磺化Salen金属配合物插层水滑石选择性催化氧化甘油制备二羟基丙酮的研究

制备了一系列含不同金属离子的磺化Salen金属配合物插层水滑石催化剂用于甘油催化氧化制备二羟基丙酮(DHA)。利用X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)及电感耦合等离子发射光谱(ICP)分析手段对催化剂进行了表征。结果表明,磺化Salen配体插入镁铝水滑石(LDH)层板间,金属离子与磺化Salen配体配合,制备出磺化Salen金属配合物插层的水滑石非均相催化剂。反应结果表明,含Cr³⁺及含Cu²⁺催化剂有利于H₂O₂活化,催化活性较高,含Cu²⁺催化剂利于甘油脱氢,DHA选择性较高。含Cu²⁺催化剂用于甘油催化氧化反应时,在pH值为7、60 ℃条件下反应4 h,甘油转化率为40.3%,DHA选择性达到52.9%。

Selective oxidation of glycerol to dihydroxyacetone over layer double hydroxide intercalated with sulfonato-salen metal complexes

A series of sulfonato-salen metal complexes were intercalated into Mg-Al layer double hydroxide (LDH) and used for selective oxidation of glycerol to dihydroxyacetone (DHA). The X-ray diffraction, Fourier transform infrared spectroscopy and elemental analysis results of the as-prepared catalysts demonstrated that the metal ions were combined with sulfonato-salen ligands to form metal complexes that intercalated in the LDH. The Cr(III) and Cu(II) sulfonato-salen complex-intercalated LDH catalysts were favorable for activation of H₂O₂, promoting the oxidation of glycerol to DHA. It was found that the Cu(II) sulfonato-salen-intercalated LDH catalyst was also beneficial for the dehydrogenation of glycerol, resulting in a high selectivity to DHA. The glycerol conversion and DHA selectivity obtained over the Cu(II) sulfonato-salen-intercalated LDH catalyst reached 40.3% and 52.9% respectively under the optimum reaction conditions of 60 ℃, 4 h and pH value 7.