Ni-rich layered oxides, i.e., LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) and LiNiO₂ (LNO), were prepared using the two-step calcination procedure. The samples obtained at different calcination temperatures (750–950 °C for the NMC622 and 650–850 °C for the LNO cathode materials) were characterized using nitrogen physisorption, PXRD, SEM and DLS methods. The correlation of the calcination temperature, structural properties and electrochemical performance of the studied Ni-rich layered cathode materials was thoroughly investigated and discussed. It was determined that the optimal calcination temperature is dependent on the chemical composition of the cathode materials. With increasing nickel content, the optimal calcination temperature shifts towards lower temperatures. The NMC-900 calcined at 900 °C and the LNO-700 calcined at 700 °C showed the most favorable electrochemical performances. Despite their well-ordered structure, the materials calcined at higher temperatures were characterized by a stronger sintering effect, adverse particle growth, and higher Ni²⁺/Li⁺ cation mixing, thus deteriorating their electrochemical properties. The importance of a careful selection of the heat treatment (calcination) temperature for each individual cathode material was emphasized.

Co supported on mixed MgO–La ₂ O ₃ oxides as efficient and stable catalysts for ammonia synthesis.

Ammonia synthesis was performed over a barium-promoted cobalt catalyst supported on magnesium–lanthanum mixed oxide. The rate of NH₃ formation over this catalyst was about 3.5 times higher than that over the unpromoted catalyst at 9 MPa and 400 °C. Furthermore, no sign of thermal deactivation was observed during long-term overheating at 600 °C for 360 h. The results of physicochemical studies, including XRPD, DRIFTS, H₂-TPD, CO₂-TPD, N_ads + H₂ TPSR and kinetic analysis, revealed that the addition of Ba promoter increased the surface basicity of the catalyst and modified the adsorption properties of the Co surface towards H₂ and NH₃. The decreased adsorption strength of the corresponding sites towards hydrogen and ammonia resulted in greater availability of active sites in the Ba-promoted cobalt catalyst. These characteristics are considered to have a profound effect on the performance of this catalyst in NH₃ synthesis.