Catalytic performance of Fe-modified Ru/Al₂O₃ in the hydrogenation of dimethyl maleate

Fe-modified Ru/Al₂O₃ (Ru-Fe/Al₂O₃) catalysts were prepared by adsorption-precipitation (AP) method with alumina as the support and characterized by H₂-TPR, XRD and XPS; the effect of Fe modification on the catalytic performance of Ru-Fe/Al₂O₃ was investigated in the selective hydrogenation of dimethyl meleate (DMM) to dimethyl succinate (DMS). The results indicated that through the modification with a Fe/Ru atomic ratio above 2, the catalytic performance of Ru-Fe/Al₂O₃ and its stability towards high temperature oxidation-reduction treatment is obviously enhanced. Under 70℃, 1.0 MPa and with a stirring speed of 600 r/min, the conversion of DMM and the selectivity to DMS were both nearly 100%. The XPS and H₂-TPR results suggest that the promoting effect of Fe on Ru-Fe/Al₂O₃ may be ascribed to an increase of Ru dispersion as well as a change in Ru electronic state through the modification with Fe.