Adsorption and Reactions of Dimethylsulfoxide on Powdered TiO2

• Main Authors: Sin-JhangHuang, 黃信彰
• Other Authors: Jong-Liang Lin
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/82100268607213316951

碩士 === 國立成功大學 === 化學系碩博士班 === 100 === Fourier-transform infrared spectroscopy has been employed to investigate the adsorption and reactions of dimethylsulfoxide (DMSO) on powdered TiO2. DMSO is adsorbed molecularly on TiO2 surface at 35 oC. DMSO on TiO2 is subjected to thermal decomposition, producing the surface species of CH3O, HCOO and S under vacuum. The formation of CH3O and HCOO is likely originated from the transient reaction intermediate of -OCH2O-, which is formed by dissociating both the C-S and C-H bonds of DMSO. In the presence of O2, the thermal reaction products and rate are similar to those under vacuum, generating CH3O and HCOO. This indicates that O2 has negligible effect on the thermal decomposition pathway and kinetics of DMSO, but oxidizes the reaction product of S(a) to SO4(a). Photodegradation of DMSO on TiO2 generates CH3O(a), HCOO(a), H2O(a) and CH3S(a) in the absence of O2. In the case of DMSO photoreaction in the presence of O2, CH3O(a), HCOO(a), H2O(a), CO2(g) and CH3SO3(a) are formed. O2 can enhance the photodegradation of DMSO. The photochemistry is proposed to proceed primarily by H abstraction from DMSO, followed by decomposition of the CH3S(O)CH2∙ species.