Martelli, Pascal Caputo, Riccarda Remhof, Arndt Mauron, Philippe Borgschulte, Andreas Züttel, Andreas 2010-03-26 We investigate the stability and hydrogen desorption of NaBH₄. Dynamic pcT (pressure, concentration, and temperature) measurements under constant hydrogen flows are used to determine thermodynamic parameters of reaction. From the van’t Hoff equation the enthalpy and entropy of reaction, −108 ± 3 kJ mol⁻¹ of H₂ and 133 ± 3 J K⁻¹ mol⁻¹ of H₂ released, are obtained, respectively. This corresponds to a decomposition temperature of <i>T</i>_dec = 534 ± 10 °C at 1 bar of H₂. The decomposition thereby occurs in one step; i.e., only one plateau is visible in the pressure composition isotherms. Elemental Na is identified as the major solid component in the residue by X-ray diffraction. The experimental results are discussed on the basis of theoretical calculations using the density functional theory approach. Starting from the optimized structure of the cubic α-phase of NaBH₄, we discuss possible decomposition routes involving elemental Na and B as well as Na−H and Na−B binary compounds as residual products. application/pdf https://folia.unifr.ch/global/documents/301619 https://folia.unifr.ch/documents/301619/files/zue_sdn.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/jp909341z info:eu-repo/semantics/openAccess License undefined The Journal of Physical Chemistry C. - 2010, vol. 114, no. 15, p. 7173-7177 info:eu-repo/classification/udc/53 Stability and decomposition of NaBH₄. http://purl.org/coar/resource_type/c_6501