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Effect of samarium doping on the activity and sulfur resistance of Ce/MnFeO_(x) catalyst for low-temperature selective catalytic reduction of NO_(x) by ammonia
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作者 Qiyao Zhang Shuangshuang Zhang +1 位作者 Xu Hu Yongmin Huang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期272-282,共11页
The self-made MnFeO_(x) catalysts doped with cerium and samarium were prepared by impregnation method for low-temperature selective catalytic reduction(SCR)by NH3.In this work,the surface properties of the series of M... The self-made MnFeO_(x) catalysts doped with cerium and samarium were prepared by impregnation method for low-temperature selective catalytic reduction(SCR)by NH3.In this work,the surface properties of the series of MnFe-based catalysts were studied.The results indicate Sm-modified catalyst have superior low-temperature SCR activity;NO_(x) conversion maintained at nearby to 100%at 90℃ to 240℃.In addition,The N_(2) selectivity of Sm doping remains above 80%in the range of 60℃ to 150℃.In SO_(2) poisoning test,the NO_(x) conversion can be remained>90%after 10 h of reaction.The XPS,NH_(3)-TPD and H_(2)-TPR results show the catalyst with Sm doping enhances the acid sites and oxidation catalytic sites of mixed oxides serves for improving oxygen vacancies and transfer electrons.In situ diffuse reflaxions infrared Fourier transformations spectroscopy(DRIFTS)results show that NO_(x) is more easily adsorbed on the surface after Sm doping,which provided favorable conditions for the NH_(3)-SCR reaction to proceed.The reaction at the catalyst surface will follow the L-H reaction mechanism by transient reaction test. 展开更多
关键词 scr Sm doping catalyst Sulfur resistance In situ DRIFTS SELECTIVITY
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Molecular engineering binuclear copper catalysts for selective CO_(2) reduction to C_(2) products
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作者 Qi Zhao Kai Lei +2 位作者 Bao Yu Xia Rachel Crespo-Otero Devis Di Tommaso 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期166-173,I0005,共9页
Molecular copper catalysts serve as exemplary models for correlating the structure-reaction-mechanism relationship in the electrochemical CO_(2) reduction(eCO_(2)R),owing to their adaptable environments surrounding th... Molecular copper catalysts serve as exemplary models for correlating the structure-reaction-mechanism relationship in the electrochemical CO_(2) reduction(eCO_(2)R),owing to their adaptable environments surrounding the copper metal centres.This investigation,employing density functional theory calculations,focuses on a novel family of binuclear Cu molecular catalysts.The modulation of their coordination configuration through the introduction of organic groups aims to assess their efficacy in converting CO_(2) to C_(2)products.Our findings highlight the crucial role of chemical valence state in shaping the characteristics of binuclear Cu catalysts,consequently influencing the eCO_(2)R behaviour,Notably,the Cu(Ⅱ)Cu(Ⅱ)macrocycle catalyst exhibits enhanced suppression of the hydrogen evolution reaction(HER),facilitating proton trans fer and the eCO_(2)R process.Fu rthermore,we explo re the impact of diverse electro n-withdrawing and electron-donating groups coordinated to the macrocycle(R=-F,-H,and-OCH_3)on the electron distribution in the molecular catalysts.Strategic placement of-OCH_3 groups in the macrocycles leads to a favourable oxidation state of the Cu centres and subsequent C-C coupling to form C_(2) products.This research provides fundamental insights into the design and optimization of binuclear Cu molecular catalysts for the electrochemical conversion of CO_(2) to value-added C_(2) products. 展开更多
关键词 Molecular catalyst design selective CO_(2)reduction C_(2)products Density functional theory calculations
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A Comparison of Hydrothermal Aging, SO2 and Propene Poisoning Effects on NH3-SCR over Cu-ZSM-5 and Cu-SAPO-34 Catalysts
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作者 Kouadio Brou Albert Koffi Konan Martin +1 位作者 Zran Van Eric-Simon Horo Kone 《Journal of Materials Science and Chemical Engineering》 2024年第5期10-28,共19页
This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both... This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) of NO<sub>x</sub> conditions. The XRD, TG and N<sub>2</sub>-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO<sub>2</sub> and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO<sub>2</sub> or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO<sub>2</sub> or propene compared to Cu-SAPO-34 catalyst. The H<sub>2</sub>-TPR results showed that Cu<sup>2 </sup> ions could be reduced to Cu<sup> </sup> and Cu<sup>0</sup> for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore. 展开更多
关键词 Hydrothermal Aging Propene and SO2Poisoning Ammonia-selective Catalytic reduction(NH3-scr) Cu-SAPO-34 CU-ZSM-5
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Influence of coke rate on thermal treatment of waste selective catalytic reduction(SCR)catalyst during iron ore sintering
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作者 Pengnan Ma Jiankang Wang +4 位作者 Hanxiao Meng Laiquan Lv Hao Fang Kefa Cen Hao Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第2期415-423,共9页
Waste selective catalytic reduction(SCR)catalyst as a hazardous waste has a significant impact on the environment and human health.In present study,a novel technology for thermal treatment of waste SCR catalyst was pr... Waste selective catalytic reduction(SCR)catalyst as a hazardous waste has a significant impact on the environment and human health.In present study,a novel technology for thermal treatment of waste SCR catalyst was proposed by adding it to sinter mix for iron ore sintering.The influences of coke rate on the flame front propagation,sinter microstructure,and sinter quality during sintering co-processing the waste SCR catalyst process were studied.In situ tests results indicated the maximum sintering bed temperature increased at higher coke rate,indicating more liquid phase generated and higher airflow resistance.The sintering time was longer and the calculated flame front speed dropped at higher coke rate.Sinter microstructure results found the coalescence and reshaping of bubbles were more fully with increasing coke rate.The porosity dropped from 35.28%to 25.66%,the pore average diameter of large pores decreased from 383.76μm to 311.43μm.With increasing coke rate,the sinter indexes of tumbler index,productivity,and yield,increased from 33.2%,9.2 t·m^(-2)·d^(-1),28.9%to 58.0%,36.0 t·m^(-2)·d^(-1),68.9%,respectively.Finally,a comprehensive index was introduced to systematically assess the influence of coke rate on sinter quality,which rose from 100 to 200 when coke rate was increased from 3.5%(mass)to 5.5%(mass). 展开更多
关键词 Flame front Waste selective catalytic reduction(scr) catalyst Thermal treatment Iron ore sintering
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Fe-Mn/Al_2O_3 catalysts for low temperature selective catalytic reduction of NO with NH_3 被引量:6
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作者 王晓波 伍士国 +3 位作者 邹伟欣 虞硕涵 归柯庭 董林 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1314-1323,共10页
A series of Fe‐Mn/Al2O3 catalysts were prepared and studied for low temperature selective catalytic reduction (SCR) of NO with NH3 in a fixed‐bed reactor. The effects of Fe and Mn on NO conversion and the deactiva... A series of Fe‐Mn/Al2O3 catalysts were prepared and studied for low temperature selective catalytic reduction (SCR) of NO with NH3 in a fixed‐bed reactor. The effects of Fe and Mn on NO conversion and the deactivation of the catalysts were studied. N2 adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, H2 temperature‐programmed reduction, NH3 temperature‐programmed desorption, X‐ray photoelectron spectroscopy (XPS), thermal gravimetric analysis and Fourier transform infrared spectroscopy were used to character‐ize the catalysts. The 8Fe‐8Mn/Al2O3 catalyst gave 99%of NO conversion at 150?? and more than 92.6%NO conversion was obtained in a wide low temperature range of 90–210??. XPS analysis demonstrated that the Fe3+was the main iron valence state on the catalyst surface and the addition of Mn increased the accumulation of Fe on the surface. The higher specific surface area, enhanced dispersion of amorphous Fe and Mn, improved reduction properties and surface acidity, lower binding energy, higher Mn4+/Mn3+ratio and more adsorbed oxygen species resulted in higher NO conversion for the 8Fe‐8Mn/Al2O3 catalyst. In addition, the SCR activity of the 8Fe‐8Mn/Al2O3 cata‐lyst was only slightly decreased in the presence of H2O and SO2, which indicated that the catalyst had better tolerance to H2O and SO2. The reaction temperature was crucial for the SO2 resistance of catalyst and the decrease of catalytic activity caused by SO2 was mainly due to the sulfate salts formed on the catalyst. 展开更多
关键词 Nitrogen monoxide Low-temperature selective catalytic reduction Fe-Mn catalyst X-ray photoelectron spectroscopy Sulfur dioxide Fourier transform infrared spectroscopy
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Resistance to SO_2 poisoning of V_2O_5/TiO_2-PILC catalyst for the selective catalytic reduction of NO by NH_3 被引量:4
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作者 臧思淼 张桂臻 +3 位作者 邱文革 宋丽云 张然 何洪 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第6期888-897,共10页
A titania pillared interlayered clay(Ti-PILC) supported vanadia catalyst(V2O5/TiO2-PILC) was prepared by wet impregnation for the selective catalytic reduction(SCR) of NO with ammonia. Compared to the traditiona... A titania pillared interlayered clay(Ti-PILC) supported vanadia catalyst(V2O5/TiO2-PILC) was prepared by wet impregnation for the selective catalytic reduction(SCR) of NO with ammonia. Compared to the traditional V2O5/TiO2 and V2O5-MoO3/TiO2 catalysts, the V2O5/TiO2-PILC catalyst exhibited a higher activity and better SO2 and H2O resistance in the NH3-SCR reaction. Characterization using TPD, in situ DRIFT and XPS showed that surface sulfate and/or sulfite species and ionic SO4^(2-)species were formed on the catalyst in the presence of SO2. The ionic SO4^(2-) species on the catalyst surface was one reason for deactivation of the catalyst in SCR. The formation of the ionic SO4^(2-) species was correlated with the amount of surface adsorbed oxygen species. Less adsorbed oxygen species gave less ionic SO4^(2-) species on the catalyst. 展开更多
关键词 selective catalytic reduction TiO2-pillared clay Nitrogen oxide Vanadia catalyst In situ diffuse reflectance infrared Fourier transform spectroscopy
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One-pot synthesis of bimetallic CeCu-SAPO-34 for high-efficiency selective catalytic reduction of nitrogen oxides with NH_(3) at low temperature 被引量:1
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作者 Shuang Qiu Yonghou Xiao +3 位作者 Haoran Wu Shengnan Lu Qidong Zhao Gaohong He 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第4期193-202,共10页
NH_(3) selective catalytic reduction(SCR) has been widely recognized as a promising technique for reducing nitrogen oxides from diesel vehicle exhausts. High-efficiency SCR catalysts that could perform at low temperat... NH_(3) selective catalytic reduction(SCR) has been widely recognized as a promising technique for reducing nitrogen oxides from diesel vehicle exhausts. High-efficiency SCR catalysts that could perform at low temperatures are essential to denitration. In this work, a series of bimetallic CeCu-SAPO-34 molecular sieves were synthesized by one-step hydrothermal method. The Ce Cu-SAPO-34 maintained good crystallinity and a regular hexahedron appearance of Cu-SAPO-34 after introducing Ce species, while exhibiting a higher specific surface area and pore volume. The as-prepared CeCu-SAPO-34 with 0.02%(mass) Ce constituent exhibited the best catalytic activity below 300℃ and a maximum NO_(x) conversion of 99% was attained;the NO_(x) removal rates of more than 68% and 94% were achieved at 150℃ and 200℃, respectively. And the introduction of cerium species in Cu-SAPO-34 improves the low-temperature hydrothermal stability of the catalyst towards NH_(3)-SCR reaction. Additionally, the introduced Ce species could enhance the formation of abundant weak Br?nsted acid centers and promote the synergistic effect between CuO grains and isolated Cu^(2+) to enhance the redox cycle, which benefit the NH_(3)-SCR reaction.This work provides a facile synthesis method of high-efficiency SCR denitration catalysts towards diesel vehicles exhaust treatment under low temperature. 展开更多
关键词 CeCu-SAPO-34 selective catalytic reduction(scr) Low temperature DeNO_(x) One-pot synthesis
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Kinetics of selective catalytic reduction of NO by NH_3 on Fe-Mo/ZSM-5 catalyst 被引量:9
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作者 LI Zhe SHEN Lin-tao HUANG Wei XIE Ke-chang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第12期1516-1519,共4页
The catalyst of Fe-Mo/ZSM-5 has been found to be more active than Fe-ZSM-5 and Mo/ZSM-5 separately for selective catalytic reduction (SCR) of nitric oxide (NO) with NH3. The kinetics of the SCR reaction in the pre... The catalyst of Fe-Mo/ZSM-5 has been found to be more active than Fe-ZSM-5 and Mo/ZSM-5 separately for selective catalytic reduction (SCR) of nitric oxide (NO) with NH3. The kinetics of the SCR reaction in the presence of O2 was studied in this work. The results showed that the observed reaction orders were 0.74-0.99, 0.01-0.13, and 0 for NO, O2 and NH3 at 350-450℃, respectively. And the apparent activation energy of the SCR was 65 kJ/mol on the Fe-Mo/ZSM-5 catalyst. The SCR mechanism was also deduced. Adsorbed NO species can react directly with adsorbed ammonia species on the active sites to form N2 and H2O. Gaseous O2 might serve as a reoxidizing agent for the active sites that have undergone reduction in the SCR process. It is also important to note that a certain amount of NO was decomposed directly over the Fe-Mo/ZSM-5 catalyst in the absence of NH3. 展开更多
关键词 selective catalytic reduction scr nitric oxide (NO) Fe-Mo/ZSM-5 KINETICS activation energy
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Influence of chromium modification on the properties of MnO_x-FeO_x catalysts for the low-temperature selective catalytic reduction of NO by NH_3 被引量:7
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作者 Kai Shen Yaping Zhang +3 位作者 Xiaolei Wang Haitao Xu Keqin Sun Changcheng Zhou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第4期617-623,共7页
Catalytic properties of MnOx-FeOx complex oxide (hereafter denoted as Mn-Fe) catalysts modified with different loadings of chromium oxide were investigated by using the combination of physico-cbemical techniques, su... Catalytic properties of MnOx-FeOx complex oxide (hereafter denoted as Mn-Fe) catalysts modified with different loadings of chromium oxide were investigated by using the combination of physico-cbemical techniques, such as N2 physisorption, X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), in situ Fourier transform infrared spectroscopy (in situ FT-IR) and temperature-programmed reduction (TPR) and their catalytic activities were evaluated with the selective catalytic reduction (SCR) of NOx by NH3. It was found that with the addition of Cr, more NO could be removed in the low-temperature window (below 120 ℃). Among the tested catalysts, Mn-Fe- Cr (2 : 2 : 1) catalyst exhibited the best catalytic performance at 80 ℃ with the NO conversion higher than 90%. The combination of the reaction and characterization results indicated that (1) the strong interaction among tertiary metal oxides existed in the catalysts when Cr was appropriately added, which made the active components better dispersed with less agglomeration and sintering and the largest BET specific surface area could be obtained; (2) Cr improved the low-temperature reducibility of the catalyst and promoted the formation of the active intermediate (-NH3+), which favored the low-temperature SCR reaction. 展开更多
关键词 MnOx-FeOx Cr MODIFICATION low-temperature selective catalytic reduction catalystS
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Cu改性MIL-100(Fe)催化剂的SCR-C_(3)H_(6)脱硝特性
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作者 付维 宁淑英 +3 位作者 蔡晨 陈佳音 周皞 苏亚欣 《化工进展》 EI CAS CSCD 北大核心 2024年第9期4951-4960,共10页
烃类化合物选择性催化还原氮氧化物(SCR-HC)是一种很有发展前景的脱硝技术。催化剂有效的氧化-还原能力是影响其活性的关键因素。利用水热法制备了新型有机金属骨架MIL-100(Fe),通过超声浸渍法合成不同Cu含量的m Cu-MIL-100(Fe)催化剂,... 烃类化合物选择性催化还原氮氧化物(SCR-HC)是一种很有发展前景的脱硝技术。催化剂有效的氧化-还原能力是影响其活性的关键因素。利用水热法制备了新型有机金属骨架MIL-100(Fe),通过超声浸渍法合成不同Cu含量的m Cu-MIL-100(Fe)催化剂,在固定床微反应器中对其催化C_(3)H_(6)选择性还原NO的特性进行了实验研究。结果表明Cu的引入使MIL-100(Fe)催化活性得到改善。2.3Cu-MIL-100(Fe)的NO转化率在275℃下可达到100%,275~400℃范围内可维持85%以上NO转化率及90%以上N_(2)选择性,且具有较好抗SO_(2)的能力。通过各种技术手段对催化剂的微观结构及物化性质进行了表征,并对反应机理作了进一步讨论。N_(2)吸附-脱附结果表明,加入适量Cu可以增大催化剂的比表面积,并增强催化剂表面对反应气体的吸附能力;XPS研究结果表明,Cu可以提高催化剂表面的氧空位数目。Cu与Fe之间具有协同作用,二者之间存在电子转移现象。H_(2)-TPR曲线表明Cu使催化剂的还原特征峰向低温方向移动,增强了其还原性能。 展开更多
关键词 氮氧化物 选择催化还原 碳氢化合物 催化剂 Cu改性 抗SO_(2)性能
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TiO_2-Supported Binary Metal Oxide Catalysts for Low-temperature Selective Catalytic Reduction of NO_x with NH_3 被引量:5
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作者 WU Bi-jun LIU Xiao-qin +1 位作者 XIAO Ping WANG Shu-gang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第5期615-619,共5页
Binary metal oxide(MnOx-A/TiO2)catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide(TiO2),where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 sele... Binary metal oxide(MnOx-A/TiO2)catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide(TiO2),where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order:Mn-W/TiO2〉Mn-Fe/TiO2〉Mn-Cr/TiO2〉Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order:Mn-Fe/TiO2〉Mn-W/TiO2〉Mn-Mo/TiO2〉Mn-Cr/TiO2.In the presence of 0.01%SO2 and 6%H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8%and 94.2%, respectively,after 8 h at 120°C at GHSV 12600 h? 1 .As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared(FTIR)spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3. 展开更多
关键词 selective catalytic reduction of NO with NH3 Low-temperature selective catalytic reduction Binary metal oxide catalyst FTIR NH3-TPD
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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 被引量:9
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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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Experimental and Kinetic Study of Selective Catalytic Reduction of NO with NH_3 over CuO/Al_2O_3/Cordierite Catalyst 被引量:6
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作者 雷志刚 龙爱斌 +1 位作者 贾美如 刘学义 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第5期721-729,共9页
The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The... The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy Eá of 94.01 kJ·mol-1 and the corresponding p re-exponential factor A′ of 3.39×108 cm3·g-1·s-1 when NH3 is excessive. However, when NH3 is not enough, an E ley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ·mol-1, the corresponding A of 2 .94×109 cm3·g-1·s-1, heat of adsorption-Hads of 87.90 kJ·mol-1 and the corresponding Aads of 9.24 cm3·mol-1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reac-tor design and engineering scale-up. 展开更多
关键词 kinetics selective catalytic reduction CuO/γ-Al2O3/cordierite catalyst monolithic honeycomb reactor mathematical model
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The role of morphology on the electrochemical CO_(2) reduction performance of transition metal-based catalysts
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作者 Umar Mustapha Chidera C.Nnadiekwe +7 位作者 Maria Abdulkarim Alhaboudal Umar Yunusa Abdulhakam Shafiu Abdullahi Ismail Abdulazeez Ijaz Hussain Saheed A.Ganiyu Abdulaziz A.Al-Saadi Khalid Alhooshani 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第10期198-219,I0007,共23页
The continued increase in population and the industrial revolution have led to an increase in atmospheric carbon dioxide(CO_(2)) concentration. Consequently, developing and implementing effective solutions to reduce C... The continued increase in population and the industrial revolution have led to an increase in atmospheric carbon dioxide(CO_(2)) concentration. Consequently, developing and implementing effective solutions to reduce CO_(2) emissions is a global priority. The electrochemical CO_(2) reduction reaction(CO_(2)RR) is strongly believed to be a promising alternative to fossil fuel-based technologies for the production of value-added chemicals. So far, the implementation of CO_(2)RR is hindered by associated electrochemical reactions, such as low selectivity, hydrogen evolution reaction(HER), and additional overpotential induced in some cases. As a result, it is necessary to conduct a timely evaluation of the state-of-the-art strategies in CO_(2)RR, with a focus on the engineering of the electrocatalytic systems. Catalyst morphology is one factor that plays a critical role in overcoming these drawbacks and significantly contributes to enhancing product selectivity and Faradaic efficiency(FE). This review article summarizes the recent advances in the rational design of electrocatalysts with various morphologies and the influence of these morphologies on CO_(2)RR. To compare literature findings in a meaningful way, the article focuses on results reported under a well-defined period and considers the first three rows of the d-block metal catalysts. The discussion typically covers the design of nanostructured catalysts and the molecular-level understanding of morphology-performance relationship in terms of activity, selectivity, and stability during CO_(2) electrolysis. Among others, it would be convenient to recommend a comprehensive discussion on the morphologies of single metals and heterostructures, with a detailed emphasis on their impact on CO_(2) conversion. 展开更多
关键词 CO_(2)electroreduction Electrochemical reduction of CO_(2) MORPHOLOGY catalystS d-block metals catalysts Faradaic efficiency Selectivity
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Building up a general selection strategy and catalytic performance prediction expressions of heteronuclear double-atom catalysts for N_(2)reduction
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作者 Yibo Wu Cheng He Wenxue Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第7期375-386,I0009,共13页
The severe environmental problems and the demand for energy urgently require electrocatalysis to replace Haber-Bosch for the nitrogen reduction reaction(NRR).The descriptors and important properties of single-atom and... The severe environmental problems and the demand for energy urgently require electrocatalysis to replace Haber-Bosch for the nitrogen reduction reaction(NRR).The descriptors and important properties of single-atom and homonuclear double-atom catalysts have been preliminarily explored,but the relationship between the inherent properties and catalytic activity of heteronuclear double-atom catalysts with better performance remains unclear.Therefore,it is very significant to explore the prediction expressions of catalytic activity of heteronuclear double-atom catalysts based on their inherent properties and find the rule for selecting catalytic centers.Herein,by summarizing the free energy for the key steps of NRR on 55 catalysts calculated through the first-principle,the expressions of predicting the free energy and the corresponding descriptors are deduced by the machine learning,and the strategy for selecting the appropriate catalytic center is proposed.The selection strategy for the central atom of heteronuclear double-atom catalysts is that the atomic number of central B atom should be between group VB and VIIIB,and the electron difference between central A atom and B atom should be large enough,and the selectivity of NRR or hydrogen evolution reaction(HER)could be calculated through the prediction formula.Moreover,five catalysts are screened to have low limiting potential and excellent selectivity,and are further analyzed by electron transfer.This work explores the relationship between the inherent properties of heteronuclear double-atom catalysts and the catalytic activity,and puts forward the rules for selecting the heteronuclear double-atom catalytic center,which has guiding significance for the experiment. 展开更多
关键词 Heteronuclear double-atom catalyst Nitrogen reduction reaction Density functional theory Prediction expression Selection strategy
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Transfer and Reaction Performances of Selective Catalytic Reduction of NzO with CO over Monolith Catalysts 被引量:3
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作者 代成娜 雷志刚 +2 位作者 王玉丽 张润铎 陈标华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期835-843,共9页
This work tries to identify the relationship between geometric configuration of monolith catalysts, and transfer and reaction performances for selective catalytic reduction of N2O with CO. Monolith catalysts with five... This work tries to identify the relationship between geometric configuration of monolith catalysts, and transfer and reaction performances for selective catalytic reduction of N2O with CO. Monolith catalysts with five different channel shapes (circle, regular triangle, rectangle, square and hexagon), was investigated to make a comprehensive comparison of their pressure drop, heat transfer Nu number, mass transfer Sh number and N2O conversion. It was found that monolith catalysts have a much lower pressure drop than that of traditional packed bed, and for monolith catalysts with different channel shapes, pressure drop decreases in the order of regular triangle > rectangle > square > hexagon > circle. The order of Nu is in regular triangle > rectangle ≈ square > hexagon > circle, similar to that of Sh. N2O conversion follows the order of regular triangle > rectangular ≈ square ≈ circle > hexagon. The results indicate that chemical reaction including internal diffusion is the controlling step in the selective catalytic reduction of N2O removal with CO. In addition, channel size and gas velocity also have influence on N2O conversion and pressure drop. 展开更多
关键词 selective catalytic reduction N2O conversion momentum transfer heat transfer mass transfer monolith catalysts mathematical modeling
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Research progress in the SO2 resistance of the catalysts for selective catalytic reduction of NOx 被引量:9
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作者 Minhua Zhang Baojuan Huang +1 位作者 Haoxi Jiang Yifei Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第12期1695-1705,共11页
The selective catalytic reduction (SCR) of NOx with NH3 has been proven to be an efficient technology for NOx conversion to N2. However, the catalysts used for SCR usually suffer from the problem of sulfur poisoning... The selective catalytic reduction (SCR) of NOx with NH3 has been proven to be an efficient technology for NOx conversion to N2. However, the catalysts used for SCR usually suffer from the problem of sulfur poisoning which seriously limits their practical application. This review summarized sulfur poisoning mechanisms of various SCR deNG catalysts and strategies to reduce deactivation caused by SO2 such as doping metals, controlling the structures and morphologies of the catalysts, and selecting appropriate supports. The methods and procedures of catalysts preparation and the reaction conditions also have effect on SO2-resistance of the catalysts. Several novel catalyst systems that exhibited good SO2 resistance are also introduced. This paper could provide guidance for the development of highly efficient sulfur-tolerant deNOx catalysts. 展开更多
关键词 Words selective catalytic reduction scr)SO2 resistance catalyst NOx
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Selective catalytic reduction of NO with NH_3 over sol-gel-derived CuO-CeO_2-MnO_x/γ-Al_2O_3 catalysts 被引量:2
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作者 赵清森 向军 +3 位作者 孙路石 石金明 苏胜 胡松 《Journal of Central South University》 SCIE EI CAS 2009年第3期513-519,共7页
Granular CuO-CeO2-MnOx/γ-Al2O3 catalysts were synthesized by the sol-gel method. The performance of the CuO-CeO2-MnOx/γ-Al2O3 catalysts for the selective catalytic reduction (SCR) was studied in a fixed bed system. ... Granular CuO-CeO2-MnOx/γ-Al2O3 catalysts were synthesized by the sol-gel method. The performance of the CuO-CeO2-MnOx/γ-Al2O3 catalysts for the selective catalytic reduction (SCR) was studied in a fixed bed system. Preliminary tests were carried out to analyze the behavior of NH3 and NO over catalyst in the presence of oxygen. The optimum temperature range for SCR over the CuO-CeO2-MnOx/γ-Al2O3 catalysts is 300-400 ℃ . The catalysts maintain nearly 100% NO conversion at 350 ℃. The NH3 oxidation experiments show that both NO and N2O are produced gradually with the increase of temperature. The catalysts in this experiment have a stronger oxidation property on NH3, which improves the denitrification activity at low temperature. The over-oxidation of NH3 at high temperature is the main cause leading to a decrease in the NO conversion. The NH3 and NO desorption experiments show that NH3 and NO can be adsorbed on CuO-CeO2-MnOx/γ-Al2O3 granular catalysts. The transient response of NH3 and NO indicates that the SCR reaction proceeds in accordance with the Eley-Rideal mechanism. The adsorbed NO has little influence on the denitrification activity in SCR process. 展开更多
关键词 sol-gel method CuO-CeO2-MnOx/γ-Al2O3 NH3 NO CONVERSION selective catalytic reduction scr
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废弃SCR催化剂中砷的二次释放行为研究
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作者 李鹏 康瑾 +3 位作者 骆宏飞 王昆 王泽安 刘豪 《环境科学与技术》 CAS CSCD 北大核心 2024年第4期125-132,共8页
为了降低废弃SCR催化剂中砷的二次释放对环境的危害,文章应用XRD、XRF、SEM-EDS、ICP-OES等分析手段,采取柱浸出实验方法模拟自然降雨或水蚀条件下废弃SCR催化剂中砷的释放行为及特性,设计了砷的热释放在线监测系统,探索废弃SCR催化剂... 为了降低废弃SCR催化剂中砷的二次释放对环境的危害,文章应用XRD、XRF、SEM-EDS、ICP-OES等分析手段,采取柱浸出实验方法模拟自然降雨或水蚀条件下废弃SCR催化剂中砷的释放行为及特性,设计了砷的热释放在线监测系统,探索废弃SCR催化剂中砷在受热条件下的二次释放行为。结果表明:(1)废弃SCR催化剂中砷含量高达1.477%;(2)废弃SCR催化剂中砷在酸性水浴条件下(pH=5)析出率可达39.71%,析出率与水浴pH值呈负相关;(3)在受热条件下,废弃SCR催化剂中砷在800~1 000℃温度段可100%释放。因此,废弃SCR催化剂在储存及运输过程中应避免雨水冲刷,采用低温回收方法,可降低废弃或中毒SCR催化剂中砷的二次危害。 展开更多
关键词 选择性催化还原 脱硝催化剂 二次释放 淋滤
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基于7状态船舶柴油机SCR脱硝系统的精细化建模与控制
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作者 魏京蕾 许媛媛 +1 位作者 彭黎 陶邦林 《船舶工程》 CSCD 北大核心 2024年第4期29-35,共7页
传统的3状态选择性催化还原(SCR)脱硝模型只关注NO和NH3对系统的影响,忽略了NO2的作用,但研究发现,NO2的影响也不可忽视。为此,考虑NO和NO2对SCR脱硝系统的影响,设计面向双催化剂、包含NO2的7状态船舶SCR脱硝系统机理模型,分析NO2对船... 传统的3状态选择性催化还原(SCR)脱硝模型只关注NO和NH3对系统的影响,忽略了NO2的作用,但研究发现,NO2的影响也不可忽视。为此,考虑NO和NO2对SCR脱硝系统的影响,设计面向双催化剂、包含NO2的7状态船舶SCR脱硝系统机理模型,分析NO2对船舶脱硝系统性能的影响,讨论精细化模型的精度。此外,从节能降耗角度出发,设计模型预测控制器,对比不同模型的控制效果,结果表明,相比于传统的3状态模型,基于7状态的精细化模型具有更优的控制效果。 展开更多
关键词 选择性催化还原 脱硝率 氨逃逸 模型预测控制
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