Density functional theory analysis of methanation reaction of CO 2 on Ru nanoparticle supported on TiO2 (1 0 1)

Satoshi Akamaru, Tomomi Shimazaki, Momoji Kubo, Takayuki Abe

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)

Abstract

The methanation reaction of CO2 on a Ru nanoparticle supported on TiO2 catalyst has been investigated by density functional theory (DFT) using the generalized gradient approximation with periodic boundary conditions. Two plausible reaction paths were found for the transformation of CO2 to CH4 on TiO2-supported Ru nanoparticles. The origin of the high activity of the catalyst is discussed based on the overall reaction energy diagram obtained from DFT calculations. The CO 2 is readily and stably adsorbed on Ru cluster at moderate temperature as compared with that on bulk Ru surface. It is due to the difference of the Ru structure between the Ru nanoparticle and the bulk Ru surface. The elementary reactions of the hydrogenation of adsorbed CO and of the production of CH4 are possible to become the rate-determining steps over the methanation reaction, because these two reactions have a higher potential energy barrier than that of other elementary reactions in the overall reaction path. These potential energy barriers for the hydrogenation of CO and the production of CH4 on TiO2-supported Ru nanoparticles were lower than those on bulk Ru surface, which explains the high activity of the Ru nanoparticle-loaded TiO2 catalyst. The lowering of these potential energy barriers can be caused by weak charge transfer between Ru atoms and adsorbed species on the TiO2-supported Ru nanoparticles. As the results, the catalytic activity of the Ru nanoparticles supported on TiO 2 catalyst is characterized by the structure of Ru nanoparticles and by the weak charge transfer between Ru atoms and adsorbed species.

Original languageEnglish
Pages (from-to)405-411
Number of pages7
JournalApplied Catalysis A: General
Volume470
DOIs
Publication statusPublished - 2014 Jan 30

Keywords

  • CO methanation
  • Density functional theory
  • Nanoparticle
  • Ru/TiO

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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