摘要
目的:通过制备四种不同晶型的二氧化锰,对其结构进行了详尽表征,并对其低浓度甲醛降解性能进行探索。方法:采用KMnO_(4)、NH_(4)Cl、MnSO_(4)·H_(2)O、(NH_(4))_(2)S_(2)O_(8)为原料合成了四种不同晶型的二氧化锰,通过X射线衍射(XRD)、红外光谱、氮气吸脱附、X射线光电子能谱(XPS)、透射电子显微镜(TEM)等对材料进行表征。将四种催化剂应用于低浓度甲醛降解测试。结果:制备得四种晶型的二氧化锰,XRD结果表明分别为α-MnO_(2)、β-MnO_(2)、γ-MnO_(2)和δ-MnO_(2);氮气吸脱附结果表明δ-MnO_(2)的比表面积最大,β-MnO_(2)的比表面积最小;XPS结果δ-MnO_(2)的表面氧与氧缺陷占比最高、Mn的平均价态最高;TEM结果表明α-、δ-MnO_(2)具有明显的层状结构,其余晶型为棒状。结论:制备得四种晶型的二氧化锰,对甲醛降解最高的是δ-MnO_(2),6 h后可达80%,说明δ-MnO_(2)具有较好的催化降解效果。
Aims:Four different crystal forms of manganese dioxide were prepared and characterized to explore the catalytic degradation performance of low-concentration formaldehyde.Methods:KMnO_(4),NH_(4)Cl,MnSO_(4)·H_(2)O and(NH_(4))_(2)S_(2)O_(8) were used to synthesize four different crystal forms of manganese dioxide.The structures of the catalysts were characterized by XRD,infrared spectroscopy,nitrogen adsorption and desorption,XPS,TEM,etc.The degradation performance of low-concentration formaldehyde was tested.Results:XRD results showed that four crystal forms of manganese dioxide wereα-MnO_(2),β-MnO_(2),γ-MnO_(2),δ-MnO_(2).Nitrogen adsorption and desorption results showed that the specific surface area ofδ-MnO_(2) was the largest;and the smallest one wasβ-MnO_(2).XPS results showed thatδ-MnO_(2) had the highest surface oxygen and oxygen defect ratio;and the average valence of Mn was the highest.TEM results showed thatα-andδ-MnO_(2) had an obvious layered structure,and that other materials were rod-like structures.Conclusions:δ-MnO_(2) showed the highest degradation of formaldehyde among the four crystalline MnO_(2)(α-MnO_(2),β-MnO_(2),γ-MnO_(2),δ-MnO_(2)),which reached 80%after 6 hours,which indicates thatδ-MnO_(2) has excellent catalytic degradation effect.
作者
韩哲
俞天寿
柳宛彤
张明
金红晓
葛洪良
王新庆
金顶峰
HAN Zhe;YU Tianshou;LIU Wantong;ZHANG Ming;JIN Hongxiao;GE Hongliang;WANG Xinqing;JIN Dingfeng(College of Materials and Chemistry,China Jiliang University,Hangzhou 310018,China;Department of Environmental Engineering,China Jiliang University,Hangzhou 310018,China)
出处
《中国计量大学学报》
2021年第1期124-131,共8页
Journal of China University of Metrology
基金
浙江省自然科学基金项目(No.LY16B030006)。
关键词
甲醛
催化氧化
二氧化锰
降解
formaldehyde
catalyst oxidation
manganese dioxide
degradation
