dc.rights.license | CC-BY-NC-ND | |
dc.contributor.advisor | Jong, K.P. de | |
dc.contributor.advisor | Krans, N.A. | |
dc.contributor.author | Uunen, D.L. van | |
dc.date.accessioned | 2021-09-06T18:00:20Z | |
dc.date.available | 2021-09-06T18:00:20Z | |
dc.date.issued | 2019 | |
dc.identifier.uri | https://studenttheses.uu.nl/handle/20.500.12932/796 | |
dc.description.abstract | The effect of the support material on particle growth of supported nanoparticles is not yet fully
understood. In this research colloidal synthesis, followed by the attachment was used to prepare
a well-defi?ned model catalyst suited to investigate the growth of Fe/SiO2 and Fe/TiO2 during the
Fischer-Tropsch to ole?ns (FTO) reaction. 7 nm iron oxide nanoparticles (Fe-NP) with a narrow
particle size distribution were synthesized using the heating-up method and subsequently attached to
SiO2 and TiO2 support materials. Despite the difference in Hamaker constants between SiO2 and TiO2,
a similar Fe-loading per surface area was obtained. The catalytic performance in FTO was evaluated
after activation in H2 and CO. In general the activity of the supported Fe-NP was comparable to
reference catalysts prepared by impregnation, however Fe-NP/P25 was less active. TEM and STEM
analysis of the used catalyst revealed tremendous particle growth of up to 100 nm for Fe-NP/TiO2
while SiO2 supported Fe-NP remained stable after 100h on stream. Further experiment showed that
growth already occurs during the activation in H2 at temperatures above 325°C. A semi-quantitative
EDX analysis revealed the presence of large amount (80%) iron species on the TiO2 support.
Additionally, Mossbauer spectroscopy results indicated the presence of amorphous Fe3TiO3 or Fe2+
surface species for reduced Fe-NP/TiO2. Base on these ?ndings, a surface species assisted Ostwald
ripening process was proposed as growth mechanism for TiO2 supported Fe catalysts. | |
dc.description.sponsorship | Utrecht University | |
dc.format.extent | 16465798 | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | |
dc.title | Particle growth of iron oxide nanoparticles on SiO2 and TiO2 supports | |
dc.type.content | Master Thesis | |
dc.rights.accessrights | Open Access | |
dc.subject.keywords | Fischer-Tropsch synthesis, colloidal iron oxide, particle growth, titania and silica supports | |
dc.subject.courseuu | Nanomaterials Science | |