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V_2O_5-Sb_2O_3-TiO_2催化剂低温NH_3还原NO及其抗H_2O和SO_2毒化性能 认领 引用 被引量:6
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作者 曹政 黄妍 +1 位作者 彭莉莉 李建光 《燃料化学学报》 CSCD 北大核心 2012年第4期456-462,共7页
浸渍法制备了催化剂V2O5-Sb2O3-TiO2,考察了V2O5、Sb2O3负载量、pH值和焙烧温度对催化剂V2O5-Sb2O3-TiO2低温氨选择性催化还原(SCR)NO活性的影响;同时,考察了催化剂V2O5-Sb2O3-TiO2抗H2O和SO2毒化性能。结果表明,V2O5和Sb2O3负载量分别... 浸渍法制备了催化剂V2O5-Sb2O3-TiO2,考察了V2O5、Sb2O3负载量、pH值和焙烧温度对催化剂V2O5-Sb2O3-TiO2低温氨选择性催化还原(SCR)NO活性的影响;同时,考察了催化剂V2O5-Sb2O3-TiO2抗H2O和SO2毒化性能。结果表明,V2O5和Sb2O3负载量分别为5%和2%、焙烧温度为400℃、pH值为4时,催化剂SCR活性最好,反应温度220℃时,可达97%。Sb2O3的加入不仅能增强V2O5/TiO2的催化活性,而且能明显提高催化剂的抗H2O和SO2毒化性能。SO2、NO吸附暂态反应和TG-DTG测试表明,Sb2O3的促进机制主要是促进了催化剂在SO2存在条件下对NO的吸附,同时,减弱了硫酸铵盐与催化剂之间的相互作用,硫酸铵盐更容易分解。 展开更多
关键词 V2O5-Sb2O3-TiO2 低温 选择性催化还原 NO
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Effects of silica additive on the NH_3-SCR activity and thermal stability of a V_2O_5/WO_3-TiO_2 catalyst 认领 引用 被引量:24
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作者 刘雪松 吴晓东 +3 位作者 许腾飞 翁端 司知蠢 冉锐 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1340-1346,共7页
V2O5/WO3‐TiO2 and V2O5/WO3‐TiO2‐SiO2 catalysts were prepared by a wetness impregnation method, and both the catalysts were hydrothermally aged at 750℃ in 10 vol%H2O/air for 24 h. The catalysts were evaluated for N... V2O5/WO3‐TiO2 and V2O5/WO3‐TiO2‐SiO2 catalysts were prepared by a wetness impregnation method, and both the catalysts were hydrothermally aged at 750℃ in 10 vol%H2O/air for 24 h. The catalysts were evaluated for NOx conversion using NH3 as the reductant. Hydrothermal ageing decreased the NOx conversion of V2O5/WO3‐TiO2 catalyst severely over the entire measured tem‐perature range. Interestingly, the NH3‐SCR activity of the silica‐modified catalyst at 220–480℃ is enhanced after ageing. The catalysts were characterized by X‐ray diffraction, nitrogen adsorption, X‐ray fluorescence, Raman spectroscopy, H2 temperature‐programmed reduction, and NH3 temper‐ature‐programmed desorption. The addition of silica inhibited the phase transition from anatase to rutile titania, growth of TiO2 crystallite size and shrinkage of catalyst surface area. Consequently, the vanadia species remained highly dispersed and the hydrothermal stability of the V2O5/WO3‐TiO2 catalyst was significantly improved. 展开更多
关键词 V2O5/WO3-TiO2 Silica NH3-SCR Hydrothermal stability Polymeric vanadia De-NOx
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Thermal stability of Si-doped V2O5/WO3-TiO2 for selective catalytic reduction of NOx by NH3 认领 引用 被引量:15
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作者 Xun-Zhe Shao Hong-You Wang +5 位作者 Meng-Long Yuan Jie Yang Wang-Cheng Zhan Li Wang Yun Guo Guan-Zhong Lu 《Rare Metals》 SCIE EI CAS CSCD 2019年第4期292-298,共7页
The selective catalytic reduction of NOV with NH3 (NH3-SCR) is a very effective technology to control the emission of NOA, and the thermal stability of NH3-SCR catalyst is very important for removal of NOV from diesel... The selective catalytic reduction of NOV with NH3 (NH3-SCR) is a very effective technology to control the emission of NOA, and the thermal stability of NH3-SCR catalyst is very important for removal of NOV from diesel engines. In this work, V2O5/WO3-TiO2 (VWT) and SiO2- doped V2O5/WO3-TiO2 (VWTSi10)) catalysts were prepared by impregnation method and characterized by Brunauer- Emmett-Teller (BET), X-ray diffraction (XRD), Raman, temperature programmed reduction by hydrogen (H2-TPR), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption by ammonia (NH3- TPD). The doping of SiO2 promotes the thermal stability of V2O5/WO3-TiO? for NH3-SCR significantly. After calcination at 650 °C for 50 h, the operation window of 10% SiO2-doped V2O5/WO3-TiO2 is 220-480 °C, while the maximum NOV conversion on V2O5/WO3-TiO2 is about 77%. The presenee of SiO2 obviously blocks the transformation of TiO2 from anatase to rutile and stabilizes the dispersion of VOv and WO3 on the surface. It is available for the existence of V44 and the amount of surface acid sites increases, which inhabits the NH3 oxidation at the high temperature range and promotes NH3-SCR activity. 展开更多
关键词 V2O5/WO3-TiO2 SiO2 NH3-SCR Thermal stability
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负载型V_2O_5-WO_3/NiO-TiO_2脱硝催化剂上Ni组分的催化作用 认领 引用 被引量:13
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作者 赵梦梦 陈梦寅 +3 位作者 张鹏举 赵辉 唐富顺 阮乐 《粉末冶金工业》 CAS 北大核心 2019年第1期42-49,共8页
通过共沉淀法将Ni组分掺入到TiO_2载体中,并考察了不同NiO掺杂量对催化剂结构、表面性质与选择性催化还原(SCR)性能的影响。结果表明,NiO掺入到TiO_2中形成NiTiO_3,抑制了TiO_2晶粒的长大。Ni_3V_2O_8中孤立四面体VO_4的存在使催化剂表... 通过共沉淀法将Ni组分掺入到TiO_2载体中,并考察了不同NiO掺杂量对催化剂结构、表面性质与选择性催化还原(SCR)性能的影响。结果表明,NiO掺入到TiO_2中形成NiTiO_3,抑制了TiO_2晶粒的长大。Ni_3V_2O_8中孤立四面体VO_4的存在使催化剂表面Br?nsted酸含量减少,同时NiO_x与VO_x之间的相互作用降低了催化剂的可还原性,Ni_3V_2O_8中V4+的大量存在也不利于催化剂脱硝活性的提高。Ni组分以不当的方式渗入到V_2O_5-WO_3/TiO_2催化剂中对其具有毒化作用。 展开更多
关键词 NiTiO_x复合氧化物 V2O5-WO3/TiO2催化剂 掺杂 选择性催化还原 NO_x
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不同因素对V2O5-WO3-TiO2催化剂低温NO转化率的影响 认领 引用 被引量:4
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作者 梁全明 梁文俊 +3 位作者 樊星 宋丽云 李坚 何洪 《北京工业大学学报》 CAS CSCD 北大核心 2019年第7期699-709,共11页
考察不同V2O5负载量、O2体积分数、NO体积分数、SO2体积分数、H2O体积分数、n(NH3)(NO)、空速和在线加热再生等因素对浸渍法制备的V2O5-WO3/Ti O2催化剂低温NO转化率的影响.综合分析,选定V2O5最佳负载质量分数为3%,当反应温度为160℃时... 考察不同V2O5负载量、O2体积分数、NO体积分数、SO2体积分数、H2O体积分数、n(NH3)(NO)、空速和在线加热再生等因素对浸渍法制备的V2O5-WO3/Ti O2催化剂低温NO转化率的影响.综合分析,选定V2O5最佳负载质量分数为3%,当反应温度为160℃时,NO转化率为93. 7%. 110~320℃时,N2选择性大于98%,SO2氧化率低于1. 0%. NO转化率随O2体积分数增加而明显上升,随入口NO体积分数增加而有不同程度下降,但NOx去除量逐渐提高. n(NH3)(NO)≤1时,催化剂最优活性约等于各自n(NH3)(NO),n(NH3)(NO)> 1对催化剂活性没有明显提升.增大空速,催化剂高活性温区变窄,活性呈现不同程度的下降.表征结果表明,在含有SO2和H2O的选择性催化还原法(selective catalytic reduction,SCR)反应后,催化剂比表面积和孔容减小,活性组分流失,且沉积了包含NH4+和SO42-的副反应产物.热再生过程中催化剂延缓硫酸铵盐分解,导致催化剂抗中毒能力变差,活性难以恢复. 展开更多
关键词 非电行业 不同烟气条件 低温SCR V2O5-WO3/TiO2 在线加热再生
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V_2O_5-WO_3-TiO_2催化体系中V的取代对催化性能的影响 认领 引用 被引量:1
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作者 陶泽民 宋崇林 +3 位作者 吕刚 宾峰 张清茂 裴毅强 《燃烧科学与技术》 EI CAS 北大核心 2009年第6期535-540,共6页
采用浸渍法制备了不同比例Fe2O3和50%CuO、50%LaOx分别替代催化体系中V的V2O5-WO3-TiO2催化剂,并对其理化性能和催化活性进行了表征.结果表明:质量分数为9%的WO3能够保证500℃煅烧后的替代和未替代V2O5-WO3-TiO2催化剂具有较高的比表面... 采用浸渍法制备了不同比例Fe2O3和50%CuO、50%LaOx分别替代催化体系中V的V2O5-WO3-TiO2催化剂,并对其理化性能和催化活性进行了表征.结果表明:质量分数为9%的WO3能够保证500℃煅烧后的替代和未替代V2O5-WO3-TiO2催化剂具有较高的比表面积和较纯净的锐钛矿晶型,而氧化物替代对比表面积影响不大;当活性氧化物负载量的质量分数不高于3%时,Fe2O3替代对V2O5-WO3-TiO2催化剂的SCR催化性能影响不大;而LaOx替代使得催化剂的低温活性有所提高,同时高活性温度窗口也有一定程度的拓宽;CuO替代催化剂的活性明显低于其他几种催化剂;空气流速增加,Fe2O3替代催化剂的活性首先缓慢下降,在空气流速超过80 000 h-1以后,转化效率急速下降;水蒸气使Fe2O3替代催化剂的温度-转化率曲线向高温方向移动约50℃,但最高活性和高活性温度窗口变化不大. 展开更多
关键词 选择性催化还原 V2O5-WO3 -TiO2催化剂 Fe2O3 锐钛矿 催化活性
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Thermal Behavior and Lithium Ion Conductivity of L_2O-Al_2O_3-TiO_2-SiO_2-P_2O_5 Glass-ceramics 认领 引用 被引量:2
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作者 CHEN Hongping TAO Haizheng +1 位作者 WU Qide ZHAO Xiujian 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第1期67-72,共6页
A lithium ion conductive solid electrolyte, L20-AI203-TiO2-SiO2-P20s glass with NASICON- type structure have been synthesized and transformed into glass-ceramic through thermal-treatment at various temperatures from 7... A lithium ion conductive solid electrolyte, L20-AI203-TiO2-SiO2-P20s glass with NASICON- type structure have been synthesized and transformed into glass-ceramic through thermal-treatment at various temperatures from 700 to 1 000 ~C for 12 h. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance techniques were employed to characterize the samples. The experimental results indicated that the capability of glass forming in this system is superior to that of L20-A1203-TiO2-PzO~. The glass has an amorphous structure and resultant glass-ceramic mainly consisting of LiTi2(PO4)3 phases. Impurity phases AIPO4, TiO2, TiP207 and unidentified phase were observed. With the enhanced heat-treatment temperature, grain grew gradually and lithium ion conductivity of glass-ceramics increased accordingly, the related impedance semicircles were depressed gradually and even disappeared, which could be analytically explained by the coordinate action of the 'Constant phase element' (CPE) model and the 'Concept of Mismatch and Relaxation' model (CMR). When the sample is devitrified at 1 000 ~C, the maximum room temperature lithium ion conductivity comes up to 4.1 x 10-4 S/cm, which is suitable for the application as an electrolyte of all-solid-state lithium batteries. 展开更多
关键词 inorganic solid electrolyte glass-ceramic L2O-A12O3-TiO2-SiO2-P2O5 system LiTi2(PO4)3phase
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燃烧法V_2O_5-TiO_2催化3-甲基吡啶氧化性能的研究 认领 引用
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作者 田艳青 章斌 +4 位作者 葛军 郭伟 白秀全 孙晓芳 李文怀 《精细石油化工》 CAS 北大核心 2010年第5期13-16,共4页
研究了以燃烧法制备的V_2O_5-TiO_2催化剂用于3-甲基吡啶空气氧化制备烟酸的工艺过程。结果表明,该V_2O_5-TiO_2催化剂对3-甲基吡啶氧化制备烟酸的反应具有优异的催化性能。优化的反应条件为:温度280℃,3-甲基吡啶体积空速为0.2 h-1... 研究了以燃烧法制备的V_2O_5-TiO_2催化剂用于3-甲基吡啶空气氧化制备烟酸的工艺过程。结果表明,该V_2O_5-TiO_2催化剂对3-甲基吡啶氧化制备烟酸的反应具有优异的催化性能。优化的反应条件为:温度280℃,3-甲基吡啶体积空速为0.2 h-1,n(空气):n(水):n(3-甲基吡啶)=79:40:1,氧化产物烟酸的产率达到97.4%,纯度达99.0%。 展开更多
关键词 V2O5-TiO2 氧化 3-甲基吡啶 烟酸
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不锈钢板负载V_2O_5-WO_3-TiO_2催化剂制备及其催化还原脱硝性能 认领 引用 被引量:3
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作者 胡雍巍 谭蓉 银董红 《工业催化》 CAS 2012年第7期22-28,共7页
以溶胶-凝胶法制备的TiO2粉末为载体,偏钒酸铵和水合钨酸铵溶液为浸渍液,采用分步浸渍法制备了V2O5-WO3-TiO2催化剂,以聚乙烯醇-硅溶胶为黏合剂,采用涂覆法将催化剂粘合于经硫酸和钛酸丁酯溶胶处理过的不锈钢板板材表面,获得不锈钢板负... 以溶胶-凝胶法制备的TiO2粉末为载体,偏钒酸铵和水合钨酸铵溶液为浸渍液,采用分步浸渍法制备了V2O5-WO3-TiO2催化剂,以聚乙烯醇-硅溶胶为黏合剂,采用涂覆法将催化剂粘合于经硫酸和钛酸丁酯溶胶处理过的不锈钢板板材表面,获得不锈钢板负载的V2O5-WO3-TiO2催化剂。采用XRD、FT-IR和SEM等表征手段对催化剂进行表征,结果表明,V2O5-WO3-TiO2催化剂可均匀负载于不锈钢板表面。采用氨选择性催化还原氮氧化物法研究了催化剂的脱硝性能,结果表明,在空速8 000 L·(kg·h)-1和反应温度360℃的条件下,NOx脱除率超过92%,且制备的催化剂具有良好的稳定性和耐硫性。 展开更多
关键词 催化化学 V2O5-WO3-TiO2催化剂 不锈钢板 催化还原脱硝
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K2O对V2O5-WO3/TiO2催化剂的中毒作用 认领 引用 被引量:33
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作者 朱崇兵 金保升 +3 位作者 仲兆平 李锋 陈玲霞 翟俊霞 《东南大学学报(自然科学版)》 EI CAS 北大核心 2008年第1期101-105,共5页
实验室制备了V2O5-WO3/TiO2的脱硝催化剂,采用模拟中毒法,在此催化剂上负载碱金属氧化物K2O,通过BET,XRD,SEM等方法对微观结构进行表征.在SCR活性试验台上研究不同含量K2O对催化剂脱硝活性,N2O生成率和SO2氧化率的影响.结果发现:K2O对... 实验室制备了V2O5-WO3/TiO2的脱硝催化剂,采用模拟中毒法,在此催化剂上负载碱金属氧化物K2O,通过BET,XRD,SEM等方法对微观结构进行表征.在SCR活性试验台上研究不同含量K2O对催化剂脱硝活性,N2O生成率和SO2氧化率的影响.结果发现:K2O对于催化剂的毒性较强,随着添加量的增大,NO脱除率急剧下降,SO2的氧化率大大提高;较大含量的K2O(nKV=1,摩尔比)使催化剂比表面积有所减少,催化剂颗粒发生轻微团聚,微观结构变化不大,但NO的脱除率小于50%(380℃),N2O的生成率和SO2的氧化率均增加;K2O通过与V2O5的活性酸性位结合,使催化剂中有效活性位数量大为降低,导致脱硝活性下降. 展开更多
关键词 中毒 K2O V2O5-WO3/TiO2催化剂 SCR 脱硝
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商业V_2O_5-WO_3/TiO_2催化剂SCR脱硝过程中PM2.5的排放特性及影响因素研究 认领 引用 被引量:31
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作者 张玉华 束航 +2 位作者 范红梅 张亚平 杨林军 《中国电机工程学报》 EI CSCD 北大核心 2015年第2期383-389,共7页
针对V2O5-WO3/Ti O2商用催化剂,采用电称低压冲击器(ELPI)、PM10/PM2.5采样器、X-射线衍射(XRD)、场发射扫描电镜-能谱分析(FSEM-EDX)等对SCR烟气脱硝中形成的细颗粒粒径分布、形貌、元素及物相组成进行了测试分析,并研究了烟气组分及... 针对V2O5-WO3/Ti O2商用催化剂,采用电称低压冲击器(ELPI)、PM10/PM2.5采样器、X-射线衍射(XRD)、场发射扫描电镜-能谱分析(FSEM-EDX)等对SCR烟气脱硝中形成的细颗粒粒径分布、形貌、元素及物相组成进行了测试分析,并研究了烟气组分及反应条件对SCR脱硝系统出口细颗粒物性的影响。结果表明,SCR脱硝过程中会形成不少亚微米级颗粒,主要成分为硫酸铵以及硫酸氢氨,晶型呈块状。细颗粒生成量随反应温度的升高和NH3/NO摩尔比的增加而增加,在脱硝效率较高时,颗粒物形成量也趋于增多;烟气中SO2、H2O和O2浓度的增加均会导致细颗粒物形成量的增加。导致细颗粒物产生的主要原因可归结于催化剂的活性组分对SO2的氧化以及SCR脱硝反应中NH3的逃逸。 展开更多
关键词 选择性催化还原(SCR) PM2.5 形成 排放特性 影响因素 V2O5-WO3/TiO2
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Pr掺杂对V2O5-MoO3/TiO2催化剂NH3-SCR反应活性的影响 认领 引用 被引量:33
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作者 晁晶迪 何洪 +5 位作者 宋丽云 房玉娇 梁全明 张桂臻 邱文革 张然 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2015年第3期523-530,共8页
采用溶胶一凝胶法制备了不同Pr掺杂量的Pr6O11-TiO2载体,并以浸渍法制备了V2O5-MoO3/Pr6O11-TiO2催化剂.活性评价结果表明,该催化剂在220~400℃范围内具有良好的脱硝效率和N2选择性以及较强的抗SO2和H2O性能.表征结果表明,掺杂P... 采用溶胶一凝胶法制备了不同Pr掺杂量的Pr6O11-TiO2载体,并以浸渍法制备了V2O5-MoO3/Pr6O11-TiO2催化剂.活性评价结果表明,该催化剂在220~400℃范围内具有良好的脱硝效率和N2选择性以及较强的抗SO2和H2O性能.表征结果表明,掺杂Pr可以提高V2O5-MoO3/TiO2催化剂的比表面积、表面化学吸附氧物种浓度、桥式硝酸盐物种和Brionsted酸位数量,从而提高了催化剂上NHx的选择性催化还原(NH3-SCR)活性。 展开更多
关键词 Pr掺杂 V2O5-MoO3/TiO2催化剂 选择性催化还原 氨气
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NH_3 selective catalytic reduction of NO: A large surface TiO_2 support and its promotion of V_2O_5 dispersion on the prepared catalyst 认领 引用 被引量:12
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作者 刘欣 李俊华 +4 位作者 李想 彭悦 王虎 江晓明 王兰武 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第6期878-887,共10页
A titania support with a large surface area was developed, which has a BET surface area of 380.5 m^2/g, four times that of a traditional titania support. The support was ultrasonically impregnated with 5 wt% vanadia. ... A titania support with a large surface area was developed, which has a BET surface area of 380.5 m^2/g, four times that of a traditional titania support. The support was ultrasonically impregnated with 5 wt% vanadia. A special heat treatment was used in the calcination to maintain the large surface area and high dispersion of vanadium species. This catalyst was compared to a common V2O5-TiO2 catalyst with the same vanadia loading prepared by a traditional method. The new catalyst has a surface area of 117.7 m^2/g, which was 38% higher than the traditional V2O5-TiO2 catalyst. The selective catalytic reduction(SCR) performance demonstrated that the new catalyst had a wider temperature window and better N2 selectivity compared to the traditional one. The NO conversion was 80% from 200 to 450 °C. The temperature window was 100 °C wider than the traditional catalyst. Raman spectra indicated that the vanadium species formed more V-O-V linkages on the catalyst prepared by the traditional method. The amount of V-O-Ti and V=O was larger for the new catalyst. Temperature programmed desorption of NH3, temperature programmed reduction by H2 and X-ray photoelectron spectroscopy results showed that its redox ability and total acidity were enhanced. The results are helpful for developing a more efficient SCR catalyst for the removal of NOx in flue gases. 展开更多
关键词 V2O5-TiO2 catalyst Denitrification Titania Surface area Dispersibility
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V2O5-WO3/TiO2烟气脱硝催化剂的载体选择 认领 引用 被引量:50
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作者 朱崇兵 金保升 +2 位作者 仲兆平 李锋 翟俊霞 《中国电机工程学报》 EI 北大核心 2008年第11期41-47,共7页
在选择性催化还原试验台上对4种不同TiO2为载体制备的催化剂的脱硝性能进行测试,采用BET、X射线衍射、傅里叶转换红外光谱、扫描电镜-能谱分析、X射线荧光分析和热重分析等技术进行微观表征,并与商业催化剂进行对比。以硫酸法制备的纳... 在选择性催化还原试验台上对4种不同TiO2为载体制备的催化剂的脱硝性能进行测试,采用BET、X射线衍射、傅里叶转换红外光谱、扫描电镜-能谱分析、X射线荧光分析和热重分析等技术进行微观表征,并与商业催化剂进行对比。以硫酸法制备的纳米级锐钛型TiO2适合作为选择性催化还原催化剂载体,制备的催化剂脱硝效率高,温度窗口宽,选择性好,其中硫酸盐质量分数为8%~10%时最为有利;以氯化法制备纳米TiO2过程中,生成了V3Ti6O17的聚合物导致NO脱除率较低,因此不适合作为催化剂载体。以工业级TiO2为载体制备的催化剂氨氮比为1.0时,在355~420℃的温度范围内NO脱除率为80%~85%,但由于成本很低,因此可以用于脱硝要求不高的场合。由钛酸丁酯溶胶法制备TiO2为载体制备的SCR催化剂性能不及硫酸法制备的纳米级锐钛型TiO2制备的催化剂,且操作复杂,技术难度大,不适宜推广。 展开更多
关键词 V2O5-WO3/TiO2 催化剂载体 选择性催化还原 烟气脱硝 纳米级锐钛型TiO2
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Improving the denitration performance and K-poisoning resistance of the V_2O_5-WO_3/TiO_2 catalyst by Ce4+ and Zr4+ co-doping 认领 引用 被引量:22
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作者 Jun Cao Xiaojiang Yao +4 位作者 Fumo Yang Li Chen Min Fu Changjin Tang Lin Dong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第1期95-104,共10页
A series of V2O5‐WO3/TiO2‐ZrO2,V2O5‐WO3/TiO2‐CeO2,and V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalysts were synthesized to improve the selective catalytic reduction(SCR)performance and the K‐poisoning resistance of a V2O5‐W... A series of V2O5‐WO3/TiO2‐ZrO2,V2O5‐WO3/TiO2‐CeO2,and V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalysts were synthesized to improve the selective catalytic reduction(SCR)performance and the K‐poisoning resistance of a V2O5‐WO3/TiO2 catalyst.The physicochemical properties were investigated by using XRD,BET,NH3‐TPD,H2‐TPR,and XPS,and the catalytic performance and K‐poisoning resistance were evaluated via a NH3‐SCR model reaction.Ce^4+and Zr^4+co‐doping were found to enhance the conversion of NOx,and exhibit the best K‐poisoning resistance owing to the largest BET‐specific surface area,pore volume,and total acid site concentration,as well as the minimal effects on the surface acidity and redox ability from K poisoning.The V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst also presents outstanding H2O+SO2 tolerance.Finally,the in situ DRIFTS reveals that the NH3‐SCR reaction over the V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst follows an L‐H mechanism,and that K poisoning does not change the reaction mechanism. 展开更多
关键词 V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst Co‐doping K‐poisoning NH3‐SCR Reaction mechanism
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蜂窝状V_2O_5-WO_3/TiO_2催化剂脱硝性能研究 认领 引用 被引量:46
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作者 朱崇兵 金保升 +3 位作者 李锋 仲兆平 翟俊霞 陈玲霞 《中国电机工程学报》 EI 北大核心 2007年第29期45-50,共6页
实验室制备了蜂窝状V2O5-WO3/TiO2的脱硝催化剂,通过BET、XRD、SEM等方法对微观结构进行表征。在自制SCR活性试验台上测试各种运行工况(温度、空速比等)和烟气组成([NH3]/[NO]、水蒸气等)对催化剂的脱硝活性、选择性、SO,的氧... 实验室制备了蜂窝状V2O5-WO3/TiO2的脱硝催化剂,通过BET、XRD、SEM等方法对微观结构进行表征。在自制SCR活性试验台上测试各种运行工况(温度、空速比等)和烟气组成([NH3]/[NO]、水蒸气等)对催化剂的脱硝活性、选择性、SO,的氧化率和氨逃逸量的影响。研究结果表明,自制蜂窝状催化剂在空速比小于3500h^-1、NH3/NO在0.9-1.0、温度320-420℃范围内的NO脱除率较高、SO2氧化率和氨逃逸量较低,基本达到工业应用的要求;低含量(低于2%)水蒸气可以提高高温段NO脱除率,而高含量的水蒸气对催化剂NO脱除具有明显的抑制作用,但水蒸气的加入会使NO脱除温度范围拓宽;由于催化剂自身含有较多的硫酸盐,未观察到SO2对脱硝反应有促进作用。 展开更多
关键词 蜂窝状 V2O5-WO3/TiO2催化剂 选择性催化还原 脱硝
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Effect of Ce doping into V2O5-WO3/TiO2 catalysts on the selective catalytic reduction of NOx by NH3 认领 引用 被引量:27
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作者 Mengyin Chen Mengmeng Zhao +3 位作者 Fushun Tang Le Ruan Hongbin Yang Ning Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2017年第12期1206-1215,共10页
In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied compara... In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%(All Ce contents are in mass fractions), but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^(3+)species and more Br?nsted acid sites than that by impregnation. The vacancies caused by more Ce^(3+)species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br?nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts. 展开更多
关键词 V2O5-WO3/TiO2 catalysts Ce doping methods NH3 selective catalytic reduction NOx Dispersion state Reducibility Br?nsted acid sites
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Performance of V_2O_5-WO_3-MoO_3/TiO_2 Catalyst for Selective Catalytic Reduction of NO_x by NH_3 认领 引用 被引量:17
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作者 高岩 栾涛 +2 位作者 吕涛 程凯 徐宏明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期1-7,共7页
The V/O5-WO3-MoOy'TiO2 honeycomb catalyst was prepared with industrial grade chemicals. The structural and physico-chemical properties were analyzed with X-ray diffraction (XRD), scanning electron micrograph (SEM... The V/O5-WO3-MoOy'TiO2 honeycomb catalyst was prepared with industrial grade chemicals. The structural and physico-chemical properties were analyzed with X-ray diffraction (XRD), scanning electron micrograph (SEM) and mercury porosimetry. The NOx conversion and durability were investigated on a pilot plant test set under the actual operational conditions of a coal fired boiler. The catalyst monolith had good formability with mass per- centage of V : W : Mo : TiO2 : fiber glass = 1 : 4.5 : 4.5 : 72 : 18. Vanadium, tungsten and molybdenum species were highly dispersed on anatase TiO2 without causing the transformation of anatase TiO2 to ruffle by calcining under a current of air at 450℃ for 4.5 h, but there were some degrees of crystal distortion. The catalyst particle sizes were almost uniform with close pile-up and the pore structure was regular with complete macro-pore formation and large specific surface area. The NOx conversion was sensitive to temperature but nearly insensitive to NH3. The catalyst showed strong adaptability to NOx concentration with activity above 80% in the range of 615 1640 mg.m-3. Within the range of 720-8640 h continuous operation, the NOx conversion dropped at a rate of about 1% reduction per 600 h. 展开更多
关键词 selective catalytic reduction V2O5-WO3-MoO3/ZiO2 catalyst physico-chemical property flue gas life time
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纳米负载型V_2O_5-WO_3/TiO_2催化剂碱中毒及再生研究 认领 引用 被引量:51
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作者 沈伯雄 熊丽仙 +2 位作者 刘亭 王静 田晓娟 《燃料化学学报》 北大核心 2010年第1期85-90,共6页
实验制备了陶瓷颗粒为骨架的纳米级V2O5-WO3/TiO2(C)催化剂。采用浸渍法模拟碱金属中毒,研究了中毒及再生对催化剂脱硝活性的影响,运用XRD、FT-IR、H2-TPR、XPS技术表征分析了碱金属对催化剂的失活作用。实验表明,碱金属能使催化剂活性... 实验制备了陶瓷颗粒为骨架的纳米级V2O5-WO3/TiO2(C)催化剂。采用浸渍法模拟碱金属中毒,研究了中毒及再生对催化剂脱硝活性的影响,运用XRD、FT-IR、H2-TPR、XPS技术表征分析了碱金属对催化剂的失活作用。实验表明,碱金属能使催化剂活性降低,钾的毒性大于钠。FT-IR结果显示,催化剂以Lewis酸作为活性酸位。H2-TPR、XPS结果表明,钾的加入降低了催化剂的氧化能力,主要影响了催化剂表面的吸附氧。采用单纯的水洗方法并不能提高催化剂活性,而酸洗再生后催化剂在较高反应温度下活性得到较好的恢复。 展开更多
关键词 选择性催化还原 V2O5-WO3/TiO2 脱硝 碱金属 催化剂中毒 再生
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前驱体溶液pH值对V_2O_5-WO_3/TiO_2催化剂的低温NH_3-SCR性能的影响(英文) 认领 引用 被引量:26
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作者 董国君 张玉凤 +1 位作者 赵元 白洋 《燃料化学学报》 CSCD 北大核心 2014年第12期1455-1463,共9页
采用调节前驱体溶液pH值的方法制备了用于低温NH3-SCR的V2O5-WO3/Ti O2催化剂。通过XPS、Raman光谱、H2-TPR、NH3-TPD、NH3-DRIFT、XRD及物理吸附等手段对催化剂进行了表征分析,并对其脱硝催化活性进行了测试。结果表明,前驱体溶液酸性... 采用调节前驱体溶液pH值的方法制备了用于低温NH3-SCR的V2O5-WO3/Ti O2催化剂。通过XPS、Raman光谱、H2-TPR、NH3-TPD、NH3-DRIFT、XRD及物理吸附等手段对催化剂进行了表征分析,并对其脱硝催化活性进行了测试。结果表明,前驱体溶液酸性的增强能够提高催化剂表面聚合态钒物种和V4+(3+)/V5+的比值以及表面酸性,增加活性位数量、降低反应的活化能、提高其脱硝催化性能。因此,通过提高前驱体溶液的酸性,有助于制备出脱硝活性较好的NH3-SCR催化剂。 展开更多
关键词 前驱体溶液 V2 O5-WO3/TiO2 pH值 低温NH3-SCR 钒物种 脱硝活性
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