Selective Hydrogenation of the C≡C to С=С Bond on Fe-Containing Catalysts

Abstract

Supported monometallic Fe/SiO₂ and bimetallic Fe–Cu/SiO₂ catalysts were synthesized by incipient wetness impregnation. The synthesized catalytic systems were studied in selective hydrogenation of phenyl-acetylene with molecular hydrogen under mild reaction conditions (H₂ pressure 1.3 MPa, 80–110°C). The catalytic properties of monometallic samples depend on the conditions of thermal treatment. The best results on the selectivity of styrene formation (78%) at complete conversion of phenylacetylene were obtained on the reduced sample, in which iron was in the metal state. The modification of the iron oxide phase with copper (0.4 wt %) makes it possible to exclude the stage of reduction of FeO_x to Fe⁰ in hydrogen at high temperatures and to retain high catalytic activity and attain styrene selectivity of 78%.