新型功能材料:磁性固体超强酸SO_4^(2-)/ZrO_2-MgO-Fe_3O_4的合成及表征

Novel functional material: synthesis and characterization of magnetic solid superacid SO_4^(2-)/ZrO_2-MgO-Fe_3O_4

利用化学共沉淀法将磁性基质与固体酸组装制备磁性纳米固体超强酸,借助XRD、TEM、HR-TEM、TG-DSC、VSM等手段对样品进行表征。结果表明:MgO的掺杂及磁性基质的引入延缓了ZrO2由T-ZrO2向M-ZrO2转化的趋势;样品粒径分布均匀,平均为30nm;HRTEM显示T-ZrO2晶体生长取向于[101]方向,晶面间距d(101)=0.29nm;磁性基质的引入赋予了固体超强酸以超顺磁性;Hammett指示剂法测得经800℃焙烧后产物的酸强度Ho<-13.8,酸性大于浓硫酸(Ho=-11.93)。

Magnetic solid superacids SO4^2-/ZrO2-MgO-Fe3O4 were prepared by the chemical co-precipitation approach. The obtained materials were characterized by XRD, TEM, HRTEM,TG-DSC, VSM. The results indicated that The introduction of MgO and Fe3O4 delays the transition from T-ZrO2 to M-ZrO2 ; the magnetic solid superacid catalysts have superparamagnetism because of the existence of Fe3O4 particles; The samples show well-defined crystallographic faces and the average size in diameter is 30nm; The HRTEM shows that the interplanar spacing is d（101） =0.29nm, the sample after calcination at 600℃ was estimated to have Ho〈-13.8. The superacid that is stronger than Ho=- 11. 93, which corresponds to the acid strength of 100% H2SO4, is known as a acid.