Details

Autor(en) / Beteiligte

• Carney, C.S.
• Chinn, R.E.
• Doğan, Ö.N.
• Gao, M.C.

Titel

Isothermal decomposition kinetics of nickel (II) hydroxide powder

Ist Teil von

• Journal of alloys and compounds, 2015-09, Vol.644 (C), p.968-974

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •A first order random nucleation model was proposed for the decomposition of nickel hydroxide.•Trapped lattice product water greatly suppressed high conversion reaction rates.•Annealing experiments of the Ni–Ni(OH)2–NiO phase triangle yielded only two phases: Ni and NiO.•This Ni–Ni(OH)2–NiO phase triangle in the Ni-rich corner of the Ni–O–H system was confirmed. Nickel (II) hydroxide powder was investigated by thermogravimetry for isothermal decomposition kinetics and verification of the Ni–O–H ternary phase diagram at low temperatures. The activation energy and frequency factor were measured as Ea=134kJ/mol and A=1.27×1010s−1, respectively. The validity of the first-order random nucleation model was confirmed, as opposed to diffusion and or moving-boundary models. The dependence of TGA results on specimen size was noted. The Ni–Ni(OH)2–NiO phase triangle was confirmed. Accordingly, a thermodynamic description of the system was established in the Ni-rich corner, and the isotherm at room temperature is calculated.