Abstract Vanadium oxyphosphate (VPO) with a high surface area was synthesized in a mixed solvent of ionic liquid [Bmim]Br and water, using phosphorous acid to reduce V 5+ to V 4+ and as a partial phosphorus source, and V 2 O 5 as the vanadium source. The effects of ionic liquids on the synthesis process were investigated in detail. Using pure water as the solvent, the product was a vanadium phosphate compound with large flakes. With the increase in the amount of ionic liquid, the size of the large flakes of vanadium phosphate gradually decreased, and the morphology was changed to spherical particles. When the proportion of ionic liquid was 80% or the ionic liquid was solely used as the solvent, the VPO showed completely spherical particle morphology, and the specific surface area was the highest. X-ray diffraction analysis showed that the crystal phase of VPO changed from vanadium (IV) hydrogenphosphate hemihydrate (VOHPO 4 ·0.5H 2 O) to an amorphous state with an increase in ionic liquid ratio. All of the above results show that ionic liquids play an important role in the synthesis of VPO materials. After being calcined in an n-butane/air atmosphere, the precursors were transformed into the vanadium pyrophosphate phase. The active VPO catalysts were used in the selective oxidation of cyclohexanol, and the yield of cyclohexanone was 57.98% for the VPO-80 catalyst synthesized using the ionothermal method but only 21.41% for the VPO-W catalyst synthesized using a traditional hydrothermal method, which shows the advantage of ionic liquid synthesis for VPO catalysts. Graphic Abstract Vanadium oxyphosphate material with high surface area was synthesized in the mixed solvent of ionic liquid [Bmim]Br and water. Ionic liquid plays an important role in the morphology and properties of synthesized VPO materials. The active VPO catalysts were used in the selective oxidation of cyclohexanol, and the yield of cyclohexanone was 57.98% for VPO-80 catalyst synthesized by ionothermal method, but only 21.41% for VPO-W catalyst synthesized by traditional hydrothermal method, which exhibited the advantages of ionic liquid synthesis for VPO catalysts.

中文翻译：

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用于选择性氧化反应的亚磷酸离子液体辅助合成磷酸钒催化剂

摘要 在离子液体[Bmim]Br和水的混合溶剂中，以亚磷酸将V 5+ 还原为V 4+ 并作为部分磷源，V 2 O 合成了高表面积氧磷酸钒（VPO）。 5 作为钒源。详细研究了离子液体对合成过程的影响。以纯水为溶剂，产物为大片状磷酸钒化合物。随着离子液体用量的增加，磷酸钒大片的尺寸逐渐减小，形态变为球形颗粒。当离子液体的比例为80%或单独使用离子液体作为溶剂时，VPO呈完全球形的颗粒形态，比表面积最高。X射线衍射分析表明，随着离子液体比例的增加，VPO的晶相由半水合磷酸氢钒(VOHPO 4 ·0.5H 2 O)转变为非晶态。以上结果表明，离子液体在VPO材料的合成中发挥着重要作用。在正丁烷/空气气氛中煅烧后，前体转化为焦磷酸钒相。活性VPO催化剂用于环己醇的选择性氧化，离子热法合成的VPO-80催化剂环己酮的产率为57.98%，而传统水热法合成的VPO-W催化剂的环己酮收率仅为21.41%。显示了离子液体合成用于 VPO 催化剂的优势。图形摘要 在离子液体[Bmim]Br和水的混合溶剂中合成了高表面积氧磷酸钒材料。离子液体在合成 VPO 材料的形态和性能中起着重要作用。将活性VPO催化剂用于环己醇的选择性氧化，离子热法合成的VPO-80催化剂环己酮的收率为57.98%，而传统水热法合成的VPO-W催化剂的环己酮收率仅为21.41%，体现了优势用于 VPO 催化剂的离子液体合成。