Hydrogenation of Naphthalene and Tetralin in the Presence of CO over Various Supported Metal Catalysts

Abstract

Hydrogenation of naphthalene and tetralin in the presence of CO was studied over alumina-supported Co, Ni, Ru, Rh, Pd and Pt catalysts. In the presence of CO, naphthalene was hydrogenated selectively without CO hydrogenation over Pd/Al₂O₃, whereas both naphthalene and CO were hydrogenated over Co/Al₂O₃, Ni/Al₂O₃, Ru/Al₂O₃ and Rh/Al₂O₃. The relative activity of six supported metals was dependent on the presence or absence of CO. Rh/Al₂O₃ showed very low activity for hydrogenation of naphthalene and tetralin with 2%CO–H₂, while it showed the highest activity for hydrogenation with pure hydrogen. In contrast, Pd/Al₂O₃ showed the highest activity for naphthalene and tetralin hydrogenation in the presence of CO. From FTIR measurements of adsorbed CO, the high activity for naphthalene and tetralin hydrogenation over Pd/Al₂O₃ in the presence of CO was correlated with desorption of CO (>ca. 1950 cm⁻¹) adsorbed on coordinatively unsaturated sites.