ABSTRACT
Chemical Research Center, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri út 59-67 Hungary; gobolos@chemres.hu
Abstract Butyl acetate was hydrogenolyzed to butanol over different RePt/Al2O3 and Re modified SnPt/Al2O3 naphtha reforming type catalysts both in a conventional autoclave and a high throughput (HT) slurry phase reactor (AMTEC-SPR16). Catalytic tests performed in a single autoclave revealed that Re is a crucial ingredient for high conversion (95 %) and selectivity (90 %) at 235 °C and 6 MPa. The addition of Re to the SnPt/Al2O3 catalyst significantly improved its activity. The specific activity showed a maximum at a Re content of 0.8 wt. %. In the HT activity tests, the reaction order for butyl acetate and the apparent activation energy was close to zero and 115 kJ/mole, respectively. TPR of RePt catalysts indicated the presence of the oxide precursors of separate Pt clusters, RePt alloy phase and Re ions stabilized by the support. It is proposed that in the activation of the carbonyl group "M1n+-M20" ensembles (M1 = Re, Sn; M2 = Pt, Re, RePt or SnPt alloy) are involved. Introduction The catalytic hydrogenolysis of esters to two alcohols was first described by Folkers and Adkins in 1931 and has since assumed considerable industrial importance [1]. Conventionally the reaction is carried out in the liquid phase using a copper chromite catalyst at 10 MPa H2 pressure and ~ 250 °C [2,3]. Due to the concern for the toxicity of Cr nowadays, CuO-ZnO/Al2O3 catalysts are used [4]. Supported SnRu [5], or SnRh [6] catalysts with high metal loading have gained much scientific interest in the transformation of less reactive carbonyl compounds such as amides, esters and acids to the corresponding products. It has been reported that in Cu-[7] and Ru-based [8] catalysts the mutual presence of both ionic and metallic species is required to activate the carbonyl group and the hydrogen, respectively.
