Effect of the carbon support graphitization on the activity and thermal stability of Ru-Ba-Cs/C ammonia decomposition catalysts

Kristina N. Iost, Vadim A. Borisov, Victor L. Temerev, Nadezhda S. Smirnova, Yury V. Surovikin, Mikhail V. Trenikhin, Aleksey B. Arbuzov, Tatyana I. Gulyaeva, Dmitry A. Shlyapin, Pavel G. Tsyrulnikov, Aleksey A. Vedyagin

Research output: Contribution to journalArticle

Abstract

Three-component Ru-Ba-Cs/C catalysts supported on the graphite-like carbonaceous composite material Sibunit were synthesized. The effects of the graphitization procedure of the support (thermal treatment at 1900 °C) on the phase composition and the distribution of the components were studied. The catalytic activity in the ammonia decomposition reaction and the thermal stability of the samples were examined in comparison with the untreated support. The samples were characterized by Raman spectroscopy, XAFS, TEM, and XRD methods. It was found that in the case of untreated support, Ru presents in the form of both the metallic and partially oxidized fine particles. The graphitization of the carbon support facilitates the formation of large, well-crystallized metal particles. Barium in both samples was found to be unevenly distributed and presented mainly as large particles of carbonate. Cesium-containing species were not detected. The effect of the support graphitization on the thermal stability is comparable with catalyst modification by Ba and Cs. At the same time, combination of these effects noticeably increases the efficiency of the catalyst. Thus, the non-promoted Ru catalyst deposited on the untreated support decomposes 107 g of NH 3 per 1 g of the lost carbon. Modification of the catalyst with Ba and Cs allows one to increase this value up to 498 g of NH 3 , while graphitization of the support and application of the combined approach were shown to give 910 and 1577 g, correspondingly.

Original languageEnglish
JournalReaction Kinetics, Mechanisms and Catalysis
DOIs
Publication statusPublished - 1 Jan 2019

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Keywords

  • Ammonia decomposition
  • Carbon support
  • Characterization
  • Graphitization
  • Thermal stability
  • Three-component catalysts

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry

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