Effect of promoters on the structures and properties of the RuB/γ-Al2O3 catalyst

Effect of promoters (Co, Fe, Sn, Zn) on structures, properties and catalytic performance of RuB/gamma-Al2O3 catalyst was studied using in situ XRD, TEM, H-2-TPD, XPS and liquid-phase hydrogenation of ethyl lactate to 1,2-propanediol (PDO). It was found that incorporation of Sn or Fe improved the dispersion and thermal stability of RuB. The electron density of Ru and the strength and capacity of H-2 adsorption on the RuB catalyst were also enhanced by the incorporation of Sri or Fe. The incorporation of Co or Zn led to a significant decrease in H, adsorption capacity of the RuB catalyst. Both ethyl lactate conversion and selectivity to 1,2-PDO increased with the incorporation of Sn or Fe. The ethyl lactate conversion decreased sharply with the incorporation of Zn or Co accompanied by an increase in selectivity to 1,2-PDO and lactic acid. The effect of promoters on reaction behavior was discussed on the basis of the characterizations. (c) 2004 Elsevier B.V. All rights reserved.