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Ce-modified USY zeolite catalysts for catalytic oxidation of chlorinated VOCs:Effect of the location of CeO2 and its synergistic effect with USY zeolite

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Journal of Rare Earths 2024年第11期42卷 2068-2077页

作者： Xiaolin Guo Zhiming Li Ang Zhou yijun shi Yong Wang Renxian Zhou Institute of Catalysis Zhejiang University College of Materials and Chemistry China Jiliang University

The catalytic behavior of a catalyst for chlorine-containing volatile organic compounds（CVOCs） oxidation largely depends on the synergistic interaction between the oxidizing and acidic *** the present work,two catalysts with different distributions of CeO2on the inner and outer surfaces of 4.0Ce-USY-ex and 4.0Ce-USY-dp（USY zeolite） were prepared respectively by ion exchange and deposition methods,with a purpose of finding out how the location of the oxidation sites（CeO2） influence its synergistic effect with the acidic sites of *** results show that 4.0Ce-USY-ex is much more active for catalytic degradation of 1,2-dichloroethane（DCE）,while 4.0Ce-USY-dp catalyst exhibit higher catalytic degradation activity for other structured CVOCs(dichloromethane（DCM）,trichloroethylene（TCE）,chlorobenzene（CB）).CeO2in 4.0Ce-USY-ex catalyst mainly disperses in the pore channels of USY zeolite,and there are many strong acid centers on the surface,which is conducive to the dechlorination conversion of ***,CeO2in 4.0Ce-USY-dp catalyst is mainly distributed on the outer surface of USY and has strong oxidation ability,which contributes to the deep oxidation of ***,the presence of a large number of strong acid centers on the catalyst surface of 4.0Ce-USY-ex catalysts leads to severe accumulation of surface carbon species and significantly decreases its stability towards ***,a large number of active oxygen species on the surface of 4.0Ce-USY-dp and CeO2catalysts are beneficial to the deep oxidation of DCE,reducing the formation of surface carbon and thus improving the stability of the ***,the influence of the location of the oxidation sites on its synergistic effect with the acidic sites was established in the present work,which could provide some new ideas for the rational design of CVOCs degradation catalyst with appropriate distribution of active sites.

关键词： CeO2 CVOCs oxidation Location Rare earths Synergistic effect USY

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面向气候风险的长三角中心区城市韧性评估及时空演变

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上海城市规划 2024年第3期3卷 143-150页

作者：李航施益军徐丽华浙江农林大学风景园林与建筑学院浙江农林大学风景园林与建筑学院党委

全球气候变化带来更强的气候风险,对城市韧性评价能够找出城市发展中应对风险的薄弱环节并提出改进的意见。从气候风险视角出发分析城市在面对多种灾害风险下的韧性变化,从承灾体脆弱性、孕灾环境敏感性、致灾因子危险性和防灾减灾能力... 详细信息

全球气候变化带来更强的气候风险,对城市韧性评价能够找出城市发展中应对风险的薄弱环节并提出改进的意见。从气候风险视角出发分析城市在面对多种灾害风险下的韧性变化,从承灾体脆弱性、孕灾环境敏感性、致灾因子危险性和防灾减灾能力4个维度构建气候风险下的韧性评估体系,提供理论基础。通过构建基于投影寻踪的遗传算法模型和耦合激励评价模型进行非线性评估,对长三角中心区2010-2021年间的相关指标和综合韧性进行评价,分析影响城市韧性变化的主要影响因素,识别其分布的时空演变特征。最后根据结果提出长三角中心区城市韧性提升的建议,为相关研究提供借鉴。

关键词：气候风险时空演变城市韧性耦合激励法非线性评估

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Transition metaldoping effect and high catalytic activity of CeO_(2)-TiO_(2) for chlorinated VOCs degradation

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Journal of Rare Earths 2022年第5期40卷 745-752,I0003页

作者： yijun shi Xiaolin Guo Zhinan shi Renxian Zhou Institute of Catalysis Zhejiang UniversityHangzhou 310028China College of Materials and Chemistry China Jiliang University Hangzhou 310018China

A series of transition metals(Fe,Co,Ni,Cu,Cr and Mn)-doped CeO_(2)-TiO_(2) catalysts were prepared by the sol-gel method and applied for the catalytic removal of 1,2-dichloroethane(DCE) as a model for chlorinated VOCs(CVOCs).The various characterization methods including X-ray diffraction(XRD),N_(2) adsorption-desorption,UV-Raman,NH_(3) temperature-programmed desorption(NH_(3)-TPD) and H_(2) temperature-programmed reduction(H_(2)-TPR) were utilized to investigate the physicochemical properties of the *** results show that doping Fe,Co,Ni or Mn can obviously promote the activity of CeO_(2)-TiO_(2) mixed oxides for DCE degradation,which is related to their improved texture properties,acid sites(especially for strong acidity) and low-temperature ***,CeTi-Fe doped with moderate Fe exhibits excellent activity for 1,2-dichloroethane(DCE) degradation,giving a T_(90%) value as low as 250℃.More importantly,only trace chlorinated byproducts were produced during the low-temperature degradation of various CVOCs(dichloromethane(DCM),trichloroethylene(TCE) and chlorobenzene(CB)) over CeTi-Fe1/9 catalyst with high durability.

关键词： Transition metals doping CeO_(2)-TiO_(2)mixed oxides CVOCs degradation High activity Excellent durability Rare earths

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Nanolubricant additives: A review

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Friction 2021年第5期9卷 891-917页

作者： Jun ZHAO Yiyao HUANG Yongyong HE yijun shi College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Division of Machine Elements LuleåUniversity of TechnologyLuleå97187Sweden

Using nanoadditives in lubricants is one of the most effective ways to control friction and wear,which is of great significance for energy conservation,emission reduction,and environmental *** the scientific and technological development,great advances have been made in nanolubricant additives in the scientific research and industrial *** review summarizes the categories of nanolubricant additives and illustrates the tribological properties of these *** on the component elements of nanomaterials,nanolubricant additives can be divided into three types:nanometal-based,nanocarbon-based,and nanocomposite-based *** dispersion stabilities of additives in lubricants are also discussed in the review *** affecting factors and effective dispersion methods have been investigated in ***,the review summarizes the lubrication mechanisms of nanolubricant additives including tribofilm formation,micro-bearing effect,self-repair performance,and synergistic *** addition,the challenges and prospects of nanolubricant additives are proposed,which guides the design and synthesis of novel additives with significant lubrication and antiwear properties in the future.

关键词： nanolubricant additive dispersion stability tribological properties lubrication mechanism

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应对高温天气的城市冷却网络构建策略及经验启示——以美国波士顿为例

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上海城市规划 2024年第4期4卷 165-172页

作者：石宇航施益军汤俊卿徐丽华吴亚琪冯矛浙江农林大学风景园林与建筑学院北京大学城市规划与设计学院

随着近年来高温事件的频发,高温天气成为影响城市居民生命财产安全的重要因素之一,城市冷却空间作为抵御城市发生极端高温事件的重要措施,构建城市冷却空间网络能够有效缓解城市极端高温天气对城市居民所带来的负面影响。以美国波士顿为... 详细信息

随着近年来高温事件的频发,高温天气成为影响城市居民生命财产安全的重要因素之一,城市冷却空间作为抵御城市发生极端高温事件的重要措施,构建城市冷却空间网络能够有效缓解城市极端高温天气对城市居民所带来的负面影响。以美国波士顿为例,回顾其应对高温天气的规划历程,总结其构建城市冷却空间网络的要点和具体方法,借鉴其高温风险评估、冷却斑块评估识别、绿色廊道连接、城市冷却网络构建和冷却网络运行维护等方面的经验,并针对我国高温城市提出相应的经验启示和规划建议。

关键词：高温天气城市冷却空间网络经验启示波士顿

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Synergistic effect of Pt nanoparticles and micro-mesoporous ZSM-5 in VOCs low-temperature removal

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Journal of Environmental Sciences 2021年第9期33卷 87-97页

作者： Jialu Wang Xiaolin Guo yijun shi Renxian Zhou Institute of Catalysis Zhejiang UniversityHangzhou 310028China College of Materials and Chemistry China Jiliang UniversityHangzhou 310018China

Micro-mesoporous ZSM-5 zeolites were obtained by the post-treatment of tetrahydroxy ammonium hydroxide(TPAOH) solution with different *** hierarchical pore structure formed during the desilication process facilitates the dispersion of Pt nanoparticles and Pt/ZSM-5 catalysts exhibit rather high catalytic activity for the deep oxidation of various VOCs at low *** catalyst treated with TPAOH of 0.1 mol/L(Pt/ZSM-5(0.1)) shows the lowest degradation temperature(T90%) of 128 and 142℃, respectively for benzene and *** with the untreated Pt/ZSM-5 catalyst, the abundant mesopores, small Pt particle size and finely dispersed Pt contribute to the superior catalytic activity and stability of the Pt/ZSM-5 catalysts for VOCs *** importantly, the existence of H_(2)O in the feed gases hardly affected the activity of Pt/ZSM-5(0.1) catalyst at the low reaction temperature of 128℃, which is very important for VOCs low-temperature removal in the future practical applications.

关键词： Pt/ZSM-5 catalysts Micro-mesoporous ZSM-5 VOC oxidation Synergistic effect

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Low-temperature VOCs oxidation performance of Pt/zeolites catalysts with hierarchical pore structure

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Journal of Environmental Sciences 2023年第2期124卷 505-512页

作者： Jialu Wang yijun shi Fanzhe Kong Renxian Zhou Institute of Catalysis Department of ChemistryZhejiang UniversityHangzhou 310028China

Different zeolites supported Pt catalystswithmicro-mesoporous structurewere prepared by organic base tetrapropylammonium hydroxide(TPAOH)treatment and their catalytic oxidation activity for various volatile organic compounds(VOCs)were *** results reveal that the synergistic effect between Pt nanoparticles and surface acid sites plays an important role in VOCs low-temperature *** small size and high dispersion of Pt nanoparticles on the surface of the zeolites would promote the catalytic oxidation of aromatics and alkanes over the Pt/zeolite catalysts,while strong acidity and abundant acid sites of catalysts are in favour of the oxidation of the VOCs *** addition,it was found that Pt/ZSM-5 catalyst exhibits the highest oxidation activity for various VOCs low-temperature removal amongst all the catalysts due to the balance of both Pt dispersion and abundant acid sites in the *** comprehensive consideration should be very helpful when designing and preparing novel catalysts for the low-temperature removal of VOCs.

关键词： Pt/zeolites catalyst Hierarchical pore zeolites VOCs oxidation Synergistic effect

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Effects of fibrous fillers on friction and wear properties of polytetrafluoroethylene composites under dry or wet conditions

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China Particuology 2007年第6期5卷 414-419页

作者： Huaiyuan Wang Xin Feng yijun shi Xiaohua Lu State Key Laboratory of Materials-oriented Chemical Engineering Nanjing University of Technology Nanjing 210009 China

The friction and wear behavior and mechanism as well as the mechanical properties of polytetrafluoroethylene （PTFE） composites filled with potassium titanate whiskers （PTW） and short carbon fibers （CF） under dry, wet and alkaline conditions were investigated. Experiments indicated that owing to appropriate cooling and boundary lubricating effects, the filled PTFE composites showed much lower frictional coefficient and better wear resistance under alkaline than dry and wet sliding conditions. The wear resistance of carbon-fiber-filled PTFE was much better than that of potassium titanate-whisker-filled PTFE composites in water. Results also showed that the transfer film on counterpart rings was significantly hindered by water and alkali. Hydrophilic-filler-reinforced PTFE composites yield higher wear rate when sliding under water.

关键词： PTFE composites Whiskers Carbon fibers Friction and wear properties Alkaline solution

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New insight into the design of highly dispersed Pt supported CeO_(2)-TiO_(2) catalysts with superior activity for VOCs low-temperature removal

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Green Energy & Environment 2023年第6期8卷 1654-1663页

作者： yijun shi Xiaolin Guo Yiyan Wang Fanzhe Kong Renxian Zhou Institute of Catalysis Department of ChemistryZhejiang UniversityHangzhou310028China College of Materials and Chemistry China Jiliang UniversityHangzhou310018China

A series of CeO_(2)-TiO_(2)mixed oxides supports with various Ce/Ti molar ratio were synthesized by modified coprecipitation method. The corresponding Pt loaded(0.5 wt% Pt) catalysts were prepared by electronless deposition method and evaluated for the deep oxidation of n-hexane as a model VOCs. The results show that the CeO_(2)and TiOxnanoparticles can highly disperse into each other and form Ce_(2)Ti_(2)O_(7)solid solution with appropriate Ce/Ti molar ratio, which significantly improves their redox ability by enhancing the interaction between CeO_(2)and TiO_(x). The dispersibility of Pt species can also be adjusted by altering the Ce/Ti molar ratio, and Pt/CeTi-2/1 catalyst with Ce/Ti molar ratio of 2:1 exhibits the best Pt dispersibility that Pt species mainly exist as Pt single atoms. The high dispersion of Pt species in the Pt/CeO_(2)-TiO_(2)catalysts would promote the catalytic activity of VOCs oxidation with low T90% values(1000 ppm, GHSV = 15,000 h^(-1)), such as for n-hexane degradation with T90% of 139℃. The characterizations reveal that the superior activity is mainly related to possessing the more Pt2+species,adsorbed oxygen species and higher low-temperature reducibility owing to the strong interaction between highly dispersed Pt species and CeO_(2)-TiO_(2)as well as the promoted migration of lattice oxygen by the formation of more Ce_(2)Ti_(2)O_(7)species. Furthermore, the Pt/CeTi-2/1 catalyst also exhibits excellent stability for chlorinated and other non-chlorinated VOCs oxidation, making it very promising for real application under various operating conditions.

关键词： Highly dispersed Pt species CeO_(2)–TiO_(2)mixed oxides VOCs degradation Superior activity

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杭州城市空间增长与生态系统服务价值损益关联

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现代城市研究 2024年第3期39卷 110-115页

作者：夏兆煊马淇蔚徐丽华施益军陆张维浙江农林大学风景园林与建筑学院

当前我国正处于城镇化高质量转型的关键时期,明晰城市空间增长与生态系统服务价值(ESV)损益的相互关系对于城市可持续发展具有重要意义。以我国典型的山水城市—杭州为例,基于多源数据,采用空间增长定量解析法、价值当量评估、四象限分... 详细信息

当前我国正处于城镇化高质量转型的关键时期,明晰城市空间增长与生态系统服务价值(ESV)损益的相互关系对于城市可持续发展具有重要意义。以我国典型的山水城市—杭州为例,基于多源数据,采用空间增长定量解析法、价值当量评估、四象限分析模型,阐明城市空间增长和ESV损益的规模强度变化,以此揭示二者空间关系,明确空间关系类型。结果表明:(1)从总体规模和强度特征来看,杭州城市空间增长和ESV损益存在错配现象,即规模上的此消彼长和强度上的同增共减;(2)从空间特征来看,城市空间与ESV的重心整体呈东西相向而行的剧烈转移态势,在方位上增长强度与ESV损耗程度表现为东部一致而西部分歧;(3)增长强度与ESV损耗程度存在高—高、高—低、低—低、低—高4类关系且作用空间存在差异,这是由各类型城市发展政策所致。基于此,提出城市空间增长和ESV保值增益的协同发展策略,以期为城市绿色高质量发展提供决策依据。

关键词：生态系统服务价值城市空间增长空间政策四象限分析杭州

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