Selective hydrogenation of 1,3-butadiene over Pd and Pd–Sn catalysts supported on different phases of alumina

The gas phase selective hydrogenation of 1,3-butadiene was studied over Pd and Pd–Sn supported on mixed phase θ/α-(MA) and pure α-alumina (AA). The catalysts were characterized by XRD, XPS, TEM, and FTIR spectroscopy of adsorbed CO. A remarkable improvement in terms of activity and selectivity in the selective hydrogenation of 1,3-butadiene was achieved over Pd–Sn on the mixed phase alumina support in which butane formation and isomerization of 1-butene were suppressed. Nevertheless, Pd–Sn/AA showed much lower activity than Pd–Sn/MA due to lower metal dispersion.