Catalytic Property And Chemical Modification Of Mesoporous NiPOs

We evaluated the catalytic performance and structural stability of NiPOs in epoxidation of cyclohexene and cyclododecene under mild conditions. The reaction results showed that the appropriate oxidant and solvent were respectively hydrogen peroxide and acetonitrile, and the appropriate treated temperature of catalyst was360℃, when added Free radical polymerization inhibitor into the reaction, we found that allylic oxidizing reaction followed the free radical reaction mechanism。When increase the hydrogen peroxide or the reaction time, the conversion of cyclohexene and selectivity of cyclohexane all showed ascendant trend, but with the increase of acetonitrile or catalyst, the conversion of cyclohexene and selectivity of epoxy cyclohexane all showed descend trend. Comparised with other porous materials’catalysis property, we found that mesoporous phosphate nickel had better catalytic property, and when recycle used for the third time, it still had very high catalytic activity. In addition, mesoporous phosphate nickel also showed very good catalytic performance in the epoxidation of cyclododecene, the cyclododecene conversion can reached21.1%, and the selectivity of epoxide was78.1%After silanized by hexamethyldisilazane (HMDS), NiPO-3showed higher activity and selectivity to epoxide in the epoxidation of cycloalkenes with H2O2as oxidant. The convertion of cyclohexene is42.5%, the epoxide selectivity is88.5%, and the convertion of cyclodecene is24.4%, the epoxide selectivity is97.7%. We also found that, the template of As-NiPO-3was partly removed in the processe of silanization.We introduced transition metal (Co,Cu) and alkaline metal (Mg) into the synthesized process of NiPO-3. XRD, FT-IR and Uv-vis showed that Co, Cu and Mg were successfully introduced into the skeleton of NiPO-3. Catalytic reaction results showed that, after introduced Co, Cu into NiPO-3, the convertion of cycloalkenes improved, but the selectivity of epoxide decreased; and the introduce of Mg into NiPO-3can improve selectivity of epoxide.