Abstract
This study investigates the hydrogenation of cyclopentadiene and 1-hexene over skeletal nickel catalysts modified with various metallic additives. The results demonstrate the high catalytic activity of skeletal nickel in promoting the migration of the –C=C– bond during the hydrogenation of 1-hexene. It was found that the addition of Fe, Pd, Sn, and Ag enhances the migration coefficient (Kmigr), while Ti, Mo, and Ti–Mo exert little to no influence on this process. The catalytic performance in the hydrogenation of cyclopentadiene is strongly affected by the nature of the modifying elements incorporated into the initial alloy. Additives such as Cu, Zn, Mo–Cu, Bi, and Mo significantly improve both the activity (W = 73–158 cm³/min·g Ni) and selectivity (Ksel = 0.93–0.98) of the reaction, facilitating the selective conversion of cyclopentadiene to cyclopentene. In contrast, Ti, Sn, and Cr–Cu additives do not substantially enhance either the activity or selectivity of the catalyst. The study highlights that the electronic and structural effects introduced by the modifying elements play a crucial role in determining the catalytic behavior of skeletal nickel systems. These findings provide valuable insights into the design of efficient nickel-based catalysts for selective hydrogenation processes and underline the potential of multi-component catalytic systems in optimizing reaction pathways. Overall, the research expands the understanding of structure–activity relationships in skeletal metal catalysts and demonstrates how tailored additive selection can improve both hydrogenation efficiency and product selectivity.