<scp>Effects of Rare Earth and Alkali Promoters on Distribution Profile and Properties of Spherical Shaped</scp> γ‐ <scp> Al ₂ O ₃ Supported </scp> Ni <scp>Catalysts</scp>

This study investigates the effects of rare-earth (La and Ce) and alkali (Mg and K) promoters on the distribution profile and properties of spherical γ-Al₂O₃ supported Ni catalysts. The catalysts were synthesized via sequential wet impregnation, targeting 10 wt.% Ni, with individual and co-promotion of promoters. The distribution profiles of Ni within the spherical support revealed that promoter addition caused a NiO concentration gradient along the spherical catalysts. Characterization techniques such as X-ray diffraction (XRD), BET (Brunauer-Emmet-Teller), scanning electron microscope & energy dispersive X-ray spectroscopy (SEM-EDX), scanning/transmission electron microscope (S/TEM), and temperature programmed reduction (TPR) demonstrated that promoter addition significantly influenced the distribution profile, particle size, and reducibility of NiO. According to the obtained results, catalysts co-promoted with La and Mg achieved a homogeneous distribution profile and the lowest reduction temperature, indicating enhanced Ni reducibility and potentially improved catalytic performance. These findings highlight the critical role of promoters as well as co-promotion in modifying the active metal distribution and properties of Ni/γ-Al₂O₃ catalysts.