CAJ | 학술논문

采用溶胶-凝胶法制备 TiO2、ZrO2和不同比例 TiO2- ZrO2等载体,超声波浸渍负载一定量的 Ce- Mn 活性组分.通过扫描电镜、X 射线衍射、X 射线光电子能谱、傅里叶变换红外光谱和比表面积(BET)法对催化剂进行表征,并考察催化剂的氨气低温催化还原 NOx 的活性.结果表明,TiO2- ZrO2(3：1,摩尔比)载体为介孔材料,颗粒粒径较小且高度分散,比表面积高达151 m2·g -1.由于 Zr4+取代 Ti4+掺杂进入 TiO2晶格内,导致其晶格畸变,抑制 TiO2晶型转变,获得了良好的热稳定性,加之活性组分以无定形态存在,催化剂表面存在 Ce3+/ Ce4+氧化还原电对,从而提高催化剂的低温催化还原活性.在550℃下焙烧的催化剂10% Ce(0.4)- Mn/ TiO2- ZrO2(3：1)的活性最高,其在140℃、体积空速67000 h -1的条件下,NOx 的转化率达到99.28%.140℃时单独通入体积分数为10%的 H2 O 以及同时通入体积分数为10% H2 O 和2×10-4 SO2,催化剂显示出较强的抗 H2 O 和 SO2中毒能力.
채용용효-응효법제비 TiO2、ZrO2화불동비례 TiO2- ZrO2등재체,초성파침지부재일정량적 Ce- Mn 활성조분.통과소묘전경、X 사선연사、X 사선광전자능보、부리협변환홍외광보화비표면적(BET)법대최화제진행표정,병고찰최화제적안기저온최화환원 NOx 적활성.결과표명,TiO2- ZrO2(3：1,마이비)재체위개공재료,과립립경교소차고도분산,비표면적고체151 m2·g -1.유우 Zr4+취대 Ti4+참잡진입 TiO2정격내,도치기정격기변,억제 TiO2정형전변,획득료량호적열은정성,가지활성조분이무정형태존재,최화제표면존재 Ce3+/ Ce4+양화환원전대,종이제고최화제적저온최화환원활성.재550℃하배소적최화제10% Ce(0.4)- Mn/ TiO2- ZrO2(3：1)적활성최고,기재140℃、체적공속67000 h -1적조건하,NOx 적전화솔체도99.28%.140℃시단독통입체적분수위10%적 H2 O 이급동시통입체적분수위10% H2 O 화2×10-4 SO2,최화제현시출교강적항 H2 O 화 SO2중독능력.
Carriers of TiO2 , ZrO2 and TiO2-ZrO2 with different ratios were prepared by sol-gel method. Some manganese-cerium (Mn-Ce) active components were loaded on these carriers by ultrasonic immersion. The catalysts were characterized by scanning elec-tron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, and Brunauer-Emmett-Teller (BET) method. The activity of the catalysts was studied under the condition of low-temper-ature catalytic reduction of NOx with ammonia as a reductant. The results show that the TiO2-ZrO2 (3: 1, molar ratio) carrier was a me-soporous material, the particle size is smaller, the particles are highly dispersed, and the specific surface area reaches up to 151 m2· g - 1 . By doping ZrO2 , Zr4 + ions replace Ti4 + ions and enter the lattice, leading to TiO2 lattice distortion. The addition of ZrO2 inhibits crystal transfer from anatase to rutile phase, and so the thermal stability of this carrier improves. Furthermore, the active components mainly exist in amorphous state and the Ce3 + / Ce4 + redox couple appears on the carrier surface, thus the catalytic reduction activity at low temperature improves. The highest activity of the 10% Ce(0. 4)-Mn/ TiO2-ZrO2 (3: 1) catalyst is obtained under calcination at 550℃ . At 140 ℃ and a space velocity of 67000 h - 1 , the conversion rate of NOx reaches 99. 28% . The 10% Ce(0. 4)-Mn/ TiO2-ZrO2 (3: 1) catalyst provides strong anti-poisoning capacity to H2 O and SO2 in the presence of 10% H2 O alone, or 10% H2 O with 2 × 10 - 4 SO2 at 140 ℃ .