The SO42-/WO3-TiO2 solid superacid samples have been prepared by ageing at low temperature. The acidity of samples were determined with flowing indicator method, and the characterization of the samples were performed ...The SO42-/WO3-TiO2 solid superacid samples have been prepared by ageing at low temperature. The acidity of samples were determined with flowing indicator method, and the characterization of the samples were performed by IR, XPS and XRD. The samples were used in the esterification of acetic acid and glycerol. The results show that the sample aged at low temperature have better performance comparing with other samples aged at normal temperature, the flexible vibration peak of S=O bond has been strengthened remarkably in IR spectra. The peak position of W4f have a higher chemical shift in XPS patterns. The diffraction peaks of tetragonal and orthographic phase of WO3 are stronger in XRD patterns. The process of ageing at low temperature is responsible for the stronger acidity and higher activity of SWT samples.展开更多
文摘The SO42-/WO3-TiO2 solid superacid samples have been prepared by ageing at low temperature. The acidity of samples were determined with flowing indicator method, and the characterization of the samples were performed by IR, XPS and XRD. The samples were used in the esterification of acetic acid and glycerol. The results show that the sample aged at low temperature have better performance comparing with other samples aged at normal temperature, the flexible vibration peak of S=O bond has been strengthened remarkably in IR spectra. The peak position of W4f have a higher chemical shift in XPS patterns. The diffraction peaks of tetragonal and orthographic phase of WO3 are stronger in XRD patterns. The process of ageing at low temperature is responsible for the stronger acidity and higher activity of SWT samples.
