A new metal-decorated carbon catalyst for dehydrogenation of complex hydride hydrogen storage materials

Sean S.Y. Lin, Jun Yang, Harold H. Kung

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In recent years, many new solid-state hydrides with a high hydrogen capacity that meet DOE requirement (> 7.5 wt.% H 2) have been synthesized as promising on-board hydrogen storage materials. In these hydrides, however, only a small fraction of hydrogen can be released at a desired on-board operating temperature (<85°C) due to a slow dehydrogenation kinetics of the hydrides. It has been discovered that the kinetics can be improved by adding transition metal catalysts to form metal-hydride intermediates that facilitate hydrogen transportation and desorption. Nevertheless, identification of such catalyst for various hydrides is a challenging task because the catalytic effect is component-specific. Here we report a new form of catalyst for dehydrogenation of complex hydride, using a well-studied NaAlH 4 as a test case. Dehydrogenation of NaAlH 4 can be greatly facilitated by activated carbon catalysts. The catalytic function can be further enhanced by decorating the carbon with Co, Ni, or Cu nanoparticles. The decomposition temperature was lowered by as much as 100°C using a 3 wt.% Co or Ni-decorated activated carbon, comparable to a Ti-based catalyst, which were the most effective among the metals tested. The catalytic effect is likely due to a combination of hydrogen spillover effect, high contact area between carbon and the hydride, and confinement of the hydride as nano-sized domains in the pores of the carbon matrix. The catalysts were also effective in facilitating rehydrogenation of NaAlH 4 under moderate pressure (75.8 bar H 2) and low temperature (120°C), when no rehydrogenation would occur without the catalyst. The fact that this new catalyst system is not specific to any hydride offers many potential applications.

Original languageEnglish
Title of host publication11AIChE - 2011 AIChE Annual Meeting, Conference Proceedings
Publication statusPublished - Dec 1 2011
Event2011 AIChE Annual Meeting, 11AIChE - Minneapolis, MN, United States
Duration: Oct 16 2011Oct 21 2011

Publication series

Name11AIChE - 2011 AIChE Annual Meeting, Conference Proceedings

Other

Other2011 AIChE Annual Meeting, 11AIChE
CountryUnited States
CityMinneapolis, MN
Period10/16/1110/21/11

ASJC Scopus subject areas

  • Chemical Engineering(all)

Fingerprint Dive into the research topics of 'A new metal-decorated carbon catalyst for dehydrogenation of complex hydride hydrogen storage materials'. Together they form a unique fingerprint.

  • Cite this

    Lin, S. S. Y., Yang, J., & Kung, H. H. (2011). A new metal-decorated carbon catalyst for dehydrogenation of complex hydride hydrogen storage materials. In 11AIChE - 2011 AIChE Annual Meeting, Conference Proceedings (11AIChE - 2011 AIChE Annual Meeting, Conference Proceedings).