| Ruthenium nanoparticles( I ) and (II) stabilized by PEG-4000 was prepared by reduction of PETPP/Ru3(CO)12 complex and Ru3(CO)12 TEM analysis of these two Ru° nanoparticles shows that the nanoparticle size is about 3-4nm. These two Ru0 nanoparticles have been used in the thermoregulated PEG biphasic hydrogenation of olefins, meanwhile the seperation and recycling efficiency of the catalyst has been investigated.The Ru0 nanoparticles( I ) was used in the PEG biphasic hydrogenation of styrene, the effects of pressure of H2, reaction time, and the ratio of S/Ru on the reaction were tested and discussed in detail. The preferable reaction conditions are as follows: S/Ru=1000, 90℃, 1MPaH2, t=30min. Under the above refined reaction conditions, the yield of ethylbenzene is 100%, TOF=2000h-1. After 8 times of the catalyst recyling, the yield of ethylbenzene is still above 98%. After 8 times recyling, the Ru° nanoparticles was characterized by TEM. The size of nanoparticle is still 3-4nm.The Ru0 nanoparticles( II) was used in the PEG biphasic hydrogenation of styrene and 1-octene. Under the reaction conditions of S/Ru=4000, 90℃, 1MPa(H2), t=1h, the yield of products is 99%, TOF=3960 h-1. After 10 times of the catalyst recyling, the yield of products is still above 99%. After recycling, TEM analysis shows that the size of nanoparticle is still 3-4nm.The Ru0 nanoparticles( II) was used in the PEG biphasic hydrogenation of cyclohexene, under the reaction conditions of S/Ru=4000, 90℃, 1.5MPa(H2), t=1h, the yield of cyclohexane is 99%, TOF=3960 h-1. After 10 times of the catalyst recyling, the yield of cyclohexane is still above 99%.Moreover the Ru° nanoparticle stabilized by PETPP has been synthesized by thermal decomposition of PETPP/Ru3(CO)12 complex. The size of the Ru° nanoparticle is 1.0-1.5nm. The Ru° nanoparticle was used in the hydrogenation of olefins. This catalyst exhibits good catalytic activity and recycling efficiency.
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