Sulfur resistance and activity of Pd-Ni bimetallic catalysts for Styrene Hydrogenation

M. JULIANA MACCARRONE; MARIANA BUSTO; JUAN BADANO; NICOLÁS R. CARRARA; MÓNICA E. QUIROGA; CAROLINA P. BETTI; CECILIA R. LEDERHOS; CARLOS R. VERA

Beijing

Congreso; 16th International Congress on Catalysis (ICC 16); 2016

Bimetallic PdNiN and NiNPd catalysts were the most active during the poison-free selective hydrogenation of styrene. A higher concentration of Pdδ- species would be responsible for the higher activity of these catalysts. The PdNiCl and NiClPd catalysts had the highest values of the superficial Cl/Pd atomic ratio and were also the most sulfur resistant. Pd oxychlorinated species (Pdδ+) probably prevented the adsorption of thiophene both by a steric hindrance effect (big size of oxychlorinated species) and an electronic one (high electronegativity of Cl). The NiClPd catalyst was more sulfur resistant than the PdNiCl one. This is likely due to a higher amount of exposed Pdδ+ species and the absence of Ni0 on NiClPd. Both effects would promote a weak adsorption of thiophene and an increase of the concentration of the most active sites.