Enhanced ammonia dehydrogenation over Ru/La(x)-Al2O3 (x=0-50 mol%): Structural and electronic effects of La doping

Dan Bi Chung, Hyo Young Kim, Mina Jeon, Dae Hyung Lee, Hyun S. Park, Sun Hee Choi, SukWoo Nam, Seong Chul Jang, Jung Han Park, Kwan Young Lee, Chang Won Yoon

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Ru (1.0 wt% loaded)-based catalysts supported on La(x)-Al2O3 (x = 0, 1, 5, 10, and 50 mol%) were synthesized and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and temperature programmed reduction (TPR). The as-prepared La(x)-Al2O3 materials were found to have increased amounts of the LaAlO3 phase as the La doping level (x) increased from 0 to 50 mol%. In addition to metal-to-support interactions between Ru and Al2O3, the newly formed LaAlO3 phase in the Ru catalysts was proposed to interact strongly with Ru active sites based on the XRD, H2-TPR and XPS results. The Ru/La(x)-Al2O3 catalysts were active for the dehydrogenation of ammonia, and among them, the Ru/La(10)-Al2O3 and Ru/La(50)-Al2O3 (or Ru/LaAlO3) catalysts exhibited superior performance with >96% conversions of ammonia at 550 °C. When an increased Ru content (2.0 wt%) was impregnated onto La(10)-Al2O3, the dehydrogenation activity was significantly improved with nearly 100% conversion (>95%) of ammonia at 500 °C. This catalyst further displayed an enhanced thermal stability towards ammonia decomposition with the GHSVNH3 of 10,000 mL/gcat h at 550 °C for >120 h. The incorporated element La is thought to play an important role in enhancing metal-support interaction, ultimately facilitating ammonia dehydrogenation even at low temperatures.

Original languageEnglish
JournalInternational Journal of Hydrogen Energy
DOIs
Publication statusAccepted/In press - 2016 Apr 7

Keywords

  • Ammonia
  • Dehydrogenation
  • Hydrogen storage
  • La doped alumina
  • LaAlO
  • Ru

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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    Chung, D. B., Kim, H. Y., Jeon, M., Lee, D. H., Park, H. S., Choi, S. H., Nam, S., Jang, S. C., Park, J. H., Lee, K. Y., & Yoon, C. W. (Accepted/In press). Enhanced ammonia dehydrogenation over Ru/La(x)-Al2O3 (x=0-50 mol%): Structural and electronic effects of La doping. International Journal of Hydrogen Energy. https://doi.org/10.1016/j.ijhydene.2016.08.020