Hydrogen release through catalyzed methanolysis of solid sodium borohydride - Archive ouverte HAL
Article Dans Une Revue Energy Année : 2010

Hydrogen release through catalyzed methanolysis of solid sodium borohydride

Résumé

Methanolysis of sodium borohydride (NaBH4) is a way of recovering the hydrogen stored in the hydride. Though the reaction is spontaneous, it can be accelerated by virtue of Co-TiO2 or Ru-TiO2 catalysts. Under our experimental conditions, Co-TiO2 shows high catalytic performances, higher than those of Ru-TiO2. Hydrogen generation rates of 144 to 644 L(H-2) min(-1) g(-1)(Co) were measured as the Co content was decreased. The kinetic parameters of the catalyzed reaction were determined. The Co-TiO2- catalyzed methanolysis follows a power law, i.e. r(20) k center dot[NaBH4](1.3)center dot[CH3OH](0.9) with k = 1.8 x 10(-2) s(-1). The Langmuir-Hinshelwood bimolecular mechanism accounts for the kinetics. The apparent activation energy was found to be 20.4 kJ mol(-1) whereas that of the catalyzed hydrolysis was 49.4 kJ mol(-1). Indeed, the catalyzed methanolysis was compared to the catalyzed hydrolysis as well as the catalyzed ethanolysis. For instance, it was remarked that water in methanol has a detrimental effect on the H-2 release kinetics. In parallel, the gravimetric hydrogen density of the system NaBH4-CH3OH has been optimized. Under our experimental conditions, it was found that the highest capacity that can be achieved is 3.4 wt%.

Dates et versions

hal-00552870 , version 1 (06-01-2011)

Identifiants

Citer

J. Hannauer, U. B. Demirci, G. Pastor, C. Geantet, J. M. Null Herrmann, et al.. Hydrogen release through catalyzed methanolysis of solid sodium borohydride. Energy, 2010, 3 (11), pp.1796-1803. ⟨10.1039/c0ee00023j⟩. ⟨hal-00552870⟩
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