Hydroxyapatite supported cobalt catalysts for hydrogen generation

Justyn Wayne Jaworski, Sunghwa Cho, Yeoungyong Kim, Jong Hwa Jung, Hyo Sang Jeon, Byoung Koun Min, Ki Young Kwon

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The controlled generation of H2 from storage materials by using an efficient catalytic support is a highly sought after technology; however, the majority of successes utilize expensive materials considered unfeasible. In our report on the creation of a novel, durable, and inexpensive catalytic support material for hydrogen generation, we examine a critical surface modification of hydroxyapatite (HAP) with cobalt ions to provide the necessary catalytic transition metal for the fast hydrolysis of the hydrogen storage material, sodium borohydride (NaBH4). By altering the morphology and composition of the HAP crystal supports, we revealed novel methods for enhancing the hydrogen generation rates. Particularly, lowering the Ca composition during synthesis of the HAP crystals afforded a Ca deficient HAP capable of exhibiting a higher surface coverage of cobalt, thereby eliciting faster hydrolysis reaction rates in comparison with the amorphous HAP control having the characteristic Ca content for HAP. A more significant increase in hydrogen generation was observed when using single crystal HAP in comparison with amorphous and calcium deficient HAP supports. Despite the smaller surface area of the hydrothermally prepared single crystal HAP, it provided significantly faster hydrogen generation. Each of the HAP supports exhibit repeatability with catalytic efficiency decreasing by approximately 25% over 3weeks upon repeated daily exposure to solutions of the hydrogen storage material NaBH4. Through these experiments, we proved that altering the composition and morphology of cobalt ion exchanged HAP supports can offers a useful means for increasing the rate of controlled hydrogen generation.

Original languageEnglish
Pages (from-to)401-408
Number of pages8
JournalJournal of Colloid and Interface Science
Volume394
Issue number1
DOIs
Publication statusPublished - 2013 Mar 15

Keywords

  • Calcium deficient
  • Cobalt
  • Hydrogen generation
  • Hydroxyapatite support
  • Ion exchange

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

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  • Cite this

    Jaworski, J. W., Cho, S., Kim, Y., Jung, J. H., Jeon, H. S., Min, B. K., & Kwon, K. Y. (2013). Hydroxyapatite supported cobalt catalysts for hydrogen generation. Journal of Colloid and Interface Science, 394(1), 401-408. https://doi.org/10.1016/j.jcis.2012.11.036