[Observation of IR spectra from doped SO(2)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/ZrO_2 nanosolid superacids were prepared by impregnated ZrO(OH)_2 using diluted H_2SO_4 and Ni 2+, Al 3+, Sn 4+, Ag+, Sn 2+ 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 SO in Ni 2+ and Sn 4+ doped samples are obviously increased, the ν_ Zr—O values of Zr—O increase from 485 cm -1 for SO 2-_4/ZrO_2 to 500 cm -1 for both Ni 2+ and Sn 4+ doped samples, the ν_ as values of SO increase from 1 390 cm -1 for SO 2-_4/ZrO_2 to 1 405 and 1 400 cm -1 for Ni 2+ and Sn 4+ doped samples respectively, but that in Sn 2+ doped sample increases a little. It is indicated that the samples doped by Ni 2+ and Sn 4+ show higher super acidity than SO 2-_4/ZrO_2. The IR spectra of samples were determined at different calcination temperatures. It was found that the stretching frequencies of Zr—O and SO in Ni 2+ and Al 3+ doped samples are obviously increased with the increase in calcination temperature, but that in Ag+ doped sample is not.