Synthesis of novel nanotubular mesoporous nickel phosphates with high performance in epoxidation

Abstract

Two novel mesoporous nickel phosphates (NiPO-1 and NiPO-2) with nanotubular structures were developed in the presence of cationic surfactant and different bases by a sol–gel method. The mesostructures of NiPO-1 and NiPO-2 are composed of nanotubes of different lengths, which are arranged by a less-ordered lamellar symmetry as synthesized. ICP elemental analysis revealed that they are different compounds. The Ni/P molar ratios of NiPO-1 and NiPO-2 are 1.57 and 1.20, respectively. Both materials possess a relatively high BET surface area (205–292 m² g⁻¹) and good thermal stability up to 673 K. It is found that these novel materials exhibited high activity (>50%) and high selectivity to epoxide (95.6% and 99.0%) in the epoxidation of cyclododecene with H₂O₂ as oxidant.