Influence of Phosphine Concentration on Propylene Hydroformylation over the PPh3-Rh/SiO2 Catalyst

The effect of triphenyl phosphine concentration in the novel PPh 3 -Rh/SiO 2 catalyst for propylene hydroformylation was studied and found an optimum P/Rh ratio of 15, a butyraldehyde n / i ratio of 14, a butyraldehyde TOF of 241 h −1 , and high catalytic stability for PPh 3 -Rh/SiO 2 . Solid-state 31 P NMR shows that in an atmosphere of syngas the physically adsorbed PPh 3 migrates onto the surface of Rh/SiO 2 where it chemically adsorbs and then promotes the in situ formation of carbonyl phosphine complexes. ：研究了 P/Rh 比对 PPh 3 -Rh/SiO 2 催化剂上丙烯氢甲酰化反应性能的影响. 结果表明, 当 P/Rh 比为 15 时, 丙烯氢甲酰化反应性能最好, 丙烯转化率为 25.9%, 产物丁醛正异比为 14, 转换频率为 241 h −1 . PPh 3 -Rh/SiO 2 催化剂的固体 31 P 核磁共振结果表明, 在合成气气氛下, 物理吸附的 PPh 3 能够溢流到 Rh/SiO 2 表面形成化学吸附的 PPh 3 , 从而促进了具有氢甲酰化活性的铑膦络合物的形成. Wilkinson 催化平衡理论也很好地解释了本实验结果. In a syngas atmosphere, the physically adsorbed PPh3 in PPh3-Rh/SiO2 catalysts migrate onto the surface of Rh/SiO2 and are chemically adsorbed before promoting the in situ formation of carbonyl phosphine complexes.