Blar i SINTEF Open på forfatter "Venvik, Hilde Johnsen"
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Activity and segregation behavior of Pd75%Ag25%(1 1 1) during CO oxidation – An in situ NAP-XPS investigation
Svenum, Ingeborg-Helene; Strømsheim, Marie D.; Knudsen, Jan; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2022)The surface reactivity during CO oxidation over Pd(1 1 1) and Pd75%Ag25%(1 1 1) single crystals has been investigated using near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) under excess oxygen conditions ... -
Catalyst Deactivation During One-Step Dimethyl Ether Synthesis from Synthesis Gas
Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2017)Catalysts for direct synthesis of dimethyl ether (DME) from synthesis gas should essentially contain two functions, i.e., methanol synthesis and methanol dehydration. In the present work, the deactivation of both functions ... -
Deactivation of Co-Based Fischer−Tropsch Catalyst by Aerosol Deposition of Potassium Salts
Gavrilovic, Ljubisa; Brandin, Jan; Holmen, Anders; Venvik, Hilde Johnsen; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)A 20%Co/0.5%Re/γAl2O3 Fischer−Tropsch catalyst was poisoned by four potassium salts (KNO3, K2SO4, KCl, and K2CO3) using the aerosol deposition technique, depositing up to 3500 ppm K as solid particles. Standard characterization ... -
Direct dimethyl ether synthesis from synthesis gas: The influence of methanol dehydration on methanol synthesis reaction
Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2016)Direct dimethyl ether (DME) synthesis from synthesis gas is studied with regard to potential effects of methanol dehydration on methanol formation and copper-based catalyst performance. For this, the influence of the ... -
The effect of aerosol-deposited ash components on a cobalt-based Fischer–Tropsch catalyst
Gavrilovic, Ljubisa; Brandin, Jan; Holmen, Anders; Venvik, Hilde Johnsen; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2019)The effect of ash salts on Co-based Fisher–Tropsch catalysts was studied using an aerosol deposition technique. The major elements in the ash were found to be K, S and Cl. The ash was deposited on a calcined catalyst as ... -
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, 2018)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 metal dusting relevant exposures of alloy 601 surfaces on carbon formation and oxide development
Guo, Xiaoyang; Vanhaecke, Estelle Marie M.; Vullum, Per Erik; Ma, Jianyu; Panditha Vidana, Daham Sanjaya Gunawardana; Walmsley, John; Chen, De; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2020)Ni and Fe are excellent catalysts for carbon formation, and industrial alloys are therefore susceptible to metal dusting corrosion; a costly issue in e.g. synthesis gas manufacture. The objective of this work is to better ... -
Fischer-Tropsch synthesis—Investigation of the deactivation of a Co catalyst by exposure to aerosol particles of potassium salt
Gavrilovic, Ljubisa; Brandin, Jan; Holmen, Anders; Venvik, Hilde Johnsen; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)The influence of potassium species on a Co based Fischer-Tropsch catalyst was investigated using an aerosol deposition technique. This way of poisoning the catalyst was chosen to simulate the actual potassium behaviour ... -
Inhibition of metal dusting corrosion on Fe-based alloy by combined near surface severe plastic deformation (NS-SPD) and thermochemical treatment
Guo, Xiaoyang; Vullum, Per Erik; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2021)Combined NS-SPD and thermochemical treatment has been used to improve the metal dusting corrosion resistance of Incoloy 800. After testing under infinite carbon activity for 20−100 h, carbon was not found in the NS-SPD ... -
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 (Peer reviewed; Journal article, 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 ... -
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 (Peer reviewed; Journal article, 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. ... -
Partial oxidation of methanol to formaldehyde in an annular reactor
Lervold, Stine; Lødeng, Rune; Yang, Jia; Skjelstad, Johan; Bingen, Kristin; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2021)A structured reactor with annular configuration was applied for studying methanol oxidation to formaldehyde over silver. By eliminating gas phase reactions, high formaldehyde selectivity (93–97%) was obtained at low methanol ... -
Pd/CeO2 catalysts as powder in a fixed-bed reactor and as coating in a stacked foil microreactor for the methanol synthesis
Phan, Xuyen Kim; Walmsley, John Charles; Bakhtiary Davijany, Hamidreza; Myrstad, Rune; Pfeifer, Peter; Venvik, Hilde Johnsen; Holmen, Anders (Peer reviewed; Journal article, 2016)Pd/CeO2 as a catalyst for methanol synthesis has been studied in a microreactor consisting of 14 structured foils in a fixed-bed laboratory reactor. Methanol synthesis was carried out at 80 bar and 300 °C with a syngas ... -
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 ... -
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 ... -
Thickness dependent effects of solubility and surface phenomena on the hydrogen transport properties of sputtered Pd77%Ag23% thin film membranes
Vicinanza, Nicla; Svenum, Ingeborg-Helene; Næss, Live Nova; Peters, Thijs; Bredesen, Rune; Borg, Anne; Venvik, Hilde Johnsen (Peer reviewed; Journal article, 2015)The hydrogen solubility and permeation in Pd77%Ag23% membranes have been determined as a function of temperature and membrane thickness. Unexpectedly, the solubility of hydrogen is found to systematically increase as the ... -
Water–Gas Shift Activity of Pt Catalysts Prepared by Different Methods
Bjørkan, Hilde; Rønning, Magnus; Venvik, Hilde Johnsen; Johannessen, Tue; Holmen, Anders (Peer reviewed; Journal article, 2020)Platinum supported on ceria and zirconia was prepared through different preparation methods: Coprecipitation (CP), spray drying (SD), and flame spray pyrolysis (FSP). The catalysts were characterized by XRD, TPR, N2 ...