Hydroformylation Of Styrene And P-Isobutyl Styrene Catalyzed By Thermoregulated Phase-Separable Rhodium Nanoparticles

Rh nanoparticles stabilized by ionic liquids (IL)([(CH3OCH2CH2OCH2CH2)(n-C8H17O CH2CH2OCH2CH2) N+(CH3)2CH3SO-3]) were prepared by hydrogen reduction of RhCl3·3H2O TEM image showed that the average size of Rh nanoparticles was1.6nm with standard deviation of0.2nm.The thermoregulated phase-separable Rh nanoparticle catalyst was applied for the hydro formylation of styrene. The Rh nanoparticle catalyst exhibited highly catalytic activity and good recyclability. Under the optimized reaction conditions, styrene/Rh=5000:1(molar ratio), syngas pressure P=6MPa (CO:H2=1:1),t=3h, T=120℃, the conversion of styrene was more than99%, and the yield of aldehydes was97%. The catalyst can be reused20times without evident loss in activity.The value of TON was97000, ICP-AES detect the average leaching of rhodium in organic phase was2.6wt%. With the aid of IR and Mercury poison experiments, we further explore the reaction of mechanism.The thermoregulated phase-separable Rh nanoparticle catalyst was also employed for the hydro formylation of p-isobutyl styrene (IBS). The effects of reaction temperature, reaction time, syngas pressure, the molar ratio of IBS/Rh and solvent the amount of on the reaction were investigated in detail. Under the optimized reaction conditions, T=120℃, P=6MPa (CO:H2=1:1), t=3h, S/C=5000:1(molar ratio), IL/Rh=400:1(molar ratio). The catalyst can be reused8times without evident loss of activity.The value of TON was38400, and the average leaching of rhodium in organic phase was0.62wt%.