Method development for copper dispersion evaluation and copper-based catalysts characterization
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
N2O chemisorption technique for copper dispersion determination was developed and optimized for accurate and reproducible results. With this technique, the bulk oxidation of pre-reduced catalyst can be prevented by N2O decomposition at low temperature (30oC). Only surface copper atoms are oxidized. The amount of freshly oxidized surface coppers is determined from H2-back-titration of fixed oxygen.The impact of temperature and time of exposure during oxidation was studied. Measurements made at higher temperature (60oC) resulted in overestimation of copper dispersion due to oxygen diffusion into the bulk and sub-layers. Much longer exposure time may also have an impact on copper dispersion estimation.For accurate results and good precision, it is recommended to work under mild conditions (isothermal oxidation at 30oC for 45 min.The developed method was successfully applied to fresh and spent catalyst. As expected, the copper dispersion for fresh catalyst was significantly higher than copper dispersion for spent catalyst.
Place, publisher, year, edition, pages
2013. , 57 p.
UPTEC K, ISSN 1650-8297 ; 13007
N2O chemisorption, heterogenous catalysis, copper dispersion, copper-based catalysts characterization
Other Chemical Engineering
IdentifiersURN: urn:nbn:se:uu:diva-206922OAI: oai:DiVA.org:uu-206922DiVA: diva2:646219
The Dow Chemical Company
Master Programme in Chemical Engineering
2013-05-07, 16:34 (English)
Launay, Hélène, Dr.
Larsson, Karin, Prof.Spångberg, Daniel