CAJ | 학술논문

氮氧化物(NOx)是大气主要污染物之一,主要来源于化石燃料的燃烧,其中NO不溶于水难以去除,催化氧化技术可以将NO氧化为易溶于水可被脱硫装置去除的NO2,具有十分重要的实际意义.本文采用浸渍法制备了不同Mn掺杂量的Mn-Co/TiO2复合金属氧化物催化剂,考察了其催化NO氧化的活性.结果表明, Mn的掺杂对Co/TiO2催化剂催化NO氧化的活性有明显促进作用,掺杂量为6%时, Mn(0.3)-Co(0.7)/TiO2催化剂NO的转化效率最高,300°C达到88%.采用X射线衍射(XRD)、N2吸附/脱附、H2程序升温还原(H2-TPR)、O2程序升温脱附(O2-TPD)和原位漫反射傅里叶变换红外(in-situ DRFTIR)光谱等技术对催化剂的物理化学特征进行了表征.结果发现,当掺杂量为6%时, Mn一方面促进了催化剂表面活性组分的分散,增加了催化剂的比表面积和孔径;另一方面提高了催化剂的还原性能,促进氧的低温脱附,此外还促进了反应中间产物桥式NO-3向NO2的反应,从而提高了Co/TiO2催化剂的NO氧化活性.
담양화물(NOx)시대기주요오염물지일,주요래원우화석연료적연소,기중NO불용우수난이거제,최화양화기술가이장NO양화위역용우수가피탈류장치거제적NO2,구유십분중요적실제의의.본문채용침지법제비료불동Mn참잡량적Mn-Co/TiO2복합금속양화물최화제,고찰료기최화NO양화적활성.결과표명, Mn적참잡대Co/TiO2최화제최화NO양화적활성유명현촉진작용,참잡량위6%시, Mn(0.3)-Co(0.7)/TiO2최화제NO적전화효솔최고,300°C체도88%.채용X사선연사(XRD)、N2흡부/탈부、H2정서승온환원(H2-TPR)、O2정서승온탈부(O2-TPD)화원위만반사부리협변환홍외(in-situ DRFTIR)광보등기술대최화제적물이화학특정진행료표정.결과발현,당참잡량위6%시, Mn일방면촉진료최화제표면활성조분적분산,증가료최화제적비표면적화공경;령일방면제고료최화제적환원성능,촉진양적저온탈부,차외환촉진료반응중간산물교식NO-3향NO2적반응,종이제고료Co/TiO2최화제적NO양화활성.
Global y, NOx is one of the most widespread pol utants. It is generated mainly from the burning of fossil fuels, and NO is very difficult to remove because of its capacity to be dissolved in water. The catalytic oxidation method can be used to convert NO to NO2, which is soluble in water and can be removed using desulfurization devices. Here, a series of TiO2-supported Mn-Co composite oxide catalysts were prepared using the impregnation method. The results of catalytic activity tests showed that the addition of Mn enhanced the efficiency of NO oxidation. Significantly, with 6% doping amounts, Mn (0.3)-Co(0.7)/TiO2 showed the best activity of 88% NO conversion at 300 °C. X-ray diffraction (XRD), N2 adsorption/desorption, hydrogen temperature-programmed reduction (H2-TPR), oxygen temperature-programmed desorption (O2-TPD), and in-situ diffuse reflectance Fourier transform infrared (in-situ DRFTIR) spectroscopy were used to characterize the catalysts. The results indicated that when the doping amount was 6% , the Mn enhanced the specific surface areas and pore volumes, which improved the dispersion of the active component over the TiO2 support. The co-doping of manganese into the Co/TiO2 also enhanced the oxygen desorption capabilities of the catalysts, which improved their reduction abilities. In addition, bridge NO-3, the key intermediate, was converted into NO2; this conversion was also enhanced by the presence of Mn on the Co/TiO2 catalyst. Al of the above reasons account for the high NO catalytic oxidation activity of the supported Mn-Co composite oxide catalysts.