| Mesostructured nickel phosphates (MW-NiPO-1 and MW-NiPO-2) were rapidly synthesized via a microwave assisted hydrothermal process. The synthesis parameters of MW-NiPO-2 were systematically investigated and optimized. The results show that ordered MW-NiPO-2 can be obtained under microwave irradiation for 1 h at 100℃, when the OH-/P and the Ni/P molar ratios of the precursor are 2.0 and 0.7, respectively. The framework, BET surface area and pore structure of MW-NiPO-2 were characterized by ICP, FT-IR, TEM, and N2 physisorption. In contrast to the sample synthesized via a sol-gel method, this material possesses a relatively high BET surface area (334.4 m2/g) and pore volume (0.318 cm3/g). MW-NiPO-2 was used as the catalyst of the epoxidation of cyclohexene using hydrogen peroxide as the oxidant. The reaction conversion and the selectivity of epoxycyclohexane over MW-NiPO-2 were higher than those over NiPO-2, and less hexadienol was produced.Mesoporous nickel phosphate (NiPO-3) was synthesized with urea as alkali by sol-gel method. In contrast to NiPO-1 and NiPO-2, NiPO-3 possesses relatively longer nanotubes which reach up to 400～600 nm. N2 physisorption shows that NiPO-3 possesses higher BET surface area (345.8m2g-1), bigger pore volume (0.46 cm3g-1) and larger pore size (5.3 nm). Moreover, the catalytic performance of NiPO-3 shows that the total selectivity of epoxycyclohexane and hexadienol is as high as 83.38%.Silicon-nickel phosphates (Si-NiPO-1 and Si-NiPO-2) were successfully synthesized with tetraethylorthosilicate as silicon resource by sol-gel method. We found that silicon-nickel phosphates have similar structure with NiPO-1 and NiPO-2, but different surface quality and pore characteristics. The result shows that the addition of small amount of silicon can increase the BET surface area and pore volume, and enlarge the pore size. Therefore, Si-NiPO-1 and Si-NiPO-2 have different catalytic performance on the epoxidation of cyclohexene.
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