γ-Al2O3/MoO3固体酸催化剂合成过氧乙酸OA

As H2SO4 have disadvantages in the acetic acid oxidation method for preparing peracetic acid(PAA),such as difficulty in separation,poor recoverability and challenging post-treatment.A series of γ-Al2O3 supported MoO3 composites(γ-Al2O3/MoO3)were prepared by the impregnation-calcination method using γ-Al2O3 and ammonium molybdate tetrahydrate as raw materials,in which γ-Al2O3/MoO3 was used as a solid acid catalyst instead of H2SO4 for synthesizing PAA.NH3-TPD results show that γ-Al2O3/MoO3-65 possesses weak acid sites,medium acid sites and strong acid sites.Moreover,the strength of the weak acid sites or medium acid sites is significantly greater than MoO3.γ-Al2O3 has a strong Lewis acid property in the composite material,so Lewis acid strength of Al/Mo-65 is higher.With the temperature rises,the strength of Br􀱽nsted acid and Lewis acid of Al/Mo-65 decreases in pyridine-infrared spectrum.γ-Al2O3/MoO3 can be used to prepare PAA under mild conditions.Among them,the mass of Al/Mo-65 is 0.6 g,the concentration of PAA reaches 6.76%at 30℃for 24 h when the mass ratio of CH3COOH to H2O2 is 1∶1(60 g in total).The catalyst is recycled 5 times,and the concentration of PAA is 3.65%.Comparison of XRD before and after Al/Mo-65 usage,the composition of the catalyst remains unchanged.But the characteristic diffraction peak intensity of MoO3 in the used Al/Mo-65 is weakened.The active component of the Al/Mo-65 is lost.Self-made PAA has good antibacterial effect against Escherichia coli and Staphylococcus aureus.