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Journal of Environmental Sciences 2012年第7期24卷 1305-1316页

作者： ziran ma Duan Weng Xiaodong Wu Zhichun Si State Key Laboratory of New Ceramics&Fine Process Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Yangtze Delta Region Institute of Tsinghua University Zhejiang 314000China Advanced materials Institute Graduate School at ShenzhenTsinghua UniversityShenzhen 518055China

A series of WO3/CeO2 （WOx/CeO2） catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO2 support. The resulting solid acid catalysts were characterized by X-ray diffraction （XRD）, UV-Vis spectroscopy （UV-Vis）, Raman spectroscopy （Raman）, in-situ Fourier transform infrared spectroscopy （in-situ FT-IR） of ammonia adsorption, NH3-TPD, H2 temperature- programmed reduction （H2-TPR）, NH3/NO oxidation and activity measurements for NOx reduction by NH3 （NH3-SCR）. The results show that polytungstate （WOx） species are the main species of tungsten oxide on the surface of ceria. The addition of tungsten oxide enhances the BriSnsted acidity of ceria catalysts remarkably and decreases the amount of surface oxygen on celia, with strong interaction between CeO2 and WOx. As a result, the N2 selectivity of NH3 oxidation and NH3-SCR at high temperatures （〉 300℃） is enhanced. Therefore, a wide working temperature window in which NOx conversion exceeds 80% （NOx conversion 〉 80%） from 200 to 450℃, is achieved over 10 wt.% WOx/CeO2 catalyst. A tentative model of the NH3-SCR reaction route on WOx/CeO2 catalysts is presented.

关键词： NOx reduction WOx/CeO2 catalyst redox NH3 adsorption

Effects of MOx(M=Mn,Cu,Sb,La)on V-Mo-Ce/Ti selective catalytic reduction catalysts

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Journal of Rare Earths 2020年第2期38卷 157-166页

作者： Daojun Zhang ziran ma Baodong Wang Qi Sun Wenqiang Xu Tao Zhu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China National Institute of Clean-and-Low-Carbon Energy Beijing 102211China School of Chemical&Environmental Engineering China University of Mining&Technology(Beijing)Beijing 100083China

A series of MOx-V2O5-MoO3-CeO2/TiO2(M=Mn,Cu,Sb,and La) catalysts were prepared via an impregnation *** physico-chemical properties of the catalysts were characterized and their NH3-SCR of NO performance was *** Mn-loaded catalyst(Mn5V1Mo3Ce7/Ti) exhibits a large number of acid sites of varying strength,and together with good reducibility of the catalyst,contributes to the optimal SCR *** sulphate species formed in the presence of SO2 significantly enhance the H2O and SO2 tolerance of Mn5V1Mo3Ce7/*** Cu-loaded catalyst(Cu5V1Mo3Ce7/Ti)demonstrates potential in flue gas applications in the absence of SO2 at low temperatures because of the excellent redox ability observed and the high degree of weak acid *** Sb and La loaded catalysts(Sb5V1Mo3Ce7/Ti and La5V1Mo3Ce7/Ti),especially La5V1Mo3 Ce7/Ti,exhibit the largest number of acid sites and the lowest reducibility,and therefore,may be suitable for use in high temperature denitrification applications.

关键词： Selective catalytic reduction Vanadium manganese Copper Antimony Rare earths

Low-temperature SCR activity and SO2 deactivation mechanism of Ce-modified V2O5–WO3/TiO2 catalyst

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Progress in Natural Science:materials International 2015年第4期25卷 342-352页

作者： ziran ma Xiaodong Wu Ya Feng Zhichun Si Duan Weng Lei Shi The Key Laboratory of Advanced materials of Ministry of Education School of Materials Science and EngineeringTsinghua University National Institute of Clean-and-Low-Carbon Energy(NICE) Advanced materials Institute Graduate School at ShenzhenTsinghua University Redbud Innovation Institute

The promotion effect of ceria modi fi cation on the low-temperature activity of V2O5-WO3/TiO2 catalyst was evaluated for the selective catalytic reduction of NO with NH3(NH3-SCR). The catalytic activity of 1 wt% V2O5-WO3/TiO2 was signi fi cantly enhanced by the addition of 8 wt%ceria, which exhibited a NO x conversion above 80% in a broad temperature range 190–450 1C. This performance was comparable with 3 wt%V2O5-WO3/TiO2, indicating that the addition of ceria contributed to reducing the usage of toxic vanadia in developing low-temperature SCR catalysts. Moreover, V1 Ce WTi exhibited approximately 10% decrease in NOx conversion in the presence of 60 ppm SO2. The characterization results indicated that active components of V, W and Ce were well dispersed on TiO2 support. The synergetic interaction between Ce and V species by forming V–O–Ce bridges enhanced the reducibility of VCe WTi catalyst and thus improved the low-temperature activity. The sulfur poisoning mechanism was also presented on a basis of the designed TPDC(temperature-programmed decomposition) and TPSR(temperatureprogrammed surface reaction) experiments. The deposition of(NH4)2SO4on V1 Ce WTi catalyst was much smaller compared with that on V1 *** the other hand, the oxidation of SO2 to SO3was signi fi cantly promoted on the CeO2-modi fi ed catalyst, accompanied by the formation of cerium sulfates. Therefore, the deactivation of this catalyst was mainly attributed to the vanishing of the V–Ce interaction and the sulfation of active ceria.

关键词： V2O5-WO3/TiO2 Ceria NH3-SCR Low-temperature activity SO2 poisoning

Research progress in green synthesis of ammonia as hydrogen-storage carrier under‘hydrogen 2.0 economy’

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Clean Energy 2023年第1期7卷 116-131页

作者： Ge Li ziran ma Jia Zhao Jiali Zhou Shengpan Peng Yonglong Li Baodong Wang National Institute of Clean-and-Low-Carbon Energy Beijing 102211China Industrial Catalysis Institute of Zhejiang University of Technology Hangzhou 310014ZhejiangChina NICE Europe Research GmbH Stockholmer Platz 170173 StuttgartGermany

Hydrogen energy is characterized by its environmental friendliness,high efficiency,lack of carbon emissions and wide range of ***,its transportation and storage are challenges that limit further development of the hydrogen-energy *** is a carbon-free hydrogen-rich *** storage of hydrogen in ammonia has unique advantages of high energy density,easy storage and transportation,reliable safety,a mature industrial foundation and no tail-end carbon ***,industrial ammonia synthesis still heavily relies on the Haber-Bosch process,which accounts for significant energy consumption and greenhouse gas ***,the development of green and sustainable ammonia-synthesis methods is extremely important and ***,ammonia-synthesis technologies such as electrocatalysis,photocatalysis,photoelectrocatalysis and biocatalysis have successfully produced ammonia from nitrogen and water,resulting in lower *** nitrogen-reduction-reaction conditions of these methods are mild and can be carried out under ambient temperatures and atmospheric pressure with low energy ***,these methods bypass the traditional hydrogen-production section and their routes are ***,these technologies can be used to flexibly integrate renewable energy,including intermittent renewable energy,to achieve distributed ammonia *** benefits contribute to both global energy and environmental sustainability *** this study,the mechanisms of ammonia synthesis under ambient conditions are reviewed and the technical difficulties of various catalysts for ammonia synthesis are *** on the optimization strategies reported for various catalysts,the high-performing catalysts reported for ammonia synthesis are reviewed and the developmental trend of this field has been forecasted.

关键词： hydrogen 2.0 economy ammonia synthesis catalyst ambient conditions mechanism

Novel synthesis of fly-ash-derived Cu-loaded SAPO-34 catalysts and their use in selective catalytic reduction of NO with NH3

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Green Energy & Environment 2019年第4期4卷 470-482页

作者： Ge Li Baodong Wang Qi Sun Wayne Qiang Xu ziran ma Hongyan Wang Daojun Zhang Jiali Zhou National Institute of Clean-and-Low-Carbon Energy

A combined acid–alkali hydrothermal method was used to prepare fly ash–derived SAPO-34 molecular sieves from a thermal power plant in Inner Mongolia(China).The specific surface area of the prepared fly-ash-derived SAPO-34 molecular sieves was 579 m^2 g^-1,the total pore volume was about 0.27 cm^3 g^-1,and the pore size was 0.56 nm;the molar ratios of Al2O3:P2O5:SiO2 were 1:0.86:***/SAPO-34 catalysts were prepared by impregnation of low-cost fly-ash-derived SAPO-34 molecular sieves as a support and tested in selective catalytic reduction with NH3(NH3-SCR).Powder X-ray diffraction(XRD),N2 adsorption–desorption,X-ray photoelectron spectroscopy(XPS),H2 temperatureprogrammed reduction(H2-TPR),NH3 temperature-programmed desorption(NH3-TPD),electron paramagnetic resonance(EPR),nuclear magnetic resonance(NMR),X-ray fluorescence analysis(XRF)and scanning electron microscopy(SEM)were used for catalyst characterization and investigation of the relationships between the catalyst structure and the catalytic *** actual silica:alumina ratio of the molecular sieves did not increase with increasing Cu loading,indicating that increasing the Cu loading does not change the original structure of the SAPO-34 molecular *** XRF and NMR results showed that replacement by Cu results in more Si *** molecular sieve acidity decreased because of the increased number of Si *** NH3-TPD results showed that for the Cu/SAPO-34 catalysts there was a low correlation between the low-temperature activity and the amount of acidic *** activity is closely related to the location of *** 4.47 Cu/SAPO-34 catalyst has the highest isolated Cu2+showed the highest NH3-SCR activities(>90%)at 250–350℃.This work opens up new avenues for recycling fly ash formed in coal-fired power plants(reducing environmental pollution)and developing low-cost SCR catalysts for NOx pollution control.

关键词： Fly-ash-derived SAPO-34 Low-temperature NH3-SCR Cu/SAPO-34 Cu content Cu species

VxMn(4-x)Mo3Ce3/Ti catalysts for selective catalytic reduction of NO by NH3

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Journal of Environmental Sciences 2020年第2期32卷 145-154页

作者： Daojun Zhang ziran ma Baodong Wang Tao Zhu Duan Weng Xiaodong Wu Hongyan Wang Ge Li Jiali Zhou National Institute of Clean-and-Low-Carbon Energy Beijing 102211China School of Chemical&Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Advanced materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

A series of vanadium based catalysts(VxMn(4-x)Mo3Ce3/Ti) with different vanadium(x wt.%) and manganese((4-x) wt.%) contents have been prepared by the wet impregnation method and investigated for selective catalytic reduction(SCR) of NOx by NH3 in the presence of 8 vol.% H2O and 500 ppm V *** physicochemical characteristics of the catalysts were thoroughly *** SCR of NOx by NH3(NH3-SCR) activity, especially the low-temperature activity, significantly increased with increasing V2O5 content in the catalyst until the V2O5 content reached 1.5 wt.%, which corresponds well with the redox properties of the *** of the metal oxides were well dispersed and strongly interacted with each other on the catalyst surface.V mainly exists in the V^5+state in the *** strong synergistic effect between the vanadium and cerium species led to formation of more Ce^3+species, and that between the vanadium and manganese species contributed to formation of more manganese species with low *** of the catalysts exhibited strong acidity, while the redox properties determined the NH3-SCR activity, especially the low-temperature activity.H2O and SO2 had severe inhibiting effects on the activity of V1.5Mn2.5Mo3Ce3/***, good H2O and SO2 resistance and high NOx conversion by V1.5Mn2.5Mo3Ce3/Ti could be achieved in the presence of SO2 and almost no decline was observed in a long-term test at 275℃ for 168 hr in the presence of SO2 and H2O, which can be attributed to the sulfate species formed on the catalyst surface.

关键词： Selective catalytic reduction Vanadium Molybdenum manganese Cerium

New Problems of Boiler Corrosion after Coupling Combustion of Coal and Biomass and Anti-Corrosion Technologies

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Journal of Renewable materials 2024年第4期12卷 799-814页

作者： Lei Wang ziran ma Chunlin Zhao Jiali Zhou Hongyan Wang Ge Li Ningling Zhou National Institute of Clean-and-Low-Carbon Energy Beijing102211China Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy&EnvironmentSoutheast UniversityNanjing210096China

This study explores the corrosion issues arising from the coupled combustion of coal and biomass and proposes potential ***,as a renewable energy source,offers advantages in energy-saving and carbon ***,the corrosive effects of alkali metal compounds,sulfur(S)and chlorine(Cl)elements in the ash after combustion cannot be underestimated due to the high volatile content of biomass *** investigate the corrosion mechanisms,as well as the transfer of Cl and alkali metal elements during this *** corrosion analyses are conducted among coal-fired boilers,pure biomass boilers and boilers with coupled *** biomass types in co-firing are studied to understand different corrosion *** main factors influencing corrosion include the physicochemical properties of biomass feedstock,furnace temperature and heating surface materials,with the chemical composition and ash content of biomass playing a dominant ***,the methods used for anti-corrosion include water washing pretreatment of biomass feedstock,application of novel alloys and coatings and the development of additives to inhibit fouling,ash deposition and *** inhibitors are economical and easy to ***,biomass can be converted into biomass gasification gas,although challenges related to tar still need to be addressed.

关键词： Biomass coupled combustion corrosion mechanism anti-corrosion measures

Effect of manganese and/or ceria loading on V_2O_5-MoO_3/TiO_2 NH_3 selective catalytic reduction catalyst

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Journal of Rare Earths 2020年第7期38卷 725-734,I0002页

作者： Daojun Zhang ziran ma Baodong Wang Tao Zhu Duan Weng Xiaodong Wu Jingyun Chen Hongyan Wang Ge Li Jiali Zhou National Institute of Clean-and-Low-Carbon Energy Beijing 102211China School of Chemical&Environmental Engineering China University of Mining&Technology(Beijing)Beijing 100083China Key Laboratory of Advanced materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

The effect of manganese and/or ceria loading of V2 O5-MoO3/TiO2 catalysts was investigated for selective catalytic reduction(SCR) of NOx by *** manganese and/or ceria loaded V2 O5-MoO3/TiO2 catalysts we re prepared by the wetness impregnation *** physicochemical characteristics of the catalysts were thoroughly *** catalytic performance of 1.5 wt% V2 O5-3 wt% MoO3/TiO2(V1.5 Mo3/Ti) is greatly enhanced by addition of 2.5 wt% MnOx and 3.0 wt% CeO2(V1.5 Mo3 Mn2.5 Ce3/Ti) below450℃.Compared with the V1.5 Mo3/Ti catalyst with NOx conversion of 75% at 275 ℃,V1.5 Mo3 Mn2.5 Ce3/Ti exhibits higher NOx conversion of 84% with good resistance to SO2 and H2 O at a gas hourly space velocity value of 150000 *** active manganese,cerium,molybdenum,and vanadium oxide species are highly dispersed on the catalyst surface and some synergistic effects exist among these *** of MnOx significantly enhances the redox ability of the cerium,vanadium,and molybdenum *** of Ce increases the acidity of the *** active oxygen species,including surface chemisorbed oxygen,form with addition of Mn and/or *** of the synergistic effects,appropriate proportions of manganese in different valence states exist in the *** summary,the good redox ability and the strong acidity contribute to the high NH3-SCR activity and N2 selectivity of the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst in a wide temperature *** the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst shows good resistance to H2 O and SO2 in long-time catalytic testing,which can be ascribed to the highly sulfated species adsorbed on the catalyst.

关键词： Selective catalytic reduction Vanadium Molybdenum manganese Cerium Rare earths

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活化液助溶剂对再生脱硝催化剂性能的影响

化工进展 2022年第8期41卷 4173-4180页

作者：马静马子然林德海马少丹王宝冬北京低碳清洁能源研究院北京102211

:为了考察助溶剂对活化液的催化剂再生性能的影响,将某燃煤电厂失活退役的脱硝催化剂在相同清洗工艺下处理,随后分别浸入以草酸、乙醇胺作为助溶剂配制的活化液中,得到两个再生催化剂。采用XRF、氮气物理吸附法、原位吡啶吸附、NH_(3)-... 详细信息

:为了考察助溶剂对活化液的催化剂再生性能的影响,将某燃煤电厂失活退役的脱硝催化剂在相同清洗工艺下处理,随后分别浸入以草酸、乙醇胺作为助溶剂配制的活化液中,得到两个再生催化剂。采用XRF、氮气物理吸附法、原位吡啶吸附、NH_(3)-TPD、Raman、XPS、H_(2)-TPR以及固定床脱硝反应器等表征手段对新鲜样品、失活样品以及再生样品进行表面理化性质、脱硝性能测试评价。结果显示,脱硝催化剂失活的主要原因是飞灰中的碱金属K、Na造成催化剂的比表面积和孔容下降、表面Lewis酸性位数量减少、V^(5+)比例下降、活性VO_(x)减少及氧化还原性能下降。同时发现,两个再生催化剂在等量活性组分钒条件下,脱硝性能却表现出较大差异,乙醇胺助溶活化液再生的样品Ethanol-cat性能恢复至新鲜催化剂的97%以上,而草酸助溶活化液再生的样品Oxalic-cat却几乎无再生效果,这是因为两种活化液中的活性组分钒状态不同,乙醇胺助溶活化液中钒离子可有效恢复失活催化剂的酸性位数量、V^(5+)比例、活性物种VO_(x)数量以及氧化还原性能,而草酸助溶活化液对失活催化剂的这些理化性质作用较小。

关键词：再生活化液助溶剂脱硝催化剂失活机理

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WO_(x)/CeO_(2)蜂窝脱硝催化剂的性能及反应机制研究

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中国稀土学报 2023年第5期41卷 862-875,I0001页

作者：吕雪婷马子然吴晓东王宝冬北京低碳清洁能源研究院北京昌平102211 清华大学材料学院新型陶瓷与精细工艺国家重点实验室北京100084

传统的V_(2)O_(5)-WO_(3)/TiO_(2)商业催化剂由于具有毒性、选择性较差、催化活性温度窗口较窄的缺点,已经不能适应中国“双碳”目标下的NO_(x)排放控制日益严格的要求。因此,开发具有更宽温度窗口且环境友好的新型催化剂成为了目前科... 详细信息

传统的V_(2)O_(5)-WO_(3)/TiO_(2)商业催化剂由于具有毒性、选择性较差、催化活性温度窗口较窄的缺点,已经不能适应中国“双碳”目标下的NO_(x)排放控制日益严格的要求。因此,开发具有更宽温度窗口且环境友好的新型催化剂成为了目前科学界和产业界研究的热点。本文利用CeO_(2)优异催化特性,通过WO_(3)负载改性开发了WO_(x)/CeO_(2)蜂窝脱硝催化剂,在GHSV=30000 h^(-1)的高空速条件下,含10%WO_(3)的WOx/CeO_(2)催化剂可实现在210~490℃内NO_(x)转化率在80%以上,具有较宽的温度操作窗口和超过95%的N2选择性。通过对催化剂的材料表征和动力学实验研究,揭示了WO_(3)与CeO_(2)的相互作用机制及其对于NH_(3)-SCR催化反应的促进作用。WCe催化剂的NH3-SCR反应遵循Eley-Rideal途径,负载形成的WO_(x)物种提供较多的强酸性位,促进催化剂对NH3的吸附及活化并与NO反应的过程。同时WO_(3)与CeO_(2)的电子相互作用降低了CeO_(2)中表面活性氧的含量,抑制了对NH3的非选择性氧化,促使高温区SCR活性和选择性明显提高。

关键词：脱硝蜂窝催化剂 WO_(3) CeO_(2) 反应机制