Heterogeneous transfer hydrogenation over mesoporous SBA-15 co-modified by anionic sulfonate and cationic Ru(III) complex
摘要:
Via ion-pair electrostatic interactions with sulfonate anions, the phosphine-ligated Ru(III) complex cations of [(RuCl4)-Cl-III(L)(2)](+) (L = 1-butyl-2-(diphenylphosphino)-3-methylimidazolium) were successfully immobilized into a sulfonated SBA-15 framework, leading to the formation of the cationic Ru(III) complex and anionic sulfonate co-modified SBA-15 material (referred to as Ru-SO3-SBA-15). This material was characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), N-2 adsorption-desorption isotherms, FT-IR, and elemental analysis techniques. As a heterogeneous catalyst, Ru-SO3-SBA-15 exhibited comparable activity and selectivity to the parent homogeneous catalyst [(RuCl4)-Cl-III(L)(2)]PF6 in transfer hydrogenation of ketones. However, as a result of the limited durability of Ru-SO3-SBA-15 in strongly alkaline environments at high temperature, the activity of Ru-SO3-SBA-15 could not be maintained during subsequent recycled uses.