Selective Hydrogenation of Phenylacetylene Isoprene Mixtures on Multicomponent Skeletal Nickel Catalysts

This study investigates the selective hydrogenation of phenylacetylene-isoprene mixtures using multicomponent skeletal nickel (Ni) catalysts, with a focus on the influence of alloy composition on catalytic performance.X-ray diffraction analysis revealed that Ni-Al-Zn, Ni-Al-Mo-Cr, and Ni-Al-Ti-Mo alloys predominantly consist of finely dispersed nickel phases, whereas Ni-Cr-Cu and Ni-Ti-Cu systems additionally form the NiAl intermetallic phase.The specific surface area and hydrogen adsorption capacity of the catalysts were strongly dependent on modifying additives: Mn, Mo-Cr, Ti-Mo, and Cr-Cu enhanced these properties (115-146 m/g Ni and 69-105 cm/g Ni, respectively), whereas Zn and Pb additives led to reduced performance.Catalytic testing demonstrated preferential hydrogenation of phenylacetylene over isoprene, driven by differences in adsorption affinity.The hydrogenation activity varied significantly with additive composition-Zn, Cu, Pb, Mo-Cu, Ta, Bi, and Ag increased reaction rates (W = 153-286 cm/ming Ni), while Mn, Fe, and Ti-Cu suppressed activity (W = 56-75 cm/ming Ni).The results of studies of hydrogenation of binary mixtures of phenylacetylene-isoprene indicate the advantage of phenylacetylene in selective hydrogenation on multicomponent skeletal nickel catalysts, primarily due to the significant difference in adsorption coefficients (Vf/Vi=31-130).