金属掺杂纳米固体超强酸SO2-4/ZrO2的IR考察

首先采用sol-gel法制备出ZrO(OH)2，再分别用Ni^2 ，Al^3 ，Sn^4 ，Ag^ ，Sn^2 金属盐溶液和H2SO4稀溶液浸渍ZrO(OH)2的方法合成了一系列金属离子掺杂的SO4^2-／ZrO2纳米固体超强酸。并用XRD，TEM和IR技术考察了各样品的性能。结果发现，经不同金属掺杂的SO4^2-／ZrO2颗粒具有固体超强酸的IR谱特征。经NiH，Sn^4 掺杂的样品中Zr-O和S-O键振动吸收峰明显蓝移，Zr-O的vZr-O由SO4^2-／ZrO2的485cm^-1增大到Ni^2 ，Sn^4 掺杂样品的500cm^-1，s=0的vas由1390cm^-1增大到1405和1400cm^-1，而Sn^2 掺杂的样品变化不大。说明Ni^2 ，Sn^4 金属离子的掺杂增强了样品的超强酸性。同时还发现，随着样品焙烧温度的提高，经Ni^2 和Al^3 掺杂的SO4^2-／ZrO2纳米颗粒，Zr-O和S=O键振动吸收峰明显蓝移，而Ag^ 掺杂的样品在焙烧温度达到1073K时IR谱只是吸收强度减弱，振动频率不变。

Observation of IR Spectra from Doped SO2-4/ZrO2 Nanosolid Superacid

In this paper, ZrO(OH)2 was prepared with sol-gel method, then a series of metal-ions-doped SO(2)4- /ZrO2 nanosolid superacids were prepared by impregnated ZrO(OH)2 using diluted H2SO4 and Ni2+ , Al3+, Sn4+, Ag+ , Sn2+ etc. salt solutions. The samples were characterized by IR, XRD, TEM and chemical analysis method. The result shows that the IR spectra of samples are the characteristic spectra of the solid superacids. The stretching frequencies of Zr--O and S==O in Ni2+ and Sn4+ doped samples are obviously increased, the v(Zr-o) values of Zr--O increase from 485 cm(-1) for SO(2)4- /ZrO2 to 500 cm(-1) for both Ni2+ and Sn4+ doped samples, the v(as) values of S==O increase from 1 390 cm(-1) for So(2)4- /ZrO2 to 1405 and 1400 cm(-1) for Ni2+ and Sn4+ doped samples respectively, but that in Sn2+ doped sample increases a little. It is indicated that the samples doped by Ni2+ and Sn4+ show higher super acidity than SO(2)4- /ZrO2 . The IR spectra of samples were determined at different calcination temperatures. It was found that the stretching frequencies of Zr--O and S==O in Ni2+ and Al3+ doped samples are obviously increased with the increase in calcination temperature, but that in Ag+ doped sample is not.