The effects of various catalysts on the hydrogen release and uptake characteristics of LiA1H4 and NaA1H4

Keywords

Hydrogen -- Storage, Ball milling process

Abstract

The effects of various catalysts on the hydrogen release characteristics of LiAl!Li and NaAlfu were studied. The catalysts were incorporated by a dry preparation technique consisting of ball milling of LiAlfu or NaAlfu and titanium, aluminum, iron, nickel, vanadium, and carbon black -dopant mixtures. The dopants for LiAlfu included TiCh, TiC14, TiH2, TiA13, ThAl, AlCh, TiCh x 1/3 AlCh, FeCh, elemental titanium, elemental aluminum, elemental iron, elemental nickel, elemental vanadium and carbon black. The dopants for NaAlfu were TiCh, TiA13, TiJAl, elemental titanium, and elemental aluminum. Dehydriding/rehydriding properties were characterized by using differential scanning calorimetry coupled with pressure measurement, and x-ray diffraction. Different results were obtained for LiAlfu purchased from different vendors, so the effects of impurities on decomposition temperature in commercially available and purified LiAlfu were also studied. Ball milling in the absence of the catalyst was found to decrease the release temperature of hydrogen release. Doping LiAl!Li with Ti3Al, TiA13 and elemental aluminum additionally reduced temperature required for hydrogen release. That effect was not observed for mixtures with NaAlfu. The addition of TiCh to LiAlfu and NaAlfu and TiC4 to LiAlfu eliminated the first step of hydrogen evolution and significantly lowered hydrogen capacity. The LiAlfu doped with TiCh x 1/3 AlCh showed hydrogen uptake, indicating that catalyst provided for reversible hydrogen release. 11

Notes

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Graduation Date

2004

Semester

Spring

Advisor

Hampton, Michael D.

Degree

Master of Science (M.S.)

College

College of Arts and Sciences

Department

Chemistry

Format

PDF

Pages

65 p.

Language

English

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Identifier

LD1772.F96T45 2004 no.148

Subjects

Arts and Sciences -- Dissertations, Academic; Dissertations, Academic -- Arts and Sciences

Accessibility Status

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