Synthesis And Catalytic Properties Of Mesoporous Phosphates And Multi-metal Phosphates

Catalytic performance of mesoporous NiPOs on the electro-oxidation of methanol was studied in alkaline medium in comparison with VSB-5,NiO and Ni(OH)2. It was found that mesoporous NiPO-2showed relatively high activity and stability because of shorter pore canal and higher nickel content. Higher methanol concentration and scan rates could improve the catalytic activity of NiPO-2on the electro-oxidation of methanol. NiPO-2showed good stability as its anodic current density remains64%of its highestl value after1000cycles.Li-NiPO-2、Zn-NiPO-2、Fe-NiPO-2and La-NiPO-2were developed in the presence of cationic surfactant by a sol-gel method. We evaluated the catalytic performance of M-NiPO-2in epoxidation of cyclohexene. It was found that La-NiPO-2and Zn-NiPO-2could improve selectivity of epoxy compound, while Fe-NiPO-2could improve the conversion of cycloalkenes.Si-NiPOs were successfully synthesized by sol-gel method. The catalytic performance of Si-NiPOs in epoxidation of cyclohexene was studied. Si-NiPO-2could improve the selectivity of epoxy compound. When n(Si)/n(P) is0.3, selectivity to epoxy compound was95.69%. Besides, catalytic performance of Si-NiPOs on the electro-oxidation of methanol was evaluated. Eleco-catalytic reaction results showed that Si-NiPO-2exhibited relatively high activity and stability. When n(Si)/n(P) is0.3, the electro-oxidation of methanol was the best and the strength of the oxidation current is about four times than that of NiPO-2.Mesoporous FePO and MgPO were developed in the presence of cationic surfactant by hydrothermal method and sol-gel method. It is found that FePO and MgPO showed relatively high convertion and selectivity to epoxide in epoxidation of cyclohexene and cyclododecene. Mesoporous FePO and MgPO showed good stability as its catalytic activity remains the same as the fresh sample after3cycles.