In this study, calcium-rich resource minerals such as brushite, tricalcium phosphate (TCP), and hydroxyapatite were tested as catalysts for the methanolysis of alkaline solutions of NaBH₄ to generate hydrogen H₂. The synthesis of calcium phosphate compounds was characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The hydrogen generation rate with the TCP catalyst (15,214 mL min⁻¹ g⁻¹) was higher than with the hydroxyapatite catalyst (12,437 mL min⁻¹ g⁻¹) and brushite catalyst (6210 mL min⁻¹ g⁻¹) for the methanolysis of 250 mg NaBH₄ at 298 K using 25 mg of catalyst. The impact of TCP weight on hydrogen generation was studied. The methanolysis reaction led to a higher hydrogen volume generation over time with an increase in the weight of the TCP catalyst at a temperature of 308 K. The calculated activation energy for NaBH₄ hydrolysis with the TCP catalyst was 23.944 kJ mol⁻¹, suggesting the high catalytic activity of TCP. The values of enthalpy (ΔH) and entropy (ΔS) were calculated, and the results showed that ΔH was 21.28 kJ mol⁻¹ and ΔS was −93.096 J·mol⁻¹. ΔH was positive, meaning that the reaction was endothermic, and the negative ΔS meant a decrease in the disorder of the methanolysis reaction. The stability of the catalysis was tested in successive methanolysis tests. The catalyst’s efficiency decreased to 89% after four cycles.

Cyclohexylammonium hexaisothiocyanatonickelate(II) dihydrate, (C₆H₁₁NH₃)₄[Ni(NCS)₆]·2H₂O, was synthesized, for the first time, by a four-step method in a yield of 95%. The compound was fully characterized by elemental microanalysis, Fourier transform infrared (FTIR), ultraviolet-visible-near infrared (UV-Vis-NIR), and nuclear magnetic resonance (NMR) spectroscopy and thermogravimetry. A single crystal X-ray diffraction (SXRD) gave the monoclinic space group P2₁/c with a = 15.8179 (5) Å, b = 10.6222 (3) Å, c = 13.8751 (4) Å, β = 109.362 (1)°, V = 2199.45 (11) ų, Z = 2 (T = 293 K) for this novel hybrid organic–inorganic compound. The title compound was employed as a single-source precursor for the synthesis of mesoporous, high surface area nickel oxide (53 Å; 452 m²/g) and nickel sulfide (46 Å; 220 m²/g) via pyrolysis under air at 550 °C or helium atmosphere at 500 °C, respectively. X-ray powder diffraction (XRPD) demonstrated the nanocrystalline nature of both NiO and NiS with an average crystallite size of 16 and 54 nm, respectively. Scanning electron microscope (SEM) indicated the formation of agglomerated, quasi-spherical particles of nickel oxide and agglomerated flake-like structures of nickel sulfide. The high surface area, porosity, and nanocrystallinity of both NiO and NiS, obtained via this approach, are promising for a wide spectrum of applications.