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SO_2 poisoning and regeneration of Mn-Ce/TiO_2 catalyst for low temperature NO_x reduction with NH_3 认领 引用 被引量:37
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作者 盛重义 胡宇峰 +2 位作者 薛建明 王小明 廖伟平 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第7期676-682,共7页
SO2 poisoning and regeneration of Mn-Ce/TiO2 catalyst prepared by a novel co-precipitation method for low temperature selective catalytic reduction (SCR) of NOx with ammonia were investigated in this study. When 700... SO2 poisoning and regeneration of Mn-Ce/TiO2 catalyst prepared by a novel co-precipitation method for low temperature selective catalytic reduction (SCR) of NOx with ammonia were investigated in this study. When 700 ppm SO2 was fed in, the Mn-Ce/TiO2 catalyst had good resistance to SO2, but the deactivation of Mn-Ce/TiO2 poisoned by SO2 still occurred. The NO conversion of Mn-Ce/TiO2 (the molar ra-tio of Ce to Ti is 0.075) catalyst decreased from 92.5% to 34.6% in 13 h. Characterizations of fresh and SO2-poisoned Mn-Ce/TiO2 catalysts were carried out by Brunauer-Emmett-Teller method (BET), ion chromatography (IC), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The characterized results indicated that the deposition of sulfates and nitrates on the surface made the catalyst deactivated. Water washing, thermal regeneration and reductive regeneration were used to regenerate the deactivated Mn-Ce/TiO2. And water washing showed best performance on the regeneration of poisoned catalysts, especially with ultrasonic vibration. The Mn-Ce/TiO2 catalyst showed high stability under a series of deactivation-regeneration experiments for ten cycles. 展开更多
关键词 low temperature SCR Mn-Ce/TiO2 deactivation regeneration water washing rare earths
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Distinct effect of preparation methods on reaction efficiency of Mn-Ce/Al2O3 catalysts in low-temperature NH3-SCR 认领 引用 被引量:8
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作者 Shijie Hao Yandi Cai +7 位作者 Wei Wei Yanan Lv Jiawei Ji Wei Tan Jingfang Sun Liwei Jia Changjin Tang Lin Dong 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第10期1865-1872,共8页
In this study,a series of Mn-Ce/Al2O3 catalysts was prepared by different methods of depositionprecipitation(MnCeAl-DP),impregnation(MnCeAl-IM) and citric acid(MnCeAl-CA),and the distinct effect of preparation m... In this study,a series of Mn-Ce/Al2O3 catalysts was prepared by different methods of depositionprecipitation(MnCeAl-DP),impregnation(MnCeAl-IM) and citric acid(MnCeAl-CA),and the distinct effect of preparation methods on NOx removal performance at low temperature was explored.Results show that MnCeAl-DP exhibits not only the best activity but also the highest resistance against SO2/H2O.With the assistance of comprehensive characterizations from scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET),X-ray diffraction(XRD),H2-temperature programmed reduction(H2-TPR),NH3-te mperature programmed deso rption(NH3-TPD),and X-ray photoelectron spectroscopy(XPS),it is revealed that the MnCeAl-DP sample owns admired features of large surface area and pore volume,enriched Mn4+ and chemisorbed oxygen species originating from enhanced interaction between MnO_x and CeO2,as well as improved adsorption capacity to NH3 and NO.All these factors contribute to activity enhancement.Further in-situ DRIFTS studies reveal that the improvement of NH3-SCR performance over MnCeAI-DP is related to the formation of abundant nitrate species,which is beneficial to the "NH4NO3" reaction pathway and thus enhances low-temperature activity. 展开更多
关键词 Mn-Ce/Al2O3catalysts NH3-SCR Low temperature NH4NO3 Fast SCR Rare earths
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SO_2对Mn-Ce/TiO_2低温SCR催化剂的毒化作用研究 认领 引用 被引量:18
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作者 闫东杰 玉亚 +2 位作者 黄学敏 刘树军 刘颖慧 《燃料化学学报》 CSCD 北大核心 2016年第2期232-238,共7页
考察了SO_2对Mn-Ce/TiO_2低温脱硝催化剂活性的影响,利用XRD、BET、SEM和XPS对其毒化作用的原因进行分析。结果表明,SO_2对催化剂活性有明显的抑制作用,使NO_x去除率由84%降至42%左右。主要是SO_2的加入造成催化剂比表面积减小,孔径为5-... 考察了SO_2对Mn-Ce/TiO_2低温脱硝催化剂活性的影响,利用XRD、BET、SEM和XPS对其毒化作用的原因进行分析。结果表明,SO_2对催化剂活性有明显的抑制作用,使NO_x去除率由84%降至42%左右。主要是SO_2的加入造成催化剂比表面积减小,孔径为5-10 nm的孔数量减少,且催化剂晶相由锐钛矿型转化成金红石型结构,活性组分MnO_x发生晶化现象,破坏了Mn-Ti间的强相互作用。催化剂理化性质的变化造成吸附态氧转化为晶格氧的路径受阻、MnO_2含量减少和CeO_x储氧功能减弱,并且产生氧阻效应而使NO吸附和解吸受阻,造成催化剂活性降低。同时生成的硫酸铵盐在催化剂表面沉积,覆盖了催化剂表面的Lewis酸性位,使其对NH_3吸附能力减弱。 展开更多
关键词 低温SCR Mn-Ce/TiO2催化剂 SO2 毒化作用
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铁钴共掺杂的Mn-Ce/TiO_2催化剂低温SCR脱硝 认领 引用 被引量:17
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作者 朱少文 沈伯雄 +1 位作者 池桂龙 张笑 《环境工程学报》 CAS CSCD 北大核心 2017年第6期3633-3639,共7页
采用浸渍法制备了Fe和Co改性的Mn-Ce/TiO_2催化剂,研究了Fe和Co共同掺杂对催化剂脱硝及抗水抗硫性的影响。发现Fe和Co以1∶2摩尔比共同掺杂的催化剂具有最佳的脱硝活性。通过BET、XRD、XPS和FTIR等表征手段对其微观结构和抗毒性机理进... 采用浸渍法制备了Fe和Co改性的Mn-Ce/TiO_2催化剂,研究了Fe和Co共同掺杂对催化剂脱硝及抗水抗硫性的影响。发现Fe和Co以1∶2摩尔比共同掺杂的催化剂具有最佳的脱硝活性。通过BET、XRD、XPS和FTIR等表征手段对其微观结构和抗毒性机理进行研究,发现Fe和Co的掺杂能明显提高催化剂的比表面积和孔隙率,增强催化剂的氧化还原性能。Fe和Co的引入还能减少硫酸根离子和水分子在催化剂表面的累积,从而增强催化剂的抗水抗硫性能。 展开更多
关键词 低温SCR 铁钴 共掺杂 锰铈钛 催化剂
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Ni,Co掺杂对Mn-Ce/TiO_2催化剂脱硝活性的影响 认领 引用 被引量:10
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作者 吴彦霞 梁海龙 +2 位作者 陈鑫 赵春林 唐婕 《化工环保》 CAS CSCD 北大核心 2016年第3期321-325,共5页
以Ti O_2为载体,采用浸渍法制备Ni或Co掺杂的Mn-Ce/Ti O_2催化剂,用于烟气的选择性催化还原法低温脱硝。考察Ni或Co的掺加对Mn-Ce/Ti O_2催化剂活性的影响,并对各催化剂进行了BET,XRD,H_2-TPR,XPS表征。实验结果表明:在NO,NH_3,O_2的体... 以Ti O_2为载体,采用浸渍法制备Ni或Co掺杂的Mn-Ce/Ti O_2催化剂,用于烟气的选择性催化还原法低温脱硝。考察Ni或Co的掺加对Mn-Ce/Ti O_2催化剂活性的影响,并对各催化剂进行了BET,XRD,H_2-TPR,XPS表征。实验结果表明:在NO,NH_3,O_2的体积分数分别为6×10-4,6×10-4,6×10-2,空速为16 000 h-1的条件下,Mn-Ce/Ti O_2、Mn-Ce-Ni0.4/Ti O_2和Mn-Ce-Co0.2/Ti O_2催化剂的NO去除率在120℃时分别为38%,68%,74%,在150℃时分别为64%,92%,近100%,这表明掺加Ni或Co后Mn-Ce/Ti O_2催化剂的脱硝活性明显提高;在进气中加入体积分数为1×10-4的SO_2后,Mn-Ce/Ti O_2催化剂的NO去除率在300 min内从98.2%下降至57.2%,而Mn-CeCo0.2/Ti O_2和Mn-Ce-Ni0.4/Ti O_2催化剂的NO去除率分别为73.9%和69.8%,这表明Ni或Co的掺加有助于提高催化剂的抗硫性能。表征结果表明:Ni或Co的掺加基本不影响Mn和Ce在载体Ti O_2上的分散;Ce元素以Ce3+和Ce4+价态存在,且主要为Ce4+;催化剂的比表面积变化不大;Mn O_x与Ce O_x的结晶度降低,催化剂的氧化还原能力增强。 展开更多
关键词 低温脱硝 选择性催化还原 催化剂 Mn-Ce/TiO2 掺杂
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Mn-Ce-Fe/TiO2低温催化还原NO的性能 认领 引用 被引量:26
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作者 寻洲 童华 +1 位作者 黄妍 童志权 《环境科学学报》 CAS 北大核心 2008年第9期1733-1738,共6页
采用浸渍法制备了Mn-Ce-Fe/TiO2,研究了其组分配比、焙烧温度等制备条件和NO进口浓度、空速、O2含量、NH3/NO摩尔比等操作条件对Mn-Ce-Fe/TiO2上NH3低温还原NO活性的影响,并探讨了H2O、SO2对Mn-Ce-Fe/TiO2活性的影响.结果表明,Mn∶Fe∶C... 采用浸渍法制备了Mn-Ce-Fe/TiO2,研究了其组分配比、焙烧温度等制备条件和NO进口浓度、空速、O2含量、NH3/NO摩尔比等操作条件对Mn-Ce-Fe/TiO2上NH3低温还原NO活性的影响,并探讨了H2O、SO2对Mn-Ce-Fe/TiO2活性的影响.结果表明,Mn∶Fe∶Ce摩尔比为5∶2∶4、500℃下焙烧的Mn-Ce-Fe/TiO2在无H2O、SO2,NO体积分数为0.1%,空速为5000h-1,反应温度为130℃、O2含量为6%、NH3/NO摩尔比为1.1的条件下,NO转化率接近98%.Fe的加入大大提高了催化剂的单独抗水和同时抗硫抗水性能,130℃下,体积分数10%的H2O对该催化剂的活性基本没有影响,转化率保持在96%以上;通硫、水后的400min内,活性仅下降3%.单独通入SO2时,该催化剂中毒程度较深.该催化剂有望应用于基本不含SO2的燃气锅炉烟气和不含SO2的硝酸尾气等NOx工业废气的低温脱硝. 展开更多
关键词 Mn Ce Fe TiO2 NO 低温催化
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Ho-modified Mn-Ce/TiO_2 for low-temperature SCR of NO_x with NH_3:Evaluation and characterization 认领 引用 被引量:29
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作者 Wei Li Cheng Zhang +4 位作者 Xin Li Peng Tan Anli Zhou Qingyan Fang Gang Chen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第10期1653-1663,共11页
Low‐temperature selective catalytic reduction(SCR)of NO with NH3 was tested over Ho‐doped Mn–Ce/TiO2 catalysts prepared by the impregnation method.The obtained catalysts with different Ho doping ratios were charact... Low‐temperature selective catalytic reduction(SCR)of NO with NH3 was tested over Ho‐doped Mn–Ce/TiO2 catalysts prepared by the impregnation method.The obtained catalysts with different Ho doping ratios were characterized by Brunauer‐Emmett‐Teller(BET),X‐ray diffraction(XRD),temperature‐programmed reduction(H2‐TPR),temperature‐programmed desorption of NH3(NH3‐TPD),X‐ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).The catalytic activities were tested on a fixed bed.Their results indicated that the proper doping amount of Ho could effectively improve the low‐temperature denitrification performance and the SO2 resistance of Mn–Ce/TiO2 catalyst.The catalyst with Ho/Ti of 0.1 presented excellent catalytic activity,with a conversion of more than 90%in the temperature window of 140–220°C.The characterization results showed that the improved SCR activity of the Mn–Ce/TiO2 catalyst caused by Ho doping was due to the increase of the specific surface area,higher concentration of chemisorbed oxygen,higher surface Mn4+/Mn3+ratio,and higher acidity.The SO2 resistance test showed that the deactivating influence of SO2 on the catalyst was irreversible.The XRD and XPS results showed that the main reason for the catalyst deactivation was sulfates that had formed on the catalyst surface and that Ho doping could inhibit the sulfation to some extent. 展开更多
关键词 Mn–Ce–Ho/TiO2 Low‐temperature selective catalytic reduction Catalyst Holmium SO2
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Ho掺杂对Mn-Ce/TiO_2低温SCR催化剂的脱硝性能影响 认领 引用 被引量:6
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作者 李伟 张成 +3 位作者 李鑫 谭鹏 方庆艳 陈刚 《燃料化学学报》 CSCD 北大核心 2017年第12期1508-1513,共6页
采用浸渍法制备了五种掺杂不同比例的Ho的低温选择性催化还原(SCR)催化剂Mn0.4Ce0.07Hox/TiO_2。研究了Ho的引入对于Mn-Ce/TiO_2催化剂低温脱硝性能的影响,并采用XPS、XRF、BET、XRD、NH3-TPD等手段对催化剂的物理化学性质进行表征。结... 采用浸渍法制备了五种掺杂不同比例的Ho的低温选择性催化还原(SCR)催化剂Mn0.4Ce0.07Hox/TiO_2。研究了Ho的引入对于Mn-Ce/TiO_2催化剂低温脱硝性能的影响,并采用XPS、XRF、BET、XRD、NH3-TPD等手段对催化剂的物理化学性质进行表征。结果表明,掺杂适量的Ho能够有效提高Mn-Ce/TiO_2催化剂的低温脱硝性能,当Ho/Ti掺杂比例为0.1时催化剂Mn0.4Ce0.07Ho0.1/TiO_2活性表现最佳,在200℃左右催化效率达到最高,为91.17%,在140-240℃催化效率达到80%以上。结果表明,Ho的掺杂能够增大催化剂的比表面积,提高催化剂化学吸附氧的浓度以及Ce的附着量。 展开更多
关键词 选择性催化还原(SCR) Ho 催化剂 Mn-Ce/TiO2
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锑掺杂对Mn-Ce/TiO2催化剂脱硝性能的影响 认领 引用 被引量:2
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作者 王献忠 吴彦霞 +5 位作者 梁海龙 陈鑫 陈琛 晏根平 戴长友 陈玉峰 《石油炼制与化工》 CAS CSCD 北大核心 2021年第2期67-72,共6页
采用浸渍法制备了一系列Sb掺杂的Mn-Ce-Sb/TiO2催化剂,考察了Sb/TiO2摩尔比对催化剂脱硝性能的影响,采用X射线衍射、N 2吸附-脱附、NH 3程序升温脱附、H 2程序升温还原等表征手段对Mn-Ce/TiO2和Mn-Ce-Sb/TiO2(Sb/TiO2摩尔比2∶10)催化... 采用浸渍法制备了一系列Sb掺杂的Mn-Ce-Sb/TiO2催化剂,考察了Sb/TiO2摩尔比对催化剂脱硝性能的影响,采用X射线衍射、N 2吸附-脱附、NH 3程序升温脱附、H 2程序升温还原等表征手段对Mn-Ce/TiO2和Mn-Ce-Sb/TiO2(Sb/TiO2摩尔比2∶10)催化剂进行表征,并对两种催化剂的脱硝性能、抗硫和抗水性能进行对比。结果表明:Sb的掺杂有利于催化剂的活性组分在载体上更好地分散,促进活性组分与载体之间的相互作用,促进低温氧化还原反应的进行;Mn-Ce-Sb/TiO2催化剂具有较大的比表面积、较多的表面酸性位及优良的氧化还原性能,因此,与Mn-Ce/TiO2催化剂相比,Mn-Ce-Sb/TiO2催化剂具有更高的选择性催化还原NO活性及较好的抗硫、抗水性能。 展开更多
关键词 锑掺杂 Mn-Ce/TiO2催化剂 脱硝 抗硫 抗水
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Novel promoting effects of cerium on the activities of NO_x reduction by NH_3 over TiO_2-SiO_2-WO_3 monolith catalysts 认领 引用 被引量:15
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作者 房志涛 林涛 +3 位作者 徐海迪 吴干学 孙萌萌 陈耀强 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第10期952-959,共8页
A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic re... A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic reduction(SCR) performance and SO2-resistant ability of TiO2-SiO2-WO3 were greatly enhanced by the introduction of cerium. The catalyst containing 10% CeO2 showed the highest NO conversion in a wide temperature range and good N2 selectivity with broad operation temperature window at the gas hourly space velocity(GHSV) of 30000 h–1, which was a very promising catalyst for NOx abatement from diesel engine exhaust. The catalysts were characterized by X-ray diffraction(XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy(SEM-EDS), N2 adsorption-desorption(BET) and X-ray photoelectron spectroscopy(XPS). The characterization results showed that the bigger pore radius, higher surface atomic concentration and dispersion of Ce and the abundant adsorbed oxygen on the surface of catalyst contributed to the best NH3-SCR performance of CeO2/TiO2-SiO2-WO3 catalyst containing 10% CeO2. 展开更多
关键词 NH3-SCR NO cerium CeO2/TiO2-SiO2-WO3 monolith catalyst rare earths
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Effects of Atmospheres and Precursors on MnO_x/TiO_2 Catalysts for NH_3-SCR at Low Temperature 认领 引用 被引量:17
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作者 方德 HE Feng +2 位作者 谢峻林 FU Zhengbing CHEN Junfu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第5期888-892,共5页
The effects of atmospheres and precursors on MnOx/TiO2 catalysts were studied, which were prepared by the impregnation method and tested for their NOx conversion activity in ammonia selective catalytic reduction (NH3... The effects of atmospheres and precursors on MnOx/TiO2 catalysts were studied, which were prepared by the impregnation method and tested for their NOx conversion activity in ammonia selective catalytic reduction (NH3-SCR) reactions. Results showed that the manganese carbonate (MC) precursor caused mainly Mn2O3, while the manganese nitrate (MN) precursor resulted primarily in MnO2 and the manganese sulfate (MS) precursor was unchanged. The manganese acetate (MA) precursor leaded obtaining a mixture of Mn2O3 and Mn304. NOn conversion decreased in the following order: MA/TiO2 〉 MC/TiO2 〉 MN/TiO2 〉 MS/TiO2 〉 P25, with a calcination temperature of 773 K in air. Catalysts that were prepared by MA and calcined in oxygen performed strong interaction between Ti and Mn, while MnTiO3 was observed. Compared to the catalysts calcined in nitrogen, those calcined in oxygen had larger diameter and smaller surface area and pore. Catalysts that were prepared by MA and calcined in nitrogen tended to gain higher denitration rates than those in air, since they could be prepared with significant specific surface areas. NO., conversion decreased with calcination atmospheres: Nitrogen〉 Air〉 Oxygen. Meanwhile, amorphous Mn2O3 turned into crystalline Mn2O3, when the temperatures increased from 673 to 873 K. 展开更多
关键词 MnOx/TiO2 catalyst precursor atmosphere NH3-SCR
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Promoting effect and mechanism of neodymium on low-temperature selective catalytic reduction with NH3 over Mn/TiO2 catalysts 认领 引用 被引量:8
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作者 Peng Wu Yaping Zhang +3 位作者 Ke Zhuang Kai Shen Sheng Wang Tianjiao Huang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第11期1215-1223,I0003,共9页
Series of Mn/TiO2 catalysts modified with various contents of Nd for low-temperature SCR were synthesized.It can be found that the appropriate amount of Nd can markedly reduce the take-off temperature of Mn/TiO2 catal... Series of Mn/TiO2 catalysts modified with various contents of Nd for low-temperature SCR were synthesized.It can be found that the appropriate amount of Nd can markedly reduce the take-off temperature of Mn/TiO2 catalyst to 80℃and NOx conversion is stabilized over 90%in the wide temperature range of 100-2600 C.0.1 Nd-Mn/Ti shows higher N2 selectivity and better SO2 resistance than Mn/Ti catalyst.The results reveal that Nd-doped Mn/TiO2 catalyst exhibits larger BET surface area and better dispersion of active component Mn2O3.XPS results indicate that the optimal 0.1 Nd-Mn/Ti sample possesses higher concentration of Mn4+and larger amount of adsorbed oxygen at the surface compared with the unmodified counterpart.In situ DRIFTS show that the surface acidity is evidently increased after adding Nd,especially,the Lewis acid sites,and the intermediate(-NH2)is more stable.The reaction mechanism over Mn/Ti and 0.1 Nd-Mn/Ti catalysts obey the Eley-Rideal(E-R)mechanisms under low temperature reaction conditions.H2-TPR results show that Nd-Mn/TiO2 catalyst exhibits better lowtemperature redox properties. 展开更多
关键词 Nd modification Mn/TiO2 catalyst Low-temperature Selective catalyst reduction Mechanism Rare earths
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Selective catalytic oxidation of NO with O_2 over Ce-doped MnO_x/TiO_2 catalysts 认领 引用 被引量:29
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作者 Xiaohai Li Shule Zhang +2 位作者 Yong Jia Xiaoxiao Liu Qin Zhong 《Journal of Natural Gas Chemistry》 CSCD 2012年第1期17-24,共8页
A series of Ce-doped MnOx/TiO2 catalysts were prepared by impregnation method and used for catalytic oxidation of NO in the presence of excess O2. The sample with the Ce doping concentration of Ce/Mn=l/3 and calcined ... A series of Ce-doped MnOx/TiO2 catalysts were prepared by impregnation method and used for catalytic oxidation of NO in the presence of excess O2. The sample with the Ce doping concentration of Ce/Mn=l/3 and calcined at 300 ℃ shows a superior activity for NO oxidation to NO2. On Ce(1)Mn(3)Ti catalyst, 58% NO conversion was obtained at 200 ℃ and 85% NO conversion at 250 ℃ with a GHSV of 41000 h-1, which was much higher than that over MnOx/TiO2 catalyst (48% at 250 ℃). Characterization results implied that the higher activity of Ce(1)Mn(3)Ti could be attributed to the enrichment of well-dispersed MnO2 on the surface and the abundance of Mn3+ and Zi3+ species. The addition of Ce into MnO2/TiO2 could improve oxygen storage capacity and facilitate oxygen mobility of the catalyst as shown by PL and ESR, so that its activity for NO oxidation could be enhanced. The effect of H2O and SO2 on the catalyst activity was also investigated. 展开更多
关键词 selective catalytic oxidation (SCO) of NO MnOx/TiO2 catalysts Ce-doped catalysts
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The Effect of Titania Structure on Ni/TiO_2 Catalysts for p-Nitrophenol Hydrogenation 认领 引用 被引量:12
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作者 陈日志 杜艳 +1 位作者 邢卫红 徐南平 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2006年第5期665-669,共5页
The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over Ni/TiO2 catalysts prepared by a liquid-phase chemical reduction method. The catalysts were characterized by inductively coupled plasm... The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over Ni/TiO2 catalysts prepared by a liquid-phase chemical reduction method. The catalysts were characterized by inductively coupled plasma (ICP), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and temperature-programmed reduction (TPR). Results show that the titania structure has favorable influence on physio-chemical and catalytic properties of Ni/TiO2 catalysts. Compared to commercial Raney nickel, the catalytic activity of Ni/TiO2 catalyst is much superior, irrespective of the titania structure. The catalytic activity of anatase titania supported nickel catalyst Ni/TiO2(A) is higher than that of rutile titania supported nickel catalyst Ni/TiO2(R), possibly because the reduction of nickel oxide to metallic nickel for Ni/TiO2(A) is easier than that for Ni/TiO2(R) at similar reaction conditions. 展开更多
关键词 p-nitrophenol catalytic hydrogenation p-aminophenol Ni/TiO2 catalyst
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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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载体的制备条件对Mn-Ce/TiO_2催化剂脱硝活性的影响 认领 引用 被引量:5
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作者 吴彦霞 房晶瑞 +2 位作者 雷本喜 汪澜 考宏涛 《武汉理工大学学报》 CAS CSCD 北大核心 2013年第7期37-41,共5页
以TiO2粉末为原料,采用挤出成型、干燥、焙烧的方法制备条状TiO2载体,考察焙烧温度和焙烧时间对成型TiO2载体催化剂脱硝活性的影响。采用X射线衍射仪(XRD)、比表面积测定仪(BET)等手段对负载活性组分后的载体进行表征。结果表明,挤出成... 以TiO2粉末为原料,采用挤出成型、干燥、焙烧的方法制备条状TiO2载体,考察焙烧温度和焙烧时间对成型TiO2载体催化剂脱硝活性的影响。采用X射线衍射仪(XRD)、比表面积测定仪(BET)等手段对负载活性组分后的载体进行表征。结果表明,挤出成型的条状TiO2载体,在60℃下干燥12h、800℃下焙烧6h的条件下,以锐钛矿型TiO2晶型存在,有利于催化剂活性组分的负载,表现出最佳的脱硝性能。 展开更多
关键词 二氧化钛载体 Mn-Ce TiO2 脱硝 焙烧温度 焙烧时间
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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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Effect of TiO_2 surface properties on the SCR activity of NOx emission abatement catalyst 认领 引用 被引量:6
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作者 YEDai-qi TIANLiu-qing LIANGHong 《Journal of Environmental Sciences》 SCIE EI CAS 2002年第4期530-535,共6页
NOx emission abatement catalysts V 2O 5 supported on various TiO 2 including anatase, rutile and mixture of both were investigated with various physico\|chemical measurements such as BET, NH\-3\|TPD, NARP, XRD and so ... NOx emission abatement catalysts V 2O 5 supported on various TiO 2 including anatase, rutile and mixture of both were investigated with various physico\|chemical measurements such as BET, NH\-3\|TPD, NARP, XRD and so on, and the effect of TiO\-2 surface properties on the SCR(selective catalytic reduction) activity of V\-2O\-5/TiO\-2 catalysts was studied. It was found that the TiO\-2 surface properties had strong affect on the SCR activity of V\-2O\-5/TiO\-2 catalysts. The stronger acidic property resulted in the higher exposure of active sites as well as the higher SCR activity. 展开更多
关键词 NOx SCR(selective catalytic reduction) surface acidity V\-2O\-5/TiO\-2 catalyst
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SO2和H2O对Mn-Ce/TiO2催化剂低温SCR活性的影响 认领 引用 被引量:5
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作者 闫东杰 刘树军 +2 位作者 黄学敏 玉亚 徐颖 《安全与环境学报》 CAS CSCD 北大核心 2016年第5期308-312,共5页
采用溶胶凝胶法制备Mn-Ce/TiO2低温SCR催化剂并考察其活性,研究了SO2和H2O对Mn-Ce/TiO2低温脱硝催化剂的影响,并运用XRD、BET、SEM和FT-IR对中毒前后的催化剂进行表征。结果表明,催化剂在无SO2和H2O条件下具有良好的... 采用溶胶凝胶法制备Mn-Ce/TiO2低温SCR催化剂并考察其活性,研究了SO2和H2O对Mn-Ce/TiO2低温脱硝催化剂的影响,并运用XRD、BET、SEM和FT-IR对中毒前后的催化剂进行表征。结果表明,催化剂在无SO2和H2O条件下具有良好的脱硝性能,在140℃时NOx去除率达到84%。但若向模拟烟气中加入SO2和H2O,则随其体积分数增大对催化剂活性产生明显抑制作用。当H2O的体积分数为5%、SO2为700×10-6时,反应4 h后,NOx去除率降为53%。H2O对催化剂的抑制作用随H2O的除去而消除,H2O主要通过与NOx的竞争吸附来抑制催化剂的活性。低浓度的SO2对催化剂活性影响较小,SO2体积分数为100×10-6时,稳定后NOx去除率仍能维持在80%以上,但较高体积分数的SO2引起的催化剂失活不可自行恢复。SO2毒化作用主要是引起了硫酸铵盐覆盖催化剂的表面活性位,以及造成活性组分MnOx的晶化,并破坏了MnOx与TiO2间的强相互作用。H2O和SO2共同存在时,H2O可以弱化SO2对催化剂的毒化作用,主要因为H2O与SO2的竞争吸附作用而使SO2对催化剂活性的影响减弱。 展开更多
关键词 环境学 低温SCR Mn-Ce/TiO2催化剂 SO2 H2O
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低温选择性催化还原脱硝Mn-Ce/TiO2催化剂的Pb中毒与再生研究 认领 引用 被引量:11
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作者 闫东杰 郭通 +1 位作者 玉亚 陈兆辉 《燃料化学学报》 CSCD 北大核心 2021年第1期113-120,共8页
考察了Pb对Mn-Ce/TiO2低温选择性催化还原(SCR)脱硝活性的影响,并对Pb中毒的催化剂进行了再生;结合氮吸附、SEM、XRD、FT-IR、H2-TPR和NH3-TPD等表征结果,研究了Mn-Ce/TiO2催化剂Pb中毒和再生活性恢复的原因。结果表明,Pb对Mn-Ce/TiO2... 考察了Pb对Mn-Ce/TiO2低温选择性催化还原(SCR)脱硝活性的影响,并对Pb中毒的催化剂进行了再生;结合氮吸附、SEM、XRD、FT-IR、H2-TPR和NH3-TPD等表征结果,研究了Mn-Ce/TiO2催化剂Pb中毒和再生活性恢复的原因。结果表明,Pb对Mn-Ce/TiO2催化剂脱硝活性有明显的抑制作用;当Pb的含量为11%时,Mn-Ce/TiO2催化剂在180℃下的脱硝效率从原来100%下降至44%。Pb在Mn-Ce/TiO2中的掺杂使得催化剂的比表面积以及活性组分Mn^4+和Ce^3+的含量降低,影响了氧化还原循环反应(Mn^4++Ce^3+↔Mn^3++Ce^4+)的进行;此外,Pb的加入破坏了催化剂的酸性位点,阻碍了催化剂对NH3的吸附和活化。经硝酸再生后的Mn-Ce/TiO2催化剂的脱硝活性几乎完全恢复,在80-150℃下其脱硝活性甚至超过新鲜未中毒的催化剂,其原因主要在于硝酸再生能恢复催化剂的氧化还原能力、增大比表面积、并形成新的酸位点。 展开更多
关键词 低温选择性催化还原脱硝 Mn-Ce/TiO2 Pb中毒 再生
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