Structure-function relationship for CO 2 methanation over ceria supported Rh and Ni catalysts under atmospheric pressure conditions

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Abstract

In situ structural and chemical state characterization of Rh/CeO 2 and Ni/CeO 2 catalysts during atmospheric pressure CO 2 methanation has been performed by a combined array of time-resolved analytical techniques including ambient-pressure X-ray photoelectron spectroscopy, high-energy X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy. The ceria phase is partially reduced during the CO 2 methanation and in particular Ce 3+ species seem to facilitate activation of CO 2 molecules. The activated CO 2 molecules then react with atomic hydrogen provided from H 2 dissociation on Rh and Ni sites to form formate species. For the most active catalyst (Rh/CeO 2 ), transmission electron microscopy measurements show that the Rh nanoparticles are small (average 4 nm, but with a long tail towards smaller particles) due to a strong interaction between Rh particles and the ceria phase. In contrast, larger nanoparticles were observed for the Ni/CeO 2 catalyst (average 6 nm, with no crystallites below 5 nm found), suggesting a weaker interaction with the ceria phase. The higher selectivity towards methane of Rh/CeO 2 is proposed to be due to the stronger metal-support interaction.

Detaljer

Författare
  • Natalia M. Martin
  • Felix Hemmingsson
  • Andreas Schaefer
  • Martin Ek
  • Lindsay R. Merte
  • Uta Hejral
  • Johan Gustafson
  • Magnus Skoglundh
  • Ann Christin Dippel
  • Olof Gutowski
  • Matthias Bauer
  • Per Anders Carlsson
Enheter & grupper
Externa organisationer
  • Chalmers University of Technology
  • Malmö University
  • German Electron Synchrotron (DESY)
  • University of Paderborn
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Kemiska processer
  • Biokatalys och enzymteknik
Originalspråkengelska
Sidor (från-till)1644-1653
Antal sidor10
TidskriftCatalysis Science and Technology
Volym9
Utgivningsnummer7
StatusPublished - 2019
PublikationskategoriForskning
Peer review utfördJa