不同载体负载的铂催化剂在丙酮酸乙酯不对称氢化反应中的活性及其铂流失率比较

以介孔树脂材料FDU-14和介孔碳材料CMK-3为载体制备了两种负载型铂催化剂,用N2气吸附、X射线衍射及CO化学吸附等手段对这两种催化剂进行了表征,并将这两种不同的负载型铂催化剂在丙酮酸乙酯不对称氢化反应中的催化性能及其铂流失率与商品化Pt/Al2O3催化剂进行了比较.研究结果表明,尽管Pt/Al2O3催化剂的初始活性和光学选择性均较高,然而相同反应条件下乙酸溶剂中Pt/FDU-14和Pt/CMK-3催化剂的铂流失率比Pt/Al2O3催化剂的低.通过对催化剂进行CO吸附原位傅里叶变换红外漫反射光谱(DRIFTS)表征,从载体的不同表面电子性质角度解释了不同载体负载的铂催化剂在丙酮酸乙酯不对称氢化反应中的活性和铂流失率的差异.

Comparison of Catalytic Performance and Stability for Pt Catalysts Supported on Different Materials in Chiral Hydrogenation of Ethyl Pyruvate

5.0%(mass fraction) Pt catalysts supported on periodic mesoporous resols(FDU-14) and ordered mesoporous carbon materials(CMK-3) were prepared using a wet impregnation method, respectively. The ca-talytic performances of Pt/FDU-14 and Pt/CMK-3 catalysts in the asymmetric hydrogenation of ethyl pyruvate were compared with the commercial Pt/Al2O3 catalyst. Although the commercial Pt/Al2O3 catalyst affords the highest initial activity and enantioselectivity, the Pt/FDU-14 and Pt/CMK-3 catalysts are superior to Pt/Al2O3 in immobilization of platinum under the same conditions. Based on the chemical nature of different supports, the difference in the catalytic performance and stability of three supported Pt catalysts was interpreted for the enantioselective hydrogenation of ethyl pyruvate.