摘要
以高锰酸钾和(或)硫酸锰为锰源,分别采用水热法和PVA保护的硼氢化钠还原法,制备了一维纳米棒状、线状和管状x Au/MnO_2(x为2%、4%、8%和10%)催化剂。一维棒状、线状和管状x Au/MnO_2中的MnO_2均为四方晶相α-MnO_2,其α-MnO_2样品的比表面积为48.4~114.0 m2/g。棒状4%Au/α-MnO_2的催化活性最好:在空速为20 000 m L/(g·h)的条件下,CO转化率达到50%和90%时的反应温度(T50%和T90%)分别为11.4和16.3℃;氧化甲苯的T50%和T90%分别为210和225℃。基于大量的表征结果和多组催化活性数据分析发现,棒状4%Au/α-MnO_2催化剂催化活性最好的主要原因是其低温还原性能最好、吸附氧物种浓度较高、催化剂上的Au纳米粒子高度分散、Au纳米粒子与α-MnO_2纳米棒之间有较强相互作用。
1-D nanosized rod-like,wire-like,and tubularα-MnO2(x Auα-MnO2,x=2%,4%,8%,10%)were prepared using the hydrothermal and PVA-protected NaBH 4 reduction methods at different temperatures with KMnO4 and or MnSO 4 as Mn source,respectively.It is shown that theα-MnO2 in x Auα-MnO2 was tetragonal in crystal structure,surface area ofα-MnO2 nanorods,nanowires,and nanotubes was in the range of 48.4-114.0 m 2 g.The 4%Auα-MnO2 sample possessed the highest adsorbed oxygen species concentration and the best low-temperature reducibility,thus showing the highest catalytic activity:the T 50%and T 90%(temperatures required for achieving reactant conversions of 50%and 90%)were 11.4 and 16.3℃for CO oxidation,and 210 and 225℃for toluene oxidation at a space velocity of 20000 mL(g·h),respectively.Based on the characterization results and activity data,it is concluded that the better low-temperature reducibility,higher oxygen adspecies concentration,highly dispersed Au NPs,and stronger interaction between Au NPs and MnO2 nanorods were the main factors influencing the catalytic performance of 4%Auα-MnO2.
作者
谭伟
袁震
蒋进元
程永前
戴洪兴
TAN Wei;YUAN Zhen;IANG Jinyuan;CHENG Yongqian;DAI Hongxing(Chinese Research Academy of Environmental Sciences,Beijing 100012,China;College of Environmental and Energy Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《环境工程技术学报》
CAS
2018年第2期142-148,共7页
Journal of Environmental Engineering Technology
基金
国家水体污染控制与治理科技重大专项(2012ZX07201-005)
辽河等流域水体污染减排技术验证评估(ETV)与应用示范课题(014ZX07504003)
中国环境科学研究院中央级公益性科研院所基本科研业务专项(2015YSKY008)
