Hydrogenation of adipic acid to 1,6-hexanediol by supported bimetallic Ir-Re catalyst

Abstract

A series of supported Ir-Re catalysts have been synthesized and used for the hydrogenation of adipic acid to 1,6-hexanediol. The influences of supporting materials and the Ir/Re atomic ratio on the catalytic performances have been studied. Results suggested that Ir-Re supported on carbon materials and alumina had appropriate acid sites and better activity for the hydrogenation of adipic acid. Compared to the monometallic catalysts, synergistic interaction was generated and electrons were delivered from Ir to Re. The uniform distribution of metal particles in the Ir-Re catalysts and the well restrained H2-spillover effect facilitated the transformation of adipic acid and the selective production of 1,6-hexanediol. The selectivity of 1,6-hexanediol was 59% with complete conversion of adipic acid at 180 °C in 10 MPa H2 after reaction for 16 h. After four times of reaction, the selectivity of 1,6-hexanediol only decreased about 4%.