臭氧在SnO2表面吸附的红外光谱研究

以SnO2催化臭氧化降解高浓度糖蜜酒精废水为探针反应,研究SnO2催化臭氧化降解糖蜜酒精废水的活性,并采用红外光谱研究臭氧在SnO2及金属氧化物改性的SnO2催化剂表面的吸附行为。结果表明:由纯氧源制得的O3在SnO2表面吸附的红外光谱上的1 027和1 055 cm-1及2 099和2 122 cm-1处存在两处明显的吸收双峰,而空气制备的O3在SnO2表面与CO及CO2等存在竞争吸附,使得O3的吸附减少,催化臭氧化降解糖蜜废水的降解率下降。催化剂助剂对SnO2催化臭氧化降解糖蜜酒精废水有较大的影响。采用Fe2O3,NiO,CuO,ZnO,MgO,SrO及BaO等金属氧化物为助剂改性的SnO2在2 236和2 213 cm-1,1628和1 599 cm-1出现强度相似的吸收峰,但是几种催化剂对CO2和CO的吸附差别较大,过渡金属改性的SnO2在1 580~1 070 cm-1处出现较宽的吸收峰,碱土金属氧化物改性的SnO2催化剂在1 580~1 070 cm-1之间,出现了1 298和1 274 cm-1两个新的峰,从而引起了不同助剂催化臭氧化的活性差别,碱土金属改性的SnO2对糖蜜酒精废水的催化臭氧化脱色效果明显优于过渡金属改性的SnO2,其中BaO改性的SnO2催化剂的活性最好。

Infrared Study on Adsorption of O3 at SnO2 Surface

SnO2 was prepared by precipitation method and mental oxides modified SnO2 catalysts were prepared by coprecipitation method.High concentration molasses fermentation wastewater degradation by SnO2 catalyzed ozonation was used as a probe reaction and IR spectra were used to study the adsorption of O3 at SnO2 and different metal oxides modification SnO2 surface.The results showed,that in the infrared absorption spectra of adsorption of O3 prepared by pure O2 at SnO2 catalyst surface,two obvious bidentate absorption double peaks were found at 1 027 and 1 055 cm-1,and 2 099 and 2 122 cm-1,respectively.However,there was competitive adsorption between O3 prepared by air,and CO and CO2.Then the O3 adsorption decreased,leading to the decrease in the degradation of molasses fermentation wastewater by SnO2 catalytic ozonation,and after 60 min reaction,the degradation rate by pure oxygen as oxygen source was 79.2%.It was 33.1% more by air as oxygen source.Similar strength adsorption peaks in the infrared spectra were found at 2 236,2213 cm-1 and 1 628,1 599 cm-1 with Fe2O3,NiO, CuO,ZnO,MgO,SrO and BaO modified SnO2.But the adsorption of CO2 and CO was different on modifier-SnO2,There was a wide absorption peak at 1 580-1 070 cm-1 in the infrared spectra of transition metal modified SnO2,and two new peaks at 1 298 and 1 274 cm-1 were found between 1 580 and 1 070 cm-1 in the infrared spectra of alkaline-earth metals modified SnO2 catalysts.These changes leaded to a different catalytic ozonation activity of modifier-SnO2,the results of molasses fermentation wastewater degradation by ozone combined with alkaline-earth metal modified SnO2 was obviously better than ozone combined with transition metal modified SnO2.And among them,the ozonation catalytic activity of BaO-SnO2 was the best.