Chemistry of supported palladium nanoparticles during methane oxidation
Artikel i vetenskaplig tidskrift, 2015
Time-resolved in situ energy-dispersive X-ray absorption spectroscopy and mass spectrometry are used to correlate changes in chemical state of alumina and ceria supported palladium nanoparticles with changes in activity and selectivity for methane oxidation. Specifically, modulation excitation spectroscopy experiments are carried out by periodically cycling between net-reducing and net-oxidizing reaction conditions. The XANES and EXAFS data show that the palladium nanoparticles are readily bulk oxidized when exposed to oxygen, forming a PdO-like phase, and reduced back to a reduced (metal) phase when oxygen is removed from the feed. The difference between the two support materials is most noticeable at the switches between net-oxidizing and net-reducing reaction conditions. Here, a brief reduction in conversion is observed for the alumina supported catalyst, but for the ceria this reduction in conversion is minor or not observed at all. This difference is attributed to differences in the oxidation kinetics and the oxygen storage capability of ceria.
XAFS
homogeneous catalysis
modulation excitation
methane
in situ
Författare
Johan Nilsson
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
Per-Anders Carlsson
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
Sheedeh Fouladvand
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
Natalia Mihaela Martin
Kompetenscentrum katalys (KCK)
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Johan Gustafsson
Lunds Universitet
Mark Newton
European Synchrotron Radiation Facility
Edvin Lundgren
Lunds Universitet
Henrik Grönbeck
Kompetenscentrum katalys (KCK)
Chalmers, Teknisk fysik, Kemisk fysik
Magnus Skoglundh
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
ACS Catalysis
2155-5435 (eISSN)
Vol. 5 4 2481-2489Drivkrafter
Hållbar utveckling
Styrkeområden
Nanovetenskap och nanoteknik
Transport
Energi
Materialvetenskap
Ämneskategorier (SSIF 2011)
Fysikalisk kemi
Kemiska processer
Atom- och molekylfysik och optik
Fundament
Grundläggande vetenskaper
DOI
10.1021/cs502036d