Metal hydrides as bi-functional catalysts for hydrogen generation and oxidation in reversible MH-air fuel cells.

• Two kinds of metal hydride alloys as the bi-functional catalyst concept for hydrogen generation and oxidation in hydrogen-diffusion electrodes were investigated. The AB5-type hydride electrode shows much higher catalytic activities than the Zr-based AB2-type hydride electrode. However, the activity of Zr-based hydride electrodes can be improved only after removal of zirconium oxides on surface by a 1.0 M HF solution. The experiments demonstrated that the both metal-hydride hydrogen-diffusion electrodes for cycles of hydrogen generation (12 h) and oxidation (12 h) had good stability under the current densities of 100 and 50 mA/cm2, respectively. The results also showed that small amounts of oxygen below 500 ppm and moisture up to 145,000 ppm in the hydrogen gas have little effect on the activity. It indicated that the hydride alloys as the non-noble-metal bi-functional catalysts in a reversible MH-air fuel cell have potential applications.

Ämnesord

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Nyckelord

Metal hydride

Catalyst

Hydrogen

Gas-diffusion electrode

Air-MH fuel cell

Inorganic chemistry

Oorganisk kemi

Materials Chemistry

materialkemi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)