CAJ | 학술논문

采用后合成法制备MnOx/Al-SBA-15催化剂,考察了催化剂的低温NH3选择性催化还原(SCR)NOx的性能.利用傅里叶变换红外(FTIR)光谱、N2吸附-脱附、X射线衍射(XRD)、扫描电镜(SEM)、拉曼(Raman)光谱、X射线光电子能谱(XPS)及NH3程序升温脱附(NH3-TPD)的表征手段,对催化剂的结构性质和SCR性能进行了系统分析.结果表明,适量Al的掺杂能提高MnOx/SBA-15催化剂的SCR活性,当硅铝摩尔比为50时,催化剂活性最佳.表征结果显示, Al掺杂后,催化剂仍保持良好的骨架结构,较大比表面积、孔容和孔径,并且Mn在催化剂表面富集,由低价态转化为高价态, MnO2为催化剂的主要活性相.此外, Al的掺杂使MnOx在催化剂表面高度分散,表面酸性增强,从而提高了催化剂的SCR活性.
채용후합성법제비MnOx/Al-SBA-15최화제,고찰료최화제적저온NH3선택성최화환원(SCR)NOx적성능.이용부리협변환홍외(FTIR)광보、N2흡부-탈부、X사선연사(XRD)、소묘전경(SEM)、랍만(Raman)광보、X사선광전자능보(XPS)급NH3정서승온탈부(NH3-TPD)적표정수단,대최화제적결구성질화SCR성능진행료계통분석.결과표명,괄량Al적참잡능제고MnOx/SBA-15최화제적SCR활성,당규려마이비위50시,최화제활성최가.표정결과현시, Al참잡후,최화제잉보지량호적골가결구,교대비표면적、공용화공경,병차Mn재최화제표면부집,유저개태전화위고개태, MnO2위최화제적주요활성상.차외, Al적참잡사MnOx재최화제표면고도분산,표면산성증강,종이제고료최화제적SCR활성.
A series of MnOx/Al-SBA-15 catalysts were prepared by post synthesis methods for low-temperature selective catalytic reduction (SCR) of NOx with NH3. Structural properties and catalytic performance were comprehensively characterized by Fourier transform infrared (FTIR) spectroscopy, N2 adsorption-desorption, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and temperature programmed desorption of NH3 (NH3-TPD). The results showed that moderate addition of Al improved the SCR activity of the MnOx/SBA-15 catalyst, and the MnOx/Al-SBA-15 catalyst with nSi/nAl=50 had the highest activity. Characterization results revealed that the doped material MnOx/Al-SBA-15 catalysts maintained high specific surface area, large pore volume, and uniform pore size. Al doping improved the concentration and valence state of Mn, where MnO2 was determined to be the main active phase. Owing to a high dispersion of MnOx and a stronger surface acidity, the MnOx/Al(50)-SBA-15 catalyst exhibited higher SCR activity.