Cooperative effects in ternary Cu-Ni-Fe catalysts lead to enhanced alkene selectivity in alkyne hydrogenation.

A new generation of heterogeneous Cu-Ni-Fe catalysts with appropriate metal ratios displayed outstanding alkene selectivity in the gas-phase hydrogenation of propyne (S(C(3)H(6)) up to 100%) and ethyne (S(C(2)H(4)) up to 80%). The design was accomplished by orchestrating key functions in the catalyst: copper is the base hydrogenation metal, nickel increases the hydrogen coverage to minimize oligomerization, and iron acts as structural promoter. In addition to the largely improved alkene selectivity compared to that of the commonly applied Pd catalysts, the ternary Cu-Ni-Fe catalysts promise substantial process advantages, since they do not require CO feeding as selectivity enhancer and they yield high alkene selectivity in a broad window of H(2)/alkyne ratios. The ternary system requires higher operating temperatures compared to those for palladium.