锆掺杂对Ti-Ce-Ox复合氧化物NH3选择性催化还原NO的影响

采用共混法制备Ti-Ce-Zr-Ox复合氧化物脱硝催化剂,主要研究究Ti-Ce-Zr-Ox复合氧化物催化剂NH3选择性催化还原[selective catalytic reduction(SCR),NH3-SCR]NO的活性,重点考察锆掺杂对Ti-Ce-Ox复合氧化物催化剂NH3-SCR脱除NO的影响.用X射线衍射、氮...     

Preparation and Performance of Al2 TiO5 -TiO2 -SiO2 Honeycomb Ceramics by Doping Rare Earth

A preferable honeycomb ceramics of Al2TiO5-TiO2-SiO2 doped by CeO2 and Er2O3 with high performance was prepared by means of extrusion molding and the effects of CeO2 and Er2O3 on the mechanical strength, thermal stability, and sintering temperature of ATS ceramics were mainly investigated. The experimental results and the microscopic analysis by scanning electron microscope, X-ray powder diffxaction, and TG-DSC showed that adding CeO2 and Er2O3 into ATS could prohibit the growth of their crystal grains and make their size uniform, which finally decrease its sintering temperature, and also enhance its mechanical performance as well as thermal stability. After the reforming, ATS doped by 0.5% CeO2 ＋0.5% Er2O3 was sintered at 1250 ℃, its bending strength reached to 177A MPa and thermal expansion coefficient was 3.8 ~ 10^-6/℃ at 25 - 1000℃, which provided a promising basis of making monolithic honeycomb catalyst of deNOx.     

Ce-Cu/Ti-Al-Ox催化氧化CO的性能研究

采用挤出成型法制备系列铜铈负载钛铝氧化物(Ce-Cu/Ti-Al-O_x)催化剂,研究Ce-Cu/Ti-Al-O_x催化氧化一氧化碳(CO)的性能,并对催化剂进行表征。结果表明:三氧化二铝(Al_2O_3)的掺入抑制了二氧化钛(TiO_2)的颗粒长大,不仅增大了催化剂的比表面积,同时提高了铜铈负载二氧化钛(Ce-Cu/TiO_2)催化剂的缺陷浓度,有利于催化剂表面反应气体的吸附以及催化反应的进行,因此适量添加Al_2O_3能明显提升Ce-Cu/TiO_2催化剂的低温催化氧化活性,拓宽其活性温度窗口,添加20%(wt,质量分数)Al_2O_3制得的Ce-Cu/Ti-Al-O_x催化剂具有对催化氧化CO的最好催化活性,在140℃条件下,活性达到了98%,170℃以上活性达到了100%。     

Al~(3+)掺入对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响

采用溶胶-凝胶法制备Al ~(3+)掺杂CeO_2(ZrO_2)/TiO_2催化剂,研究了Al ~(3+)掺入对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响。采用X射线衍射、氮气吸附脱附、氨气程序升温吸附、氢气程序升温还原以及荧光光谱等表征技术对催化剂进行表征。结果表明:Al ~(3+)的掺入有利于抑制TiO2从无定型相向锐钛矿相转变,增强了催化剂的储释氧性能,提高了催化剂的强酸酸量和缺陷浓度。强酸酸量和缺陷浓度的提高有利于反应气体的吸附;储释氧性能的增强,吸附的NO物种被氧化的速率加快,有利于催化反应的进行。因此,适量Al ~(3+)的掺入会明显提升CeO_2(ZrO_2)/TiO_2催化剂的高温脱硝活性,拓宽活性温度窗口。71400h-1条件下0.8Al-CZT催化剂在330℃达到最高活性(98.9%)且在400℃脱硝活性依然能够维持90.8%。     

蜂窝陶瓷载体介孔TiO2涂层的制备与表征

通过溶胶凝胶工艺制备ATS复相蜂窝陶瓷表面介孔TiO2涂层.研究了以冰醋酸为螫合剂的钛溶胶的优化配制,利用超声波振动测定涂层的结合强度,协同XRD、SEM及BET等显微表征手段对TiO2涂层进行微观分析和表征.实验表明:所制备的溶胶胶凝时间长、负载量大、比表面积大,500 ℃焙烧时,TiO2主要为锐钛矿晶型,介孔TiO2涂层与ATS复相蜂窝陶瓷具有高的结合强度.     

Ti-Zr-V-O/ATS复合脱硝催化剂的制备及其抗水性能研究

采用溶胶-凝胶法制备Ti-Zr-V-O复合脱硝催化剂。采用X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)及傅里叶红外光谱(FT-IR)等测试手段,分别对钛锆钒复合催化剂晶型、结晶形貌、组成及官能团结构等性能进行了分析表征。研究了H2O对催化剂选择性催化还原NO的影响。实验结果表明,Ti-Zr-V-O复合催化剂具有良好的脱硝催化活性和抗水性能。在空速为5 000 h-1时,反应温度240℃时,NO转化率达到96%;在10%的H2O作用下,Ti-Zr-V-O催化剂出现可逆水中毒现象,水蒸汽对低温脱硝活性具有抑制作用,对中高温催化活性具有促进作用。     

Y~(3+)和La~(3+)改性对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响

采用溶胶-凝胶法制备Y~(3+)和La~(3+)掺杂CeO_2(ZrO_2)/TiO_2(简称CZT)催化剂,研究Y~(3+)和La~(3+)掺入对其脱硝性能的影响。采用X射线衍射、氮气吸附脱附、氨气程序升温吸附、氢气程序升温还原以及紫外光光致发光光谱等实验方法对CZT催化剂进行表征。结果表明:Y~(3+)和La~(3+)的掺入抑制了TiO_2从无定形向锐钛矿型转变,不仅增大了催化剂的弱酸酸量和比表面积,同时提高了CZT催化剂的缺陷浓度和储释氧性能;弱酸酸量和比表面积的增大有利于CZT催化剂表面反应气体的吸附;缺陷浓度和储释氧性能的提高加快了吸附在CZT催化剂表面的NO被氧化速率,有利于催化反应的进行。因此,适量掺入Y~(3+)和La~(3+)会明显提升CZT催化剂的低温脱硝活性,拓宽其活性温度窗口。空速71 400 h-1条件下,0.2LaCZT催化剂在200℃的脱硝率达到85.1%,300℃达到最高(96.5%)。     

稀土掺杂Al_2TiO_5–TiO_2–SiO_2多相泡沫陶瓷的制备与性能

用有机先驱体浸渍法制备了CeO2和Er2O3等稀土掺杂的Al2TiO5–TiO2–SiO2多相泡沫陶瓷。研究了CeO2和Er2O3等稀土掺杂对Al2TiO5–TiO2–SiO2多相泡沫陶瓷力学性能的影响。结果表明:CeO2和Er2O3掺杂可以显著增强Al2TiO5–TiO2–SiO2多相泡沫陶瓷的抗弯强度,在1250℃,以质量分数为0.5?O2 0.5%Er2O3掺杂,陶瓷样品的抗弯强度最佳,达到177.4MPa;在50～1000℃,热膨胀系数为5.2×10–6/℃,显气孔率超过76%。     

Synergetic catalysis of ceria and titania for selective reduction of NO

The promotional effect of the interaction between titania and ceria on the catalytic performance for selective reduction of NO was studied.The catalysts,CeO 2,TiO 2,CeO 2 /TiO 2 and Ti x Ce 1-x O 2,were synthesized and tested in NH 3-Selective catalytic reduction(SCR) of NO,and the samples were characterized by the Brunaller,Emmett and Teller(BET absorbed gas N 2),X-ray diffraction(XRD),high resolution transmission electron microscopy(HR-TEM),and temperature programmed desorption(TPD NH 3) techniques.The improvement mechanism of the interaction between the titania and ceria had been explored and discussed from two aspects of micro-structure and surface acidity.The interaction between the titania and ceria greatly improved the catalytic activity but had little effect on the active temperature.It was first reported that the acid amount determined the catalytic activity and the acid strength determined the active temperature for NH 3-SCR of NO.     

A novel catalyst of silicon cerium complex oxides for selective catalytic reduction of NO by NH3

A series of CeO2/SiO2 and SixCe1-xO2 complex oxides supported on an activated Al2TiO5-TiO2-SiO2 complex phase (ATS) ceramics were prepared by step impregnation and co-impregnation methods, and characterized by N2-BET, XRD, SEM and NH3-TPD techniques. The effects of reaction temperature, CeO2/SiO2 loadings and Si/Ce molar ratio on the granular catalysts for NO selective catalytic reduction with ammonia (NH3-SCR) were studied. Results indicated that both CeO2/SiO2/ATS and CeO2/ATS catalysts showed the same ac...