SBA-15锚定的钌杂多酸催化剂的合成及其催化正十六烷氧化

Ru-polyoxometalates immobilized on SBA-15 as heterogeneous catalysts for n-hexadecane oxidation

利用(3-氨丙基)三乙氧基硅烷(apts)将钌金属杂多酸[X2W20O70(RuY)2]10-(其中,X为锑或铋,Y为苯或对异丙基苯甲烷)固定在介孔的SBA-15上可得到一系列性能优良的SBA-15锚定的钌杂多酸催化剂。采用XRD、N2吸附-脱附实验和FT-IR红外光谱对此类催化剂进行表征,并检测其对正十六烷氧化的催化性能。结果表明,以空气为氧化剂,在无任何溶剂的条件下,该锚定的钌杂多酸催化剂遵循传统的自由基自氧化机理,将正十六烷烃氧化成各种醇类和酮类,显示出优良的催化性能。因此,这类多相催化剂对环境友好的烷烃氧化反应具有较高的应用价值。

The selective oxidation of alkanes as a green process remains a challenging task because of inactive C--H oxidation. Heterogeneous Ru-polyoxometalates catalysts were synthesized by using organo- ruthenium supported heteropolytungstates,[ Sb2 W20 O70 （ RuC6 H6 ） 2]^10^-, [ Bi2 W20 O70 （ RuC6 H6 ）2 ]^10^-, [Sb2 W20 O70 （ RuC10 H14 ） 2 ] 10^-, and [ Bi2 W20 O70 （ RuC10 H14 ） 2 ] ^10- anchored on 3-aminopropyltriethoxysilane （apts）-modified mesoporous SBA-15. The catalysts were characterized by X-ray diffraction （XRD）, N2- adsorption measurements and Fourier transform infrared reflectance （FT-IR） spectroscopy. The results of these analyses indicated that these catalysts had high surface area, uniform hexagonal channels which were similar to those of SBA-15, and organo-ruthenium supported heteropolytungstates were highly dispersed in the pores of the modified silica. The heterogeneous Ru-polyoxometalates catalysts were used as catalysts for the solvent-free aerobic oxidation of n-hexadecane to alcohols and ketones by using air as the oxidant under ambient conditions. They exhibited exceptionally high catalytic performance through a classical freeradical autoxidation mechanism. Therefore, the catalysts demonstrated the prospect of this type of heterogeneous catalyst for practical applications.