Blar i NTNU Open på forfatter "Tsakoumis, Nikolaos"
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Capturing metal-support interactions in situ during the reduction of a Re promoted Co/γ-Al2O3 catalyst
Tsakoumis, Nikolaos; Johnsen, Rune E.; van Beek, Wouter; Rønning, Magnus; Rytter, Erling; Holmen, Anders (Journal article; Peer reviewed, 2016)The reduction of a Re promoted Co/γ-Al2O3 catalyst was monitored in situ by synchrotron X-ray powder diffraction (XRPD) under H2 environment. Whole powder pattern analysis revealed a non-linear expansion of the unit cell ... -
Evaluation of Reoxidation Thresholds for γ-Al2O3-Supported Cobalt Catalysts under Fischer - Tropsch Synthesis Conditions
Tsakoumis, Nikolaos; Walmsley, John; Rønning, Magnus; van Beek, Wouter; Rytter, Erling; Holmen, Anders (Journal article; Peer reviewed, 2017)Size-dependent phenomena at the nanoscale influence many applications, notably in the science of heterogeneous catalysis. In cobalt-based Fischer–Tropsch synthesis (FTS), the size of Co nanoparticles (NPs) dictates to a ... -
Hydrophobic Catalyst Support Surfaces by Silylation of γ-Alumina for Co/Re Fischer-Tropsch Synthesis
Rytter, Erling; Salman, Ata ul Rauf; Tsakoumis, Nikolaos; Myrstad, Rune; Yang, Jia; Lögdberg, Sara; Holmen, Anders; Rønning, Magnus (Journal article; Peer reviewed, 2018)Eight different silanes with chloro or methoxy active ligands have been examined to modify the surface of a standard γ-alumina support to investigate the effect of surface acidity and hydrophobicity in Fischer-Tropsch ... -
Multivariate curve resolution applied to in situ X-ray absorption spectroscopy data: An efficient tool for data processing and analysis
Voronov, Alexey; Urakawa, Atsushi; van Beek, Wouter; Tsakoumis, Nikolaos; Emerich, Hermann; Rønning, Magnus (Journal article; Peer reviewed, 2014)Large datasets containing many spectra commonly associated with in situ or operando experiments call for new data treatment strategies as conventional scan by scan data analysis methods have become a time-consuming bottleneck. ... -
Structure-performance relationships on Co based Fischer–Tropsch synthesis catalysts: The more defect free the better
Tsakoumis, Nikolaos; Patanou, Eleni; Lögdberg, Sara; Johnsen, Rune; Myrstad, Rune; Van Beek, Wouter; Rytter, Erling; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)Understanding and utilizing structure–performance relationships in catalytic nanomaterials is the epitome of catalysis science. Knowledge at the atomic level can potentially allow rational design of more selective and ... -
Surface Modified γ-Alumina Supports For Cobalt Fischer-Tropsch Catalysts
Salman, Ata ul Rauf (Master thesis, 2015)Fischer-Tropsch synthesis over cobalt based catalysts is an important route for the conversion of syngas, derived from natural gas, to liquid fuels. Fischer-Tropsch performance of cobalt catalysts depends on a number of ... -
The impact of sequential H2-CO-H2 activation treatment on the structure and performance of cobalt based catalysts for the Fischer-Tropsch synthesis
Patanou, Eleni; Tsakoumis, Nikolaos; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)Different activation protocols were applied to a promoted Re/Co/γ-Al2O3 catalyst for Fischer-Tropsch synthesis. The activation included treatment in either pure H2 or a sequence of Reduction (H2) – Carburization (CO) – ... -
Water as key to activity and selectivity in Co Fischer-Tropsch synthesis: γ-alumina based structure-performance relationships
Rytter, Erling; Borg, Øyvind; Tsakoumis, Nikolaos; Holmen, Anders (Journal article; Peer reviewed, 2018)Thirteen γ-alumina supports with different pore sizes and pore size distributions have been impregnated with cobalt and rhenium. The catalysts were tested for Fischer-Tropsch synthesis (FTS) under dry and enhanced water ... -
X-ray absorption, X-ray diffraction and electron microscopy study of spent cobalt based catalyst in semi-commercial scale Fischer-Tropsch synthesis
Tsakoumis, Nikolaos; Dehghan-Niri, Roya; Rønning, Magnus; Walmsley, John; Borg, Øyvind; Rytter, Erling; Holmen, Anders (Peer reviewed; Journal article, 2014)Calcined, reduced and spent Co-Re/γ-Al2O3 catalysts for Fischer–Tropsch synthesis (FTS) were characterized and compared. Co-K-edge and Re-LIII-edge X-ray absorption near edge structure (XANES), X-ray powder diffraction ...