CAJ | 학술논문

用溶胶凝胶法制备了Mn-Ce/TiO2（用M表示）和Cu-Ce/TiO2（用C表示）催化剂，将M相、C相和V2O5-WO3（用V表示）用顺序浸渍法依次负载到堇青石蜂窝陶瓷载体（CC）上。用尿素选择性催化还原NOx（SCR）的转化率作为衡量指标对一系列的整体催化剂性能进行评价。催化剂的物理化学性能用N2吸附、CO2-TPD、NH3-TPD、XRD、XPS和H2-TPR等进行表征。结果表明，当M相优先于C相负载到CC上时，在0．01％SO2和10％H2 O存在的情况下，V/3C/3M/CC复合催化剂仍比C相或M相单独负载到堇青石上表现出较高的活性，并且微量的SO2有利于催化剂活性的提升。 XRD分析结果表明，Cu-Ce负载到TiO2溶胶上有助于锐钛矿相的形成，Mn-Ce负载到TiO2上有助于金红石相的形成。比表面积只与M或C相的负载量有关而与负载顺序无关。 M或C相能够增加催化剂表面不同强度的酸性位。 H2-TPR研究结果表明，V和Cu或Mn之间的相互作用提高了V的还原能力，进而增加了耗氢量。由XPS分析可知，催化剂表面较高的V4＋/V5＋比值和大量化学吸附氧的存在有利于催化剂活性的提升。
용용효응효법제비료Mn-Ce/TiO2（용M표시）화Cu-Ce/TiO2（용C표시）최화제，장M상、C상화V2O5-WO3（용V표시）용순서침지법의차부재도근청석봉와도자재체（CC）상。용뇨소선택성최화환원NOx（SCR）적전화솔작위형량지표대일계렬적정체최화제성능진행평개。최화제적물이화학성능용N2흡부、CO2-TPD、NH3-TPD、XRD、XPS화H2-TPR등진행표정。결과표명，당M상우선우C상부재도CC상시，재0．01％SO2화10％H2 O존재적정황하，V/3C/3M/CC복합최화제잉비C상혹M상단독부재도근청석상표현출교고적활성，병차미량적SO2유리우최화제활성적제승。 XRD분석결과표명，Cu-Ce부재도TiO2용효상유조우예태광상적형성，Mn-Ce부재도TiO2상유조우금홍석상적형성。비표면적지여M혹C상적부재량유관이여부재순서무관。 M혹C상능구증가최화제표면불동강도적산성위。 H2-TPR연구결과표명，V화Cu혹Mn지간적상호작용제고료V적환원능력，진이증가료모경량。유XPS분석가지，최화제표면교고적V4＋/V5＋비치화대양화학흡부양적존재유리우최화제활성적제승。
Mn-Ce/TiO2(M) and Cu-Ce/TiO2(C) were prepared by sol-gel method, and the cordierite honeycomb ceramics (CC) was coated with M and/or C and V2 O5-WO3 in sequence by impregnation method.A series of monolith catalysts were evaluated for the selective catalytic reduction (SCR) of NOx by urea.The physical and chemical properties of the catalysts were well examined using nitrogen adsorption, CO2-TPD, NH3-TPD, XRD, XPS and H2 -TPR experiments.The er sults showed that when the M phase was coated onto catalyst prior to C phase, the complex catalyst V/3C/3M/CC was more active than the catalysts with only M or C phase in the presence of 0.01%SO2 and 10%H2 O, and a small quantity of SO2 may favor the urea-SCR activity.XRD analysis indicated that Cu, Ce modified TiO2 sol favors the formation of anatase phase, and Mn, Ce modified TiO2 sol facilitates the formation of rutile phase.The BET surface area of catalyst only has relationship with the amount of M or C phase, and loading sequence does not influence it so much.The introduction of M phase and C phase icn reases the surface acid sites of different intensity.H2-TPR results showed the interaction between vanadium and copper and/or mangna ese species enhances the reduction of vanadium, which can increase the amount of H2 consumption.XPS results indicated that both high V4+/V5+ratio and large amount of surface chemisorbed oxygen may beneficial to the activity of the catalysts.