Fe改性对Ru/Al_2O_3催化剂的马来酸二甲酯加氢性能影响

以Al2O3为载体,采用吸附-沉淀法制备一系列Ru-Fe/Al2O3催化剂,并进行了H2-TPR、XRD及XPS表征。以马来酸二甲酯(DMM)催化加氢合成丁二酸二甲酯(DMS)为探针反应,考察了Fe的加入对Ru/Al2O3催化性能的影响。评价结果表明,当Fe/Ru原子比小于2时,催化剂活性变化不大;但Fe/Ru原子比大于或等于2时,催化剂活性明显增加;与Ru/Al2O3催化剂相比,Fe的加入改善了催化剂的高温氧化还原处理稳定性。以甲醇为溶剂,在70℃、1.0 MPa压力、600 r/min转速下,Ru-Fe/Al2O3催化DMM的转化率与生成DMS的选择性均接近100%。XPS和H2-TPR表征结果表明,Ru-Fe/Al2O3中Fe与Ru产生较强的相互作用,促进Ru的分散且调变了Ru的电子特性。

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.