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Novel Co-Mg-Al-Ti-O catalyst derived from hydrotalcite-like compound for NO storage/decomposition

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Journal of Environmental Sciences 2012年第3期24卷 488-493页

作者： Jie Cheng Xiaoping Wang Chunyan Ma zhengping hao Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

Catalysts of Co1.5Mg1.5/Al0.9Ti0.1O and Co1.5Mg1.5/AlO were successfully prepared by calcinations of corresponding hydrotalcite-like compounds at 800°C for 4 hr. The derived oxides were of spinel phase and a small quantity of Ti substitution did not change the crystal purity. Their catalytic performance for the NO storage/decomposition was investigated. Ti incorporation enhanced the NO decomposition activity while has an opposite effect on the storage capacity of catalyst. In situ FT-IR spectra of the catalysts showed that the final adsorption species on the catalysts was coordinated nitrates/nitrites. In addition, NO storage/decomposition mechanism has been discussed on the basis of these observations.

关键词： NO decomposition storage hydrotalcite-like compounds

Ceria-Modified Clay Supported Palladium Catalysts for Complete Oxidation of Volatile Organic Compounds

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Journal of Rare Earths 2004年第Z1期22卷 178-180页

作者： Li Jinjun hao zhengping Hu Chun Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Ceria- and alumina-pillared interlayered clays were synthesized in the presence of PEO surfactant by using laponite clay as raw *** the synthesized pillared clays were used as supports to load palladium catalysts for complete oxidation of *** adsorption/desorption experiments reveal that the pillared clays have higher tests show that ceria pillar exhibited promoting effect on the activity of the palladium catalysts, and ceria-pillared clay supported palladium catalyst catalyzed the complete oxidation of benzene at less than 250 ℃.The calcination temperature affects the activity of the catalysts significantly, and it is found that the optimal calcination temperature are 600 and 400 ℃ for ceria- and alumina-pillared clay supported palladium catalysts, respectively.

关键词： ceria pillared clays palladium catalysts VOCs catalytic complete oxidation

La_(2)FeMO_(6)双钙钛矿中的不对称氧空位用于促进氧活化和H2S选择性氧化

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Chinese Journal of Catalysis 2024年第7期62卷 198-208页

作者：魏征蒋国霞王怡雯黎刚刚张中申程杰张凤莲郝郑平中国科学院大学挥发性有机物污染控制材料与技术国家工程实验室环境材料与污染控制技术研究中心北京101408

金属氧化物催化剂表面O_(2)分子的活化对于多相催化中氧化还原反应具有重要意义.硫化氢(H_(2)S)选择性氧化是一个典型的氧化反应,通常用于去除克劳斯工艺尾气中有害的H_(2)S,同时回收化工产品硫磺.受克劳斯反应的热力学限制,工艺尾气中... 详细信息

金属氧化物催化剂表面O_(2)分子的活化对于多相催化中氧化还原反应具有重要意义.硫化氢(H_(2)S)选择性氧化是一个典型的氧化反应,通常用于去除克劳斯工艺尾气中有害的H_(2)S,同时回收化工产品硫磺.受克劳斯反应的热力学限制,工艺尾气中仍有近1%的H_(2)S残留,在焚烧炉中会转化为有害的SO_(x),造成不必要的硫损失以及严重的环境问题.研究表明,氧分子活化解离产生的活性氧物种是H_(2)S选择氧化的关键活性物种.然而,受限于氧分子的低效活化,传统催化剂需提高反应温度以获得令人满意的H_(2)S转化率,这也促进了副反应的进行并生成有害副产物SO_(2).因此,迫切需要在较低温度下实现氧分子的高效活化以促进H_(2)S选择氧化反应的进行,从而最大限度地提高克劳斯工艺硫回收效率并降低运营成本.目前,大多数研究通过引入更多的氧空位促进氧分子的活化及氧化反应的进行,但很少有人考虑氧空位本身结构的影响.近年来,研究者更多地关注不对称氧/空位(M_(1)-O-M_(2)或M_(1)-VO-M_(2)),该特殊结构可以有效地优化氧分子的活化,提高催化性能.本文报道了一种简单的氧空位调控策略用于H_(2)S选择氧化,通过过渡金属(M=Mn,Co和Mo)取代策略在LaFeO_(3)钙钛矿催化剂中引入不对称氧空位,从而激发氧分子活化以促进H_(2)S选择氧化的进行.X射线粉末衍射、Raman光谱及透射电镜结果表明,Mn和Co的引入形成了均匀的La_(2)FeMO_(6)以及La_(2)FeCoO_(6)双钙钛矿相,而Mo的引入则形成了La_(2)Mo_(2)O_(9)和LaFeO_(3)钙钛矿的混相.X射线光电子能谱及M?ssbauerr谱结果表明,Mn取代形成的La_(2)FeMO_(6)双钙钛矿催化剂由于其结构中Mn与Fe的完全交替取代形成了丰富的不对称Fe-VO-Mn位点,结合H_(2)程序升温还原及O_(2)程序升温解吸结果,可以推断不对称空位促进了催化剂上氧分子的活化,进而提高了催化剂的氧迁移率和还原性.模拟计算了氧分子在LaFeO_(3)及La_(2)FeMO_(6)催化剂上的吸附及解离过程,结果表明,氧分子在对称的Fe-VO-Fe位点上具有较高的吸附能及解离能,在不对称的Fe-VO-Mn位点上不存在稳定的吸附态,倾向于直接解离形成活性氧物种.具有丰富不对称Fe-VO-Mn位点的La_(2)FeMO_(6)催化剂的H_(2)S选择氧化低温活性和稳定性显著提高,在较宽的温度窗口内均可保持较好的H_(2)S转化率(>90%)与硫选择性(接近100%).综上,本文通过取代策略实现了对催化剂氧空位结构的调控,揭示了不对称氧空位对氧分子活化行为的促进机制.研究结果不仅为合理设计高效氧化催化剂探明了一条可行的途径,还对氧分子活化过程中氧空位结构的促进机制提供了深入的见解,有望激发更多关于开发氧化还原反应高效催化材料的研究.

关键词：双钙钛矿不对称氧空位氧分子活化硫化氢选择性氧化硫磺回收

Adsorption and membrane separation for removal and recovery of volatile organic compounds

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Journal of Environmental Sciences 2023年第1期123卷 96-115页

作者： Guoqiang Gan Shiying Fan Xinyong Li Zhongshen Zhang zhengping hao State Key Laboratory of Fine Chemicals Key Laboratory of Industrial Ecology and Environmental Engineering(MOE)School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Volatile organic compounds(VOCs)are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity,high volatility,and poor *** is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent *** China,clear directions and requirements for reduction of VOCs have been given in the“national plan on environmental improvement for the 13th Five-Year Plan period”.Therefore,the development of efficient technologies for removal and recovery of VOCs is of great *** technologies are favored by researchers due to their advantages in both recycling VOCs and reducing carbon *** them,adsorption and membrane separation processes have been extensively studied due to their remarkable industrial *** overview was to provide an up-to-date progress of adsorption and membrane separation for removal and recovery of ***,adsorption and membrane separation were found to be the research hotspots through bibliometric ***,a comprehensive understanding of their mechanisms,factors,and current application statuses was ***,the challenges and perspectives in this emerging field were briefly highlighted.

关键词： Volatile organic compounds(VOCs) Removal and recovery technology Adsorption Membrane separation Bibliometric analysis

Effects of metal and acidic sites on the reaction by-products of butyl acetate oxidation over palladium-based catalysts

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Journal of Environmental Sciences 2014年第3期26卷 702-707页

作者： Lin Yue Chi He zhengping hao Shunbing Wang Hailin Wang Department of Environmental Nano-materials Research Center for Eco-Environmental SciencesChinese Academy of Sciences The Administrative Center for China's Agenda 21 National Urban Environmental Pollution Control Engineering Techniques Research Center Beijing Municipal Research Institute of Environmental Protection

Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption- desorption, X-ray fluorescence （XRF）, HE temperature programmed reduction （H2-TPR）, and NH3 temperature programmed desorption （NH3-TPD）. Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2- methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from iso4merization and protolysis reactions.

关键词： catalytic oxidation butyl acetate reaction by-product Pd/ZSM-5 VOCs

A review of whole-process control of industrial volatile organic compounds in China

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Journal of Environmental Sciences 2023年第1期123卷 127-139页

作者： Hailin Wang Shumei Sun Lei Nie Zhongshen Zhang Wenpeng Li zhengping hao Beijing Key Laboratory for Urban Atmospheric VOCs Pollution Control and Technology Application Beijing Municipal Research Institute of Environmental ProtectionBeijing 100037China College of Resources Environment and Tourism Capital Normal UniversityBeijing 100048China National Engineering Laboratory for VOCs Pollution Control Material&Technology Research Center for Environmental Material and Pollution Control TechnologyUniversity of Chinese Academy of SciencesBeijing 101408China

Volatile organic compounds(VOCs)play an important role in the formation of ground-level ozone and secondary organic aerosol(SOA),and they have been key issues in current air pollution prevention and control in *** attention has been paid to industrial activities due to their large and relatively complex VOCs *** present research aims to provide a comprehensive review on whole-process control of industrial VOCs,which mainly includes source reduction,collection enhancement and end-pipe *** VOCs materials including water-borne ones are the keys to source substitution in industries related to coating and solvent usage,leak detection and repair(LDAR)should be regarded as an efficient means of source reduction in refining,petrochemical and other chemical *** types of VOCs collection methods such as gas-collecting hoods,airtight partitions and others are discussed,and airtight collection at negative pressure yields the best collection *** end-pipe treatments like UV oxidation,low-temperature plasma,activated carbon adsorption,combustion,biodegradation,and adsorption-combustion are discussed in ***,several recommendations are made for future advanced treatment and policy development in industrial VOCs emission control.

关键词： Volatile organic compounds Materials substitution Collection enhancement End-pipe treatments

Catalytic activities and mechanism of formaldehyde oxidation over gold supported on MnO2 microsphere catalysts at room temperature

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Frontiers of Environmental Science & Engineering 2016年第3期10卷 447-457页

作者： Guanglong PANG Donghui WANG Yunhong ZHANG Chunyan MA zhengping hao Institute of Chemical Physics School of Chemistry Beijing Institute of Technology Beijing 100081 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Research Institute of Chemical Defense Beijing 100191 China

MnO2 microspheres with various surface structures were prepared using the hydrothermal method, and Au/MnO2 catalysts were synthesized using the sol-gel method. We obtained three MnO2 microspheres and Au/MnO2 samples： coherent solid spheres covered with wire-like nanostructures, solid spheres with nanosheets, and hierarchical hollow microspheres with nanoplatelets and nanorods. We investigated the properties and catalytic activities of formaldehyde oxidation at room temperature. Crystalline structures of MnO2 are the main factor affecting the catalytic activities of these samples, and γ- MnO2 shows high catalytic performance. The excellent redox properties are responsible for the catalytic ability of γ-MnO2. The gold-supported interaction can change the redox properties of catalysts and accelerate surface oxygen species transition, which can account for the catalytic activity enhancement of Au/MnO2. We also studied intermediate species. The dioxymethylene （DOM） and formate species formed on the catalyst surface were considered intermediates, and were ultimately transformed into hydrocarbonate and carbonate and then decomposed into CO2. A proposed mechanism of formaldehyde oxidation over Au/MnO2 catalysts was also obtained.

关键词： MnO2 microspheres Au/MnO2 formaldehyde oxidation γ-MnO2

Layered sphere-shaped TiO_2 capped with gold nanoparticles on structural defects and their catalysis of formaldehyde oxidation

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Journal of Environmental Sciences 2016年第1期28卷 77-85页

作者： Chunyan Ma Guanglong Pang Guangzhi He Yang Li Chi He zhengping hao Department of Environmental Nano-materials Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Department of Environmental Science and Engineering State Key Laboratory of Multiphase Flow in Power EngineeringSchool of Energy and Power Engineering Xi'an Jiaotong University

We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 *** Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet,including crystal steps and edges,thereby fixing the Au-TiO2 perimeter *** transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 *** doped Au induced the formation of oxygen vacancies in the Au-TiO2 *** vacancies are essential for generating active oxygen species（-＊O^-） on the TiO2 surface and Ti^3＋ ions in bulk *** ions can then form Ti^3＋-O^--Ti^4＋species,which are known to enhance the catalytic activity of formaldehyde（HCHO） *** studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.

关键词： Layered Au/TiO2 nanospheres Structural defects Oxygen vacancy defects Reaction mechanism Formaldehyde oxidation

Adsorption of benzene, cyclohexane and hexane on ordered mesoporous carbon

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Journal of Environmental Sciences 2015年第4期27卷 65-73页

作者： Gang Wang Baojuan Dou Zhongshen Zhang Junhui Wang Haier Liu zhengping hao Research Center for Eco-Environmental Sciences Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology Beijing

Ordered mesoporous carbon（OMC） with high specific surface area and large pore volume was synthesized and tested for use as an adsorbent for volatile organic compound（VOC）disposal. Benzene, cyclohexane and hexane were selected as typical adsorbates due to their different molecular sizes and extensive utilization in industrial processes. In spite of their structural differences, high adsorption amounts were achieved for all three adsorbates, as the pore size of OMC is large enough for the access of these VOCs. In addition, the unusual bimodal-like pore size distribution gives the adsorbates a higher diffusion rate compared with conventional adsorbents such as activated carbon and carbon molecular sieve. Kinetic analysis suggests that the adsorption barriers mainly originated from the difficulty of VOC vapor molecules entering the pore channels of adsorbents. Therefore, its superior adsorption ability toward VOCs, together with a high diffusion rate, makes the ordered mesoporous carbon a promising potential adsorbent for VOC disposal.

关键词： Volatile organic compounds Adsorption Ordered mesoporous carbon Isosteric heat of adsorption Knudsen diffusion