摘要
通过超声辅助的工艺,利用氧化还原法制备出多价态纳米MnO_x。通过调节超声时间、KMnO_4浓度、烘干温度、反应溶液pH,探索MnO_x的最佳合成条件。结果表明:超声时间20 min,高锰酸钾浓度0.5 mol/L,烘干温度80℃,反应溶液pH=7的条件下,合成的样品MnO_x表现出最佳的催化性能,对100%的NO去除率可持续15 h。采用X射线衍射分析(XRD)、N_2-吸脱附测试、扫描电镜(SEM)、透射电镜(TEM)等技术考察最优催化剂MnO_x的结构和形貌,借助X射线光电子能谱(XPS)和傅里叶红外分析(FT-IR)研究最优催化剂MnO_x对NO去除的催化氧化机理以及催化剂的失活机制。结果表明,三维贯穿的多级孔结构,花瓣状的形貌和弱晶化的晶体结构有利于气体吸附和传输。多价态Mn和氧空位的存在促进了NO和O_2的吸附和激活,因此最优样品MnO_x表现出优异的NO的常温催化氧化。
The varied-valence nanocatalyst MnOx was prepared using the oxidation-reduction method under ultrasonic.The optimal synthetic conditions of MnOx were explored by adjusting the ultrasonic time,concentration of reaction precursor,drying temperature,and pH of reaction solution.The results indicated that the optimal sample MnOx was synthesized under the condition of ultrasonic time of 20 min,0.5 mol/L KMnO4,drying temperature of 80℃and pH=7,which showed the super catalytic performance and the time of 100%NO removal rate was as high as 15 h at room temperature.The structure and morphology of the optimal catalyst MnOx were investigated by XRD,N2-adsorption-desorption analysis,SEM and TEM.Besides,XPS and FT-IR were also applied to explore the catalytic oxidation process of NO removal and the deactivation mechanism of the optimal sample MnOx.It is believed that the interpenetrating and hierarchal pore,the petaloid morphology and weak crystallization structure contribute to the gas adsorption and transmission.The presence of varied-valence Mn and oxygen vacancy can improve the adsorption and activation of NO and O2,thus,enhancing the NO catalytic removal on the optimal catalyst MnOx at room temperature.
作者
龚云
刘艳
顾萍
朱钰方
周晓霞
GONG Yun;LIU Yan;GU Ping;ZHU Yu-Fang;ZHOU Xiao-Xia(Department of Printing and Packing,Shanghai Publishing and Printing College,Shanghai 200093,China;School of Material Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第2期186-192,共7页
Journal of Inorganic Materials
基金
柔版印刷绿色制版与标准化实验室开放课题基金(2BKT201803)~~
关键词
MNOX
低浓度NO
超声
纳米材料
氧化
MnOx
low concentration NO
ultrasonic
nano materials
oxidation
