Browsing NTNU Open by Author "Svenum, Ingeborg-Helene"
Now showing items 1-20 of 24
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Carbon Formation Mechanisms on Co Surfaces: A DFT Study
Jacobsen, Ida Emilie Malde (Master thesis, 2021)Fisher-Tropsch syntesen (FTS) er en katalytisk prosess hvor syngas omdannes til vann og hydrokarboner som for eksempel lange kjeder av alkaner, alkener og oksygenater. Interessen for FTS har økt på grunn av den økende ... -
Core-Shell Nanostructures of Graphene-Wrapped CdS Nanoparticles and TiO2 (CdS@G@TiO2): The Role of Graphene in Enhanced Photocatalytic H2 Generation
Zubair, Muhammad; Svenum, Ingeborg-Helene; Rønning, Magnus; Yang, Jia (Peer reviewed; Journal article, 2020)Aiming to achieve enhanced photocatalytic activity and stability toward the generation of H2 from water, we have synthesized noble metal-free core-shell nanoparticles of graphene (G)-wrapped CdS and TiO2 (CdS@G@TiO2) by a ... -
Core-shell particles of C-doped CdS and graphene: A noble metal-free approach for efficient photocatalytic H2 generation
Zubair, Muhammad; Vanhaecke, Estelle Marie M.; Svenum, Ingeborg-Helene; Rønning, Magnus; Yang, Jia (Journal article; Peer reviewed, 2020)To achieve efficient photocatalytic H2 generation from water using earth-abundant and cost-effective materials, a simple synthesis method for carbon-doped CdS particles wrapped with graphene (C-doped CdS@G) is reported. ... -
Effect of trace potassium on hydrogen adsorption and dissociation on hcp cobalt: A density functional theory study
Chen, Qingjun; Svenum, Ingeborg-Helene; Gavrilovic, Ljubisa; Chen, De; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)Trace amounts of potassium (K) have a significant influence on the activity and selectivity of cobalt-based catalysts in Fischer–Tropsch synthesis (FTS), in which hydrogen adsorption and dissociation is one of the initial ... -
Effect of trace potassium on hydrogen adsorption and dissociation on hcp cobalt: A density functional theory study
Chen, Qingjun; Svenum, Ingeborg-Helene; Gavrilovic, Ljubisa; Chen, De; Blekkan, Edd Anders (Journal article; Peer reviewed, 2019)Trace amounts of potassium (K) have a significant influence on the activity and selectivity of cobalt-based catalysts in Fischer–Tropsch synthesis (FTS), in which hydrogen adsorption and dissociation is one of the initial ... -
Effects of K adsorption on the CO-induced restructuring of Co(11-20)
Strømsheim, Marie Døvre; Svenum, Ingeborg-Helene; Farstad, Mari Helene; Li, Zheshen; Gavrilovic, Ljubisa; Guo, Xiaoyang; Lervold, Stine; Borg, Anne; Venvik, Hilde Johnsen (Journal article; Peer reviewed, 2017)The location of potassium (K) on Cobalt (Co) and its effect on adsorption and adsorption-induced surface restructuring is important for understanding the deactivation of Co Fischer-Tropsch catalysts and the nature of the ... -
Effects of sulphur on a Co/Mn-based catalyst for Fischer-Tropsch reactions
Enger, Bjørn Christian; Walmsley, John; Svenum, Ingeborg-Helene; Tolchard, Julian R; Yang, Jia; Myrstad, Rune; Gjervan, Torbjørn; Khan, Asad Ahmad; Mutairi-Al, Abdulkarim; Karim, Khalid (Journal article; Peer reviewed, 2018)The long term effect of up to 10 ppm H2S was studied for Fischer–Tropsch conversion of syngas by catalytic testing at 240 °C, 5 bar, H2/CO = 2.1 and GHSV = 2400 Nml/gcat h. Sulphur was dosed after ~ 300 or ~ 1000 h time ... -
Facile synthesis approach for core-shell TiO2–CdS nanoparticles for enhanced photocatalytic H2 generation from water
Zubair, Muhammad; Svenum, Ingeborg-Helene; Rønning, Magnus; Yang, Jia (Journal article; Peer reviewed, 2018)With the ambition to design a cost-effective and highly stable photocatalyst with improved photocatalytic activity towards H2 generation by water splitting, herein we report a two-step facile synthesis approach for core-shell ... -
Interaction of hydrogen with flat (0001) and corrugated (11–20) and (10–12) cobalt surfaces: Insights from experiment and theory
Weststrate, Kees-Jan; Mahmoodinia, Mehdi; Farstad, Mari Helene; Svenum, Ingeborg-Helene; Strømsheim, Marie Døvre; Niemantsverdriet, Hans; Venvik, Hilde Johnsen (Journal article; Peer reviewed, 2019)Cobalt catalysts are used on a commercial scale to produce synthetic fuels via the Fischer-Tropsch synthesis process. As adsorbed hydrogen atoms are involved in many of the elementary reaction steps that occur on the ... -
Interactions of Functional Groups with Surfaces
Svenum, Ingeborg-Helene (Doktoravhandlinger ved NTNU, 1503-8181; 2009:128, Doctoral thesis, 2009)The adsorption of atoms and molecules is a key step in a wide range of technologically important areas including catalysis, adhesion, corrosion, electrochemistry and microelectronics. Investigations of well-defined systems ... -
Investigations of Pd3Au(100) as a catalytic model system
Hådem, Gaute Osaland (Master thesis, 2018)Catalysts are defined as materials that lowers the activation energy of a reaction, without being consumed. In heterogeneous catalysis they are commonly transitions metals which have been refined to small particles using ... -
Investigations of PdAu membranes and model systems for production of pure hydrogen
Sørvik, Linn Cecilie (Master thesis, 2015)Hydrogen production from carbon-containing energy sources can capture the CO2 on site, and therefore reduce the contribution to global warming. The only emission when energy is produced through a fuel cell is H2O. Another ... -
Mn promoted Co catalysts for Fischer-Tropsch production of light olefins – An experimental and theoretical study
Pedersen, Eirik Østbye; Svenum, Ingeborg-Helene; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)Three different CoMn/gamma-Al2O3 catalysts were prepared by the incipient wetness impregnation route and compared to a Co/gamma-Al2O3 catalyst. The effect of co-impregnation vs. sequential impregnation as well as the order ... -
Mn promotion effects in Co based Fischer-Tropsch production of light olefins
Pedersen, Eirik Østbye (Doctoral theses at NTNU;2018:180, Doctoral thesis, 2018)In this work, Mn promotion of γ-Al2O3 supported Co catalysts was investigated for the purpose of producing light olefins via the Fischer-Tropsch synthesis process. CoMn/γ-Al2O3 catalysts were prepared by the incipient ... -
New insight to the effects of heat treatment in air on the permeation properties of thin Pd77%Ag23% membranes
Vicinanza, Nicla; Svenum, Ingeborg-Helene; Peters, Thijs; Bredesen, Rune; Venvik, Hilde Johnsen (Journal article; Peer reviewed, 2018)Sputtered Pd77%Ag23% membranes of thickness 2.2–8.5 µm were subjected to a three-step heat treatment in air (HTA) to investigate the relation between thickness and the reported beneficial effects of HTA on hydrogen transport. ... -
Pd3Ag(111) as a Model System for Hydrogen Separation Membranes: Combined Effects of CO Adsorption and Surface Termination on the Activation of Molecular Hydrogen
Svenum, Ingeborg-Helene; Herron, Jeffrey A.; Mavrikakis, Manos; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2020)The co-adsorption of hydrogen and carbon monoxide on Pd3Ag(111) alloy surfaces has been studied as a model system for Pd-Ag alloys in membrane and catalysis applications using periodic density functional theory calculations ... -
Pd3Ag(111) as a Model System for Hydrogen Separation Membranes: Combined Effects of CO Adsorption and Surface Termination on the Activation of Molecular Hydrogen
Svenum, Ingeborg-Helene; Herron, Jeffrey A.; Mavrikakis, Manos; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2020)The co-adsorption of hydrogen and carbon monoxide on Pd3Ag(111) alloy surfaces has been studied as a model system for Pd-Ag alloys in membrane and catalysis applications using periodic density functional theory calculations ... -
Potassium adsorption behavior on hcp cobalt as model systems for the Fischer–Tropsch synthesis: a density functional theory study
Chen, Qingjun; Svenum, Ingeborg-Helene; Qi, Yanying; Gavrilovic, Ljubisa; Chen, De; Holmen, Anders; Blekkan, Edd Anders (Journal article; Peer reviewed, 2017)Potassium (K), an important impurity in syngas from biomass, can have a large influence on the activity and selectivity of cobalt-based Fischer–Tropsch synthesis (FTS) catalysts in Biomass to Liquids (BTL) processes. In ... -
Properties and application of PdCu membranes for hydrogen separation.
Lindgren, Camilla (Master thesis, 2014)Hydrogen is one of the most important chemicals used in the industry today. The energy in hydrogen molecules can be converted into electric energy in fuel cells, and hydrogen is thus considered an energy carrier for the ... -
Segregation dynamics of a Pd-Ag surface during CO oxidation investigated by NAP-XPS
Strømsheim, Marie Døvre; Svenum, Ingeborg-Helene; Mahmoodinia, Mehdi; Boix, Virgínia; Knudsen, Jan; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2021)The dynamic changes in composition in the near-surface region of a Pd75%Ag25%(100) single crystal were monitored using near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during CO oxidation under oxygen rich ...