Ce掺杂对Mn-Co/TiO_2催化剂催化氧化NO的影响
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摘要
采用浸渍法制备Mn-Co-Ce/TiO2催化剂,考察Ce掺杂对催化剂催化氧化NO情况的影响。研究表明:在550℃焙烧下,Ce/Ti掺杂比为0.15时,催化剂具有最高的催化氧化活性。反应温度为250℃时,NO转化率可以高达85%;150℃时,转化率也可达到50%以上。BET与XRD结果表明,Ce掺杂改变了催化剂的比表面积、孔容积,并提高了活性组分的分散度。SO2和H2O的共同加入,使催化活性降低,发生不可逆中毒,但转化率在60%左右。
Mn-Co-Ce/TiO2 catalysts were prepared by impregnation method and the effect of Ce-doping on NO catalytic oxidation was tested.The samples with a Ce/Ti molar ratio of 0.15 and calcined at 550℃showed the best catalytic oxidation activity.The NO conversion was as high as 85% at the reaction temperature of 250℃;and it was still more than 50% at 150℃.As showed by BET and XRD,the excellent catalytic activity is mainly due to the high specific areas,pore structure and dispersion of the active species.When SO2 and H2O were present,the catalytic activity decreased,and when SO2 and H2O were off,the catalytic activity could not recover,but the NO conversion was still about 60%.
Mn-Co-Ce/TiO2 catalysts were prepared by impregnation method and the effect of Ce-doping on NO catalytic oxidation was tested.The samples with a Ce/Ti molar ratio of 0.15 and calcined at 550℃showed the best catalytic oxidation activity.The NO conversion was as high as 85% at the reaction temperature of 250℃;and it was still more than 50% at 150℃.As showed by BET and XRD,the excellent catalytic activity is mainly due to the high specific areas,pore structure and dispersion of the active species.When SO2 and H2O were present,the catalytic activity decreased,and when SO2 and H2O were off,the catalytic activity could not recover,but the NO conversion was still about 60%.
引文
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[2]宣小平,姚强.选择性催化还原法脱硝研究进展[J].煤炭转化,2002,25(3):26-31.
[3]吴忠标,蒋薪,赵伟荣.环境催化原理及应用[M].北京:化学工业出版社,2006.
[4]王辉,赵秀阁.NO在负载型金属氧化物催化剂上的氧化反应机理[J].华东理工大学学报:自然科学版,2001,27(1):6-10.
[5]鲁文质,赵秀阁,王辉,等.NO的催化氧化[J].催化学报,2000,21(5):423-427.
[6]LI H,TANG X,YI H,et al.Manganese-based Catalysts Supported on Titania for the Oxidation of Nitric Oxide[C].Power and Energy Engineering Conference.2009.APPEEC 2009.Asia-Pacific.IEEE,2009:1-4.
[7]陈霞,张俊丰,童志权,等.CuCoOx/TiO2催化氧化NO性能研究[J].环境工程学报,2009,3(5):869-874.
[8]HUANG J,TONG Z,HUANG Y,et al.Selective Catalytic Reduction of NO with NH3at Low Temperatures over Iron and Manganese Oxides Supported on Mesoporous Silica[J].Applied Catalysis B:Environ,2008,78(3):309-314.
[9]LI H,TANG X,YI H,et al.Low-temperature Catalytic Oxidation of NO over Mn-Ce-Oxcatalyst[J].J of Rare Earths,2010,28(1):64-68.
[10]夏斌,童志权,黄妍,等.CuSO4-CeO2/TS催化氧化NO及其抗H2O和SO2毒化性能[J].过程工程学报.2010,10(1):42-148.
[11]DING Z Y,LI L,WADE D,et al.Supercritical Water Oxidation of NH3 over a MnO2/CeO2Catalyst[J].Indust&Engin Chem Res.1998,37(5):1707-1716.
[12]MACHIDA M,UTO M,KUROGI D,et al.MnOxCeO2 Binary Oxides for Catalytic NOx Sorption at Low Temperatures.Sorptive Removal of NOx[J].Chem of mater.2000,12(10):3158-3164.
[13]罗晶,童志权,黄妍,等.H2O和SO2对Cr-Ce/TiO2催化氧化NO性能的影响[J].环境科学学报.2010,(5):1023-1029.
[14]MOCHIDA I,KISAMORI S,HIRONAKA M,et al.Oxidation of NO into NO2over Active Carbon Fibers[J].Energy&Fuels.1994,8(6):1341-1344.
[15]徐文青,赵俊,王海蕊,等.TiO2负载Mn-Co复合氧化物催化剂上NO催化氧化性能[J].物理化学学报.2013,29(2):385-390.