protonics.
• Øygarden, Vegar; Mahmood, Asif; Vøllestad, Einar; Denonville, Christelle; Norby, Truls & Rørvik, Per Martin (2021). Development of electrodes and complete electrochemical cells based on surface protonics.
• Sun, Xinwei & Norby, Truls (2021). Surface protonic conductivity in chemisorbed and physisorbed water layers in porous nanoscopic CeO2.
• Stange, Marit Synnøve Sæverud; Stefan, Elena; Denonville, Christelle; Dayaghi, Amir Masoud; Larring, Yngve & Rørvik, Per Martin [Show all 11 contributors for this article] (2021). Processing route for Metal Supported Proton Conducting Ceramic Cells.
• Norby, Truls; Kang, Xiaolan; Sun, Xinwei; Vøllestad, Einar; Gu, Jie & Han, Donglin (2021). Surface Protonics of Porous Oxide Ceramics.
• Øygarden, Vegar; Vøllestad, Einar; Denonville, Christelle; Vistad, Ørnulv Bjørnsson; Mahmood, Asif & Norby, Truls [Show all 7 contributors for this article] (2021). Development of electrodes and complete electrochemical cells based on surface protonics.
• Strandbakke, Ragnar; Balaguer, María; Carrillo, Alfonso; Wachowski, Sebastian Lech; Mielewczyk-Gryń, Aleksandra & Szpunar, Iga [Show all 13 contributors for this article] (2021). Hydration and electrochemistry of mixed conducting cobaltites.
• Strandbakke, Ragnar; Balaguer, María; Carrillo, Alfonso; Wachowski, Sebastian Lech; Mielewczyk-Gryń, Aleksandra & Szpunar, Iga [Show all 14 contributors for this article] (2021). Hydration and electrochemistry of mixed conducting cobaltites.
• Norby, Truls; Sun, Xinwei; Kang, Xiaolan; Vøllestad, Einar; Gu, Jie & Han, Donglin (2021). Surface Protonics of Porous Oxide Ceramics .
• Norby, Truls (2021). Electrode kinetics in fuel cells and electrolyzers.
• Norby, Truls Eivind (2021). Electrode kinetics in fuel cells and electrolysers. Show summary

  Fuel cells constitute the technology of choice to convert hydrogen to electricity, while electrolyzers will be a major technology for producing that hydrogen from electricity from renewable sources, notably indirect (hydroelectric, wind, wave) and direct (photovoltaic) solar energy. They are hence not directly the topic of a workshop on solar fuels, but photoelectrochemical (PEC) electrode kinetics is such a complex matter that it is useful to have electrode kinetics of fuel cells and electrolyzers as kind of reference. Both PEC and fuel cells and electrolyzers have in common that established state-of-the-art versions have aqueous liquid electrolytes, while solid-state electrolytes are of increasing interest. We will cover both, and dwell on various intermediate cases. While various charge carrying ions are in use in different ranges of temperature (O2-, CO32-, H+, OH-, H3O+), protonic electrolytes are most central to PEC and we will focus on them, with examples from proton ceramics, proton exchange membranes (PEMs), hydroxide ion conducting polymers, and surface protonic conduction. The electrode reaction comprises faradaic charge transfer over the electrolyte-electrode interface. This can be an electron transfer (redox) or – in the case of mixed ion electron conducting electrodes – ion transfer, in which case the electron transfer must take place somewhere else, e.g. on the electrode surface. The charge transfer – which is our means of driving the reaction with a voltage or recording a current in a chemically driven fuel cell – may be hindered by the supply of reactants, making adsorption and dissociation appear in the polarization resistance. In addition, diffusion in gas phase, over surfaces, and in the bulk of the electrode or electrolyte slows the reaction further and may eventually limit the current. While charge transfer takes place over the double layer capacitance of the electrolyte-electrode interface, the other processes may store reactants and products as much higher chemical capacitance, whereby the different processes have different time constants and may be separated in impedance spectroscopy. The talk will go through materials, processes, and methods, look to general principles that can be applied across systems and technologies, where possible also photoelectrochemical cells for solar hydrogen and artificial photosynthesis.

• Norby, Truls Eivind (2021). Fra forsker til grunder: Hvilken hjelp skulle jeg ønsket meg.
• Norby, Truls Eivind (2020). Ceramic proton conductors for natural gas, hydrogen, and ammonia.
• Norby, Truls Eivind (2020). Ceramic proton conductors and photoelectrochemistry for hydrogen .
• Norby, Truls Eivind (2020). Space Charge Effects at Interfaces of Proton Conducting Oxides.
• Norby, Truls Eivind (2020). Ceramic proton conductors for natural gas, hydrogen, and ammonia.
• Norby, Truls Eivind & Sun, Xinwei (2020). Protonic conduction in water and hydrogen adsorbed in porous materials.
• Strandbakke, Ragnar; Bjørheim, Tor Svendsen; Sørby, Magnus Helgerud; Szpunar, Iga; Wachowski, Sebastian Lech & Mielewczyk-Gryń, Aleksandra [Show all 10 contributors for this article] (2020). Governing principles of hydration in mixed conducting oxides.
• Liu, Xin; Risbakk, Sanne; Almeida Carvalho, Patricia; Yang, Mingyi; Backe, Paul Hoff & Bjorås, Magnar [Show all 8 contributors for this article] (2020). Hydrogenase-assisted catalysis on titania electrode oxides.
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Backe, Paul Hoff; Ruan, Qiushi; Tang, Junwang & Bjørås, Magnar [Show all 8 contributors for this article] (2020). The use of NMR to assess the activity of formate dehydrogenase biocatalysts for CO2 utilization.
• Thøgersen, Annett; Diplas, Spyridon; Michel, Kathrin; Bjørheim, Tor Svendsen; Prytz, Øystein & Norby, Truls Eivind (2020). The surface of CeO2 unravelled.
• Norby, Truls Eivind (2020). Electrodics for Protonics.
• Chen, Henry; Norby, Truls; Haugsrud, Reidar & Dayaghi, Amir Masoud (2022). Sintering Behavior and Conductivity of (Ba0.85Sr0.15)(Zr0.7Ce0.1Y0.2)O3-δ Doped with ZnO as Sintering Aid. Kjemisk Institutt, Universitetet i Oslo.
• Svee, Tord; Norby, Truls; Haugsrud, Reidar; Strandbakke, Ragnar; Thoreton, Vincent & Clar, Daniel (2021). Surface kinetics of BaGd1-xLaxCo2O6-𝛿 for use as an anode material in proton ceramic electrolyser cells. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet. Show summary

  The main topic of this thesis is the surface kinetics of BaGdxLa1-xCo2O6-δ (BGLC), a mixed ionic electronic conducting double perovskite, with operation temperatures between 400-700 °C that shows potential for use as an anode in Proton Conducting Ceramic Electrolysers (PCEC). While showing promise the material is still limited by its surface reactions, notably adsorption and dissociation. To test the variation in surface kinetics with the ratio of lanthanides on the A’-site, five compositions with differing lanthanide content was synthesised with a sol-gel synthesis path: BGLC19 (BaGd0.1La0.9Co2O6-δ), BGLC37 (BaGd0.3La0.7Co2O6-δ), BGLC55 (BaGd0.5La0.5Co2O6-δ), BGLC73 (BaGd0.7La0.3Co2O6-δ) and BGLC91 (BaGd0.9La0.1Co2O6-δ). Acceptable phase purity was determined through X-ray diffractometry (XRD), the batches sieved into four different grain size ranges, with diameters of 63-45 μm being used for all later experiments. Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis were applied to examine the morphology and determine the specific surface area of the samples. Pulse isotope exchange (PIE) and gas phase analysis (GPA) were used to examine the surface kinetics of the samples. The PIE data also allows us to extract the adsorption and incorporation energy of gas species from the total activation energy. Comparative measurements in 21% oxygen at 400 °C for BGLC19 with GPA and PIE resulted in surface exchange coefficients for oxygen of 6.8×10-5 mol m-2 s -1 (PIE) and 1.3×10-5 mol m-2 s -1 (GPA), with the difference being attributed to exchange rates in GPA being limited by gas diffusion in the chamber. An experiment was also performed with PIE on BGLC19 in 21% and 2% oxygen, resulting in surface exchange coefficients of 6.8×10-5 mol m-2 s -1 (21%) and 1.2×10-4 mol m-2 s -1 (2%) at 400 °C. The total activation energy E0 for oxygen exchange was lower in 2% oxygen (0.84 eV in 2% vs 1.1 eV in 21%), but with a slightly higher adsorption energy Eads (0.79 eV in 2% vs 0.62 eV in 21%). Measurements were also performed with PIE in 2% oxygen across compositions, with BGLC55 showing the lowest incorporation energy Einc for oxygen at 0.82 eV but with the highest E0 (0.91 eV) and Eads (0.92 eV) of the set. BGLC73 displayed the lowest values for total activation and adsorption energies at 0.62 eV (E0) and 0.69 eV (Eads). The highest surface exchange rates for oxygen were measured for BGLC19, BGLC73 and BGLC91 at over 1×10-4 mol m-2 s -1 , while the values for BGLC37 and BGLC55 were around 6×10-4 mol m-2 s -1 . 3 PIE experiments involving the exchange of water vapour were also performed on BGLC37 and BGLC91, with BGLC73 exchanging the most water up to 450 °C. With unclear data and very little to no D2O measured by the mass spectrometer, these experiments remain inconclusive.

• Køller, Egil Sperstad; Norby, Truls; Bjørheim, Tor Svendsen & Both, Kevin Gregor (2021). The Effect of Exsolved Nanoparticles on the Thermoelectric Properties of SrTiO3. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet.
• Alsgaard, Erik Erlend Pham; Norby, Truls; Haugsrud, Reidar & Bjørheim, Tor Svendsen (2021). Protonic Transport Properties of Perovskite Heterostructures. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet. Show summary

  Proton ceramic fuel cells based on an yttrium-doped barium zirconate electrolyte might pose as a viable option for future hydrogen applications. High resistances in the electrolyte however hampers the performance of the material. Therefore, a novel heterostructure engineering strategy is applied in order to investigate alternative solutions to reducing the resistances. This thesis aims to deepen our understanding of how heterostructures and their interfaces might affect the electrolyte resistances. The goal of the following approach is to circumvent proton trapping at acceptor dopant sites. A job-sharing model has been investigated where one phase “supplies” the protons while the other phase conducts them. The proton donor phase is acceptor doped and more acidic than the other phase, resulting in a net transfer of protons over to the conductive phase. The latter phase, free of trap sites and enriched in charge carriers, is then hypothesized to exhibit a conductivity increase. Modern computational methods allow for compositions to be investigated theoretically without having to perform tedious experiments. While experiments measure the actual effects of the system of interest, the results might be ambiguous as they often are a combination of several contributions. Theoretical computations on the other hand might give insight into trends, often on the atomistic scale, else impossible to separate from other effects experimentally. Combining the two methods, in depth knowledge and understanding of the system is acquirable. The model system, an alternating multi layered BaZr1-xYxO3/SrTi1-xScxO3 film was fabricated by pulsed laser deposition onto a (100) MgO substrate. The thin (60 nm) films were by X-ray diffraction confirmed to be grown epitaxially, made possible by a good lattice match between the substrate and the films. Impedance spectroscopy measurements of the BaZrO3/SrTi0.9Sc0.1O3 film showed a conductivity of 0.27 mS/cm, comparable to the conductivity of the reference BaZr0.9Y0.1O3 film (0.28 mS/cm). The activation energy of the heterostructure was measured to 0.45 eV, lower than for the reference BaZrO3 and BaZr0.9Y0.1O3 films and in the range of the proton migration activation energy. The SrTi0.9Sc0.1O3 had a larger activation energy of 0.64 eV, expected for oxide ion conduction mechanism. VII When going to dry from humid atmosphere for the BaZr1-xYxO3 containing films was a decrease in conductivity of 55 % to 65 %, attributed to a decrease in charge carrier (proton) concentrations which was further confirmed by a hydrogen isotope exchange. A slope of 0.143 was observed in the Arrhenius plot of the SrTi0.9Sc0.1O3 film, indicating that ionic defects dominate concentration-wise whilst minority holes contribute significantly to the conductivity in the measured pO2 range. First principles calculations of a BaZr0.984Y0.016O3H0.016 4 by 4 supercell showed the energy difference a at set of Y-H + distances. The trapping energy of the protons was calculated as a function of in-plane strain and was found to increase with more negative (compressive) strain. Additionally, strain in general decreases the long-range mobility of protons in the yttrium dopants because of an energy barrier, larger than or equal to the trapping energy. Removing -0.5 % of strain was found to result in an activation energy decrease, increasing the conductivity by a factor of two. The calculated trapping energy change for different levels of strain agree well with experimental activation energies from literature [1]. Comparisons of measurements between reference films and the BaZrO3/SrTi0.9Sc0.1O3 heterostructure supports the job-sharing model. By assuming that the space charge region of the BaZrO3 and SrTi0.9Sc0.1O3 does not affect the conductivity of the latter, a conductivity increase of a factor of 14 was calculated for the BaZrO3 layer of the heterostructure compared to the reference BaZrO3 film.

• Gudmundsdottir, Jonina Björg; Norby, Truls & Chatzitak, Athanasios (2021). Double Perovskite Cobaltites as Oxygen Evolution Reaction Catalysts in Electrochemical and Photoelectrochemical Water Splitting Cells. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet.
• Kang, Xiaolan; Norby, Truls & Chatzitakis, Athanasios (2021). Novel nanostructured materials for energy applications. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet. ISSN 1501-7710. 2021(2465). Show summary

  Nanomaterials and nanotechnology have been flourishing greatly over the last decades and their applications are spreading almost over all the branches of science and technology. In this work, we zoomed into the synthesis and characterization of nanostructured materials. The central focus was to manipulate the compositions, morphology and structures of nanomaterials by combining various strategies like defect engineering and exsolution. Several interesting features and properties of nanostructured materials were investigated and highlighted, including the optical, plasmonic, electronic and surface properties. This process deepened our fundamental understanding of surface protonic conduction of nanocrystalline oxides and increased our control over nanostructuring of materials in order to achieve targeted functionalities. The as-prepared nanomaterials have been applied in energy- and environment-related applications, showing improved and controllable efficiency in pollutants degradation and water (vapor) splitting in photocatalytic, (photo) electrocatalytic, as well as in a solid-state photoelectrocatalytic systems.

• Elstad, Aleksander Andestad; Norby, Truls & Sartori, Sabrina (2021). Alkali and Alkaline Earth Oxoacid Salts; Synthesis, Hydration, Stability and Electrical Conductivity. Department of Chemisty, UiO.
• Kalland, Liv-Elisif Queseth; Norby, Truls Eivind; Mohn, Chris Erik & Haugsrud, Reidar (2021). Ab-initio modelling and experimental study of order-disorder, hydration, and ionic conductivity of fluorite-related oxides. Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo. ISSN 1501-7710. 2021(2348). Show summary

  Hydrogen will play a key role in a zero-emission society, and proton (H+) conducting oxides have gained interest as solid-state electrolytes for next-generation electrochemical devices for fuel cells and electrolyzers. Understanding the effect of structure on materials functional properties is important for enhancing the performance of such electrolytes. Oxides with fluorite related crystal structures are interesting for their high oxide ion and proton (H+) conductivities, and in this work the relationship between the atomic structure and the materials properties such as ionic conductivity and hydration properties have been studied for three different oxides. They are oxygen deficient with respect to the fluorite structure and the vacant oxide ion sites can thus be ordered or disordered. Through a combination of different experimental and computational methods the nature and degree of ordering and the atomic structure have been determined, and correlated to the properties of the cations present, such as size and electronegativity. The work further focuses on whether ordering the oxide ion vacancies affects the hydration and consequently the proton conductivity. The results have led us to propose a new model for hydration of heavily doped yet disordered fluorite oxides.

• Schuler, Raphael; Fjellvåg, Helmer & Norby, Truls Eivind (2021). Oxide thermoelectrics - materials, junctions and modules. Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo. ISSN 1501-7710. 2021(2364). Show summary

  Thermoelectric materials are able to directly convert heat into electricity, which makes them predestined candidates for the recuperation of waste heat and contributing to a more efficient energy economy. They hold enormous potential for energy generation, since all thermodynamic processes lose a major portion of their energy in the form of waste heat. However, conventional thermoelectric materials are often toxic, scarce and/or expensive, and show limited high temperature stability, which currently limits their relevance for large-scale applications. Recently, oxide thermoelectric materials, composed of abundant elements have attracted increased interest, as they offer a cheaper, environmental-friendly, and high-temperature stable alternative. They are usually discovered and researched individually, and only later combined to a p-n pair in a module, which often leads to complications, like thermal mismatch or reactions. In this work the approach was taken to design a compatible pair of new thermoelectric oxides that preclude complications in advance. This novel approach is demonstrated on a model pair of iron tungstates, which show promising thermoelectric properties and an exceptional band alignment, which could prove to be key properties for future thermoelectrics.

• Andersen, Karoline Sjøen; Norby, Truls; Sartori, Sabrina & Chatzitakis, Athanasios (2020). Hydrophobic coatings for offshore PV modules: Impact of precipitation from seawater on the protective glass. Department of Chemisty, UiO.
• Morland, Bjørn Helge; Svenningsen, Gaute & Norby, Truls Eivind (2020). Corrosion in CO2 transport pipeline. Formation of corrosive phases in dense phase CO2. Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo. ISSN 1501-7710. 2020(2215). Show summary

  Carbon capture and storage is suggested as one of the solutions to reduce CO2 emissions. Material choice is an important part for the total cost of the transport system for CO2. The present work comprises investigations of corrosive situations which could occur during transport of CO2 for injection to reservoirs. As CO2 with various combinations and concentrations of impurities were tested in a systematic manner, it was clear that combinations from established CO2 transport recommendations resulted in formation of a separate aqueous phase that contained high concentrations of sulfuric and nitric acid. However, many new impurity combinations were basically inert and could be considered safe to transport in carbon steel pipelines. Altogether, the present work has identified many important aspects of corrosion and chemical reactions for CO2 transport. This results in a better understanding of the processes that leads to corrosion and is needed for the making of a CO2 specification which ensure the integrity of pipelines or ships.

• Xu, Kaiqi; Norby, Truls Eivind; Chatzitakis, Athanasios Eleftherios & Bjørheim, Tor Svendsen (2020). Artificial photosynthesis – Advanced nanomaterials and use of biocatalysts for novel photoelectrochemical cells. Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo. ISSN 1501-7710. 2020( 2254). Show summary

  The capture and storage of solar energy in chemical form by a photoelectrochemical (PEC) cell is an elegant and simple solution to the increasing energy demands and needs for chemicals and fuels from non-fossil sources. We first developed a facile fabrication method of a monolithic solid-state PEC (SSPEC) cell, which utilizes a solid-state polymer electrolyte and minimizes the distance between the two electrodes. The recent progress in understanding of surface proton conduction in porous ceramic-based electrolytes led to the idea of using the SSPEC cell for hydrogen production through water vapor splitting. The traditionally Pt-based cathode was replaced by an earth-abundant photocathode, g-C3N4, which increased the intrinsic photo-induced electrical field by a factor of three. Such a monolithic SSPEC cell working fully in the gas phase was demonstrated first time, and can play an important role for clean energy production in rural or other areas where grid infrastructure and clean water sources are limited or absent. CO2 utilization is considered a key player in a carbon-free energy economy, emphasising the importance of CO2 capture and conversion. We have successfully demonstrated how a bio-catalyst (enzyme) can be coupled with traditional chemical engineering for this purpose. To approach this, a stable, highly photo-active material - Ta3N5 nanotubes - has been synthesized and tested in a photoelectrochemical cell. It reaches close to its theoretical performance in photo-assisted water splitting. We then coupled the Ta3N5 nanotubes as the photoabsorber together with an optimised enzyme - formate dehydrogenase (FDH) - in a photoelectrochemical cell. The aim is to mimic natural photosynthesis to reduce CO2 into a valuable chemical form – formic acid. A solar-driven reduction of CO2 and water to formic acid at close to 100% faradaic efficiency has been reached.

• Olofsson, Andreas Connor & Norby, Truls Eivind (2020). An investigation of Ca3CoMnO6 as a thin-film layer on oxide thermoelectric materials. Kjemisk Institutt, Universitetet i Oslo.
• Andersen, Karoline Sjøen; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2020). Hydrophobic coatings for offshore PV modules: Impact of precipitation from seawater on the protective glass. Kjemisk Institutt, Universitetet i Oslo.
• Ormann, Brage Otto; Norby, Truls Eivind & Vines, Lasse (2020). Stable oxide p-n heterojunctions -- NiO-ZnO based transistor. Kjemisk Institutt, Universitetet i Oslo.
• James, Roystan; Norby, Truls Eivind; Vines, Lasse & Bjørheim, Tor Svendsen (2020). Electrical properties of La2CuO4 and Nd2CuO4 and their coexistent p-n heterojunction. Kjemisk Institutt, Universitetet i Oslo.
• Andreassen, Magnus Haga; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2020). Synthesis, characterization, and optimization of Cu2O photocathodes for solid-state photoelectrochemical cells. Kjemisk Institutt, Universitetet i Oslo.
• Simonsen, Stian Christopher; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2020). Nafion®-Ceramic Composite Electrolytes for Proton Exchange Membrane Fuel Cells at Elevated Temperatures. Kjemisk Institutt, Universitetet i Oslo.
• Andersen, Håkon; Norby, Truls Eivind & Strandbakke, Ragnar (2020). Functional Properties and Electrochemical Performance of New Positrode Materials for Proton Ceramic Electrochemical Cells. Kjemisk Institutt, Universitetet i Oslo. Show summary

  Proton Ceramic Electrochemical Cells (PCECs) exhibit high efficiency at lower temperatures due to the low activation energy ofproton transport. PCECs havealso obtained a great interest for its fuel utilisation, which result in a higher operating cell voltage and efficiency. However, the development of efficient commercial PCECs has been held back by the lack ofanefficient electrode at the oxygen steam side, also known as positrode.BaGd0.8La0.2Co2O6-δ (BGLC82) has shown to be a state of the art positrode, with Mixed Proton and Electronic Conductivity (MPEC). By using BGLC82 as a backbone in developing new and efficient electrode materials, the primary object of this thesis is to study the functional properties of selected doped BGLC82 materials, with their focus as positrodematerials for PCECs. BGLC82 was 10 % doped with the chosen materials zinc, titanium and zirconia (BaGd0.8La0.2Co1.8X0.2O6-δX=Zn, Ti, Zr). The BGLC82 compositionswere synthesised by solid-state reaction (SSR). BGLC82 Ti and Zn showed to obtain single phases, whereasBGLC82: Zr exhibit a secondary phase of BaZrO3. To try to obtain a single phase of BGLC82: Zr sol-gel (SG) synthesis was used. BGLC82: Zr still exhibited the same secondary phase obtained for SSR, but with a lower amount. This implies that the solubility of Zr in BGLC82 was exceeded.BGLC82 Ti and Zn were tested for proton uptake by Thermogravimetric Analysis (TGA)at 300 –500 °C. The measurementsshowed that BGLC82: Ti exhibitsa higher proton uptake than BGLC82, whereas BGLC82: Zn obtain lower proton uptake than BGLC82. This implies that the donor dopant stabilises the protonic defectsin the BGLC82 structure, dueto the basisety of the cation. For the experimental setup, small pellets of the BGLC82 composites were placed on top of a BaZr0.7Ce0.2Y0.1O3-δ(BZCY72) at the same time and held in place by a spring load. To obtain the best contact between the electrodes and the electrolyte, the surfaces in contact were polished. Platinumwas used as counter and reference electrode,placed on the opposite side of the BGLC82 composite electrodes.

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