介质阻挡放电协同V_(2)O_(5)/微孔TiO_(2)催化剂宽窗口脱硝

WIDE WINDOW DENITRIFICATION OF V_(2)O_(5)/MICROPOROUS TiO_(2) UNDER SYNERGISTIC EFFECT OF DIELECTRIC BARRIER DISCHARGE PLASMA

活性窗口窄是钒钛基催化剂在介质阻挡放电NH3选择性催化还原(SCR)中的关键限制因素之一。采用水热法制备的V_(2)O_(5)/微孔TiO_(2)催化剂,在介质阻挡放电的协同作用下具有明显的宽NH3-SCR活性窗口特征。通过对比空管、4V/TiO_(2)和该微孔载体钒钛催化剂室温下的催化性能,以及催化剂在N_(2)/O_(2)、N_(2)/O_(2)/NH3、N_(2)/O_(2)/NO气氛下的反应行为,分析了该催化剂的催化反应机理,对微孔载体催化剂进行了硫水耐受性测试,并采用XRD、SEM、BET、XPS、TGA、FTIR等方法对材料的微观形貌结构特征等进行了分析。结果表明:4V/MP-TiO_(2)催化剂的脱硝效率较常规钒钛催化剂提高了33.68%,在243~442 J/L内均能保持80%以上的脱硝效率,在降低能耗的同时具有良好的耐硫、水性能。这是由于微孔TiO_(2)整体结构疏松,具有丰富的孔结构,改善了载体的孔容,提高了催化剂的分散性,为NH3提供了更多的活性吸附位点,有利于拓宽活性窗口,同时微孔TiO_(2)提高了催化剂氧化NO的能力,有助于高能量密度区间快速SCR反应的进行。

The narrow active window is one of the key limitations for vanadium-titanium based catalysts in selective catalytic reduction of NOx with NH3 under dielectric barrier discharge.The V_(2)O_(5)/microporous TiO_(2) catalyst prepared by the hydrothermal method exhibited obvious wide NH3-SCR active window characteristics under the synergistic effect of dielectric barrier discharge.By comparing the catalytic performance of empty tubes,4V/TiO_(2),and the vanadium-titanium based catalyst with the microporous carrier at room temperature,as well as the reaction behavior of the catalyst in N_(2)/O_(2),N_(2)/O_(2)/NH3,N_(2)/O_(2)/NO atmosphere,the catalytic reaction mechanism of the catalyst was analyzed.The sulfur and water resistance of the microporous-carrier catalyst was tested,and the microstructure of the material was analyzed by XRD,SEM,BET,XPS,TGA and FTIR.The results showed that the denitrification efficiency of the 4V/MP-TiO_(2) catalyst was increased by 33.68%compared to conventional vanadium-titanium catalysts,and it maintained a denitrification efficiency of more than 80%in the range of 243 J/L to 442 J/L.It has good sulfur and water resistance while reducing energy consumption.This is due to the loose overall structure of microporous TiO_(2),which has a rich pore structure,improving the pore volume of the carrier,as well as the dispersion of the catalyst,and more active adsorption sites for NH3,which is conducive to broadening the active window.At the same time,microporous TiO_(2) enhances the ability of the catalyst to oxidize NO,which facilitates the rapid SCR reaction when the specific input energy is high.