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Nano Research 2023年第5期16卷 6187-6199页

作者： Chao Peng Yu Ren Di Yu Lanyi Wang Chunlei Zhang Xiaoqiang Fan Xuehua Yu Zhen Zhao Yuechang Wei Jian Liu Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China

Air pollution from particulate matter produced by incomplete combustion of diesel fuel has become a serious environmental pollution problem,which can be addressed by catalytic combustion.In this work,a series of K-modified MnO_(δ)catalysts with different microstructures were synthesized by the hydrothermal method,the relationship between structure of the catalysts and their catalytic performance for soot combustion was studied by characterization techniques and density functional theory(DFT)calculations.Results showed that the prepared catalysts had good catalytic performance for soot combustion and could completely oxidize soot at temperatures below 400℃.The cryptomelane-type K_(2−x)Mn_(8)O_(16)(K-OMS-2)with tunnel structure had excellent NO oxidation capacity and abundance of Mn^(4+)ions(Mn^(4+)/Mn^(3+)=1.24)with good redox ability,it demonstrated better soot combustion performance than layered birnessite-type K_(2)Mn_(4)O_(8)(K-OL-1).The T_(10),T_(50),T_(90)temperatures of KOMS-2 were 269,314,346℃,respectively.The K-OMS-2 catalyst also showed excellent stability after five catalytic cycles,with T_(10),T_(50),T_(90)values holding in the ranges of 270±2,316±2,348±3℃,respectively.

关键词： K-modified MnO_(δ) hydrothermal method tunnel structure layered structure soot combustion

Alkali/alkaline-earth metal-modified MnO_(x) supported on three-dimensionally ordered macroporous–mesoporous Ti_(x)Si+(1-x)O_(2) catalysts:Preparation and catalytic performance for soot combustion

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Journal of Environmental Sciences 2023年第3期125卷 82-94页

作者： Chao Peng Di Yu Chunlei Zhang Maozhong Chen LanyiWang Xuehua Yu Xiaoqiang Fan Zhen Zhao Kai Cheng Yongsheng Chen YuechangWei Jian Liu Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Energy and Catalysis Laboratory Department of Mechanical and Automation EngineeringThe Chinese University of Hong KongHong KongChina

The performance of catalysts used in after-treatment systems is the key factor for the removal of diesel soot,which is an important component of atmosphericfine particle emissions.Herein,three-dimensionally ordered macroporous–mesoporous Ti_(x)Si+(1-x)O_(2)(3DOM-m Ti_(x)Si+(1-x)O_(2)) and its supported MnO_(x)catalysts doped with different alkali/alkaline-earth metals (AMnO_(x)/3 DOM-m Ti_(0.7)Si_(0.3)O_(2)(A:Li,Na,K,Ru,Cs,Mg,Ca,Sr,Ba)) were prepared by mesoporous template (P123)-assisted colloidal crystal template (CCT) and incipient wetness impregnation methods,respectively.Physicochemical characterizations of the catalysts were performed using scanning electron microscopy,X-ray diffraction,N_(2)adsorption–desorption,H_(2)temperature-programmed reduction,O_(2)temperature-programmed desorption,NO temperature-programmed oxidation,and Raman spectroscopy techniques;then,we evaluated their catalytic performances for the removal of diesel soot particles.The results show that the 3DOM-m Ti_(0.7)Si_(0.3)O_(2)supports exhibited a well-defined 3DOM-m nanostructure,and AMnO_(x)nanoparticles with 10–50 nm were evenly dispersed on the inner walls of the uniform macropores.In addition,the as-prepared catalysts exhibited good catalytic performance for soot combustion.Among the prepared catalysts,CsMnO_(x)/3DOM-m Ti_(0.7)Si_(0.3)O_(2)had the highest catalytic activity for soot combustion,with T10,T50,and T90(the temperatures corresponding to soot conversion rates of 10%,50%,and 90%) values of 285,355,and 393℃,respectively.The high catalytic activity of the CsMnO_(x)/3 DOM-m Ti_(0.7)Si_(0.3)O_(2)catalysts was attributed to their excellent low-temperature reducibility and homogeneous macroporous–mesoporous structure,as well as to the synergistic effects between Cs and Mn species and between CsMnO_(x)and the Ti_(0.7)Si_(0.3)O_(2)support.

关键词： Three-dimensionally ordered macroporous-mesoporous Ti_(0.7)Si_(0.3)O_(2) Alkali/alkaline-earth metals MnO_(x) Catalysts Preparation soot combustion

soot combustion; Ceria; Ternary mixed oxide; Cordierite coating; Diesel particulate filter

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Journal of Environmental Sciences 2018年第11期30卷 58-68页

作者： Leandro Fontanetti Nascimento Juliana Fonseca Lima Paulo Cesar de Sousa Filho Osvaldo Antonio Serra Department of Chemistry FFCLRP University of Sao Paulo 14040-901 Ribeirao Preto Sao Paulo Brazil Institute of Chemistry Rio de Janeiro State University 20550-900 Rio de Janeiro Rio de Janeiro Brazil Institute of Chemistry Uniuersity of Campinas 13083-970 Campinas Silo Paulo Brazil Center of-Natural and Human Sciences Federal Uniuerty of ABC 09210-580 Santo Andre Sao Paulo Brazil

We report the application of a solid lanthanum-ceria-zinc catalyst in the catalytic regeneration of diesel particulate filters （DPF） in diesel engines. We synthesized a CeO2- ZnO-La2O3 （Ce-Zn-La） mixed oxide by a lactic acid-mediated sol-gel method, which efficiently coated cordierite substrates for soot capture and combustion. We studied the effects of La loading on the physicochemical and catalytic properties of Ce-Zn mixed oxide during lowtemperature soot combustion processes. We characterized the synthesized catalysts by X-ray diffraction （XRD）, Fourier-transform infrared spectroscopy （FTIR）, N2 adsorption, Raman spectroscopy, oxygen storage capacity （OSG）, and scanning and transmission electron microscopy （SEM and TEM）. Thermogravimetric and differential thermal analysis （TGA/DTA） confirmed that the catalysts effectively reduced the soot oxidation temperature. The ternary Ce-Zn-La mixed oxide catalyst with Ce/Zn/La atomic ratio of 2：1：0.5 had the highest catalytic activity and promoted soot oxidation at temperatures below 390℃. This indicated that the large number of oxygen vacancies in the catalyst structure generated oxygen species at low temperatures. Raman spectroscopy measurements revealed the presence of oxygen vacancies and lattice defects in Ce-Zn-La samples, which were key parameters concerning the stability and redox properties of the prepared catalysts.

关键词： soot combustion Ceria Ternary mixed oxide Cordierite coating Diesel particulate filter

Facile preparation and efficient MnxCoy porous nanosheets for the sustainable catalytic process of soot

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Green Energy & Environment 2024年第3期9卷 516-528页

作者： Miaomiao Hu Kun Zhou Tingyi Zhao Zheng Li Xianhai Zeng Di Yu Xuehua Yu Mingqin Zhao Zhihui Shao Qixiang Xu Bing Cui Flavors and Fragrance Engineering&Technology Research Center of Henan Province College of Tobacco ScienceHenan Agricultural UniversityZhengzhou450002China School of Ecology and Environment Zhengzhou UniversityZhengzhou450001China College of Energy Xiamen UniversityXiamen361102China College of Chemistry and Chemical Engineering Shenyang Normal UniversityShenyang110034China

The pursuit of high-performance is worth considerable effort in catalysis for energy efficiency and environmental sustainability. To develop redox catalysts with superior performance for soot combustion, a series of Mn_(x)Co_(y) oxides were synthesized using MgO template substitution.This method greatly improves the preparation and catalytic efficiency and is more in line with the current theme of green catalysts and sustainable development. The resulting Mn_(1)Co_(2.3) has a strong activation capability of gaseous oxygen due to a high concentration of Co^(3+) and Mn^(3+). The Mn doping enhanced the intrinsic activity by prompting oxygen vacancy formation and gaseous oxygen adsorption. The nanosheet morphology with abundant mesoporous significantly increased the solid–solid contact efficiency and improved the adsorption capability of gaseous reactants. The novel design of Mn_(1)Co_(2.3)oxide enhanced its catalytic performance through a synergistic effect of Mn doping and the porous nanosheet morphology, showing significant potential for the preparation of high-performance soot combustion catalysts.

关键词： soot combustion Intrinsic activity Contact efficiency Mn doping DFT

Effects of Zr substitution on soot combustion over cubic fluorite-structured nanoceria:soot-ceria contact and interfacial oxygen evolution

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Journal of Environmental Sciences 2021年第3期33卷 293-303页

作者： Peng Liu Xiaoliang Liang Yanliu Dang Junkai He Alireza Shirazi-Amin Laura A.Achola Shanka Dissanayake Hanlin Chen Mingli Fu Daiqi Ye Steven L.Suib School of Environment and Energy South China University of TechnologyGuangzhou 510006China CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Institute of Materials Science University of ConnecticutStorrsConnecticut 06269USA Department of Chemistry University of ConnecticutStorrsConnecticut 06269USA Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China University of Chinese Academy of Sciences Beijing 100049China

Ceria is widely used as a catalyst for soot combustion,but effects of Zr substitution on the reaction mechanism is ambiguous.The present work elucidates effects of Zr substitution on soot combustion over cubic fluorite-structured nanoceria.The nanostructured CeO_(2),Ce_(0.92)Zr_(0.08)O_(2),and Ce_(0.84)Zr_(0.16)O_(2)composed of 5-6 nm crystallites display T_(m-CO2)(the temperature at maximum CO_2 yield)at 383,355,and 375℃under 10 vol.%O_(2)/N_(2),respectively.The size of agglomerate decreases from 165.5 to 51.9-57.3 nm,which is beneficial for the sootceria contact.Moreover,Zr increases the amount of surface oxygen vacancies,generating more active oxygen(O_(2)^-and O^(-))for soot oxidation.Thus,the activities of Ce_(0.92)Zr_(0.08)O_(2)and Ce_(0.84)Zr_(0.16)O_(2)in soot combustion are better than that of CeO_(2).Although oxygen vacancies promote the migration of lattice O~(2-),the enriched surface Zr also inhibits the mobility of lattice O^(2-).Therefore,the T_(m-CO2)of Ce_(0.84)Zr_(0.1)6 O_(2)is higher than that of Ce_(0.92)Zr_(0.08)O_(2).Based on reaction kinetic study,soot in direct contact with ceria preferentially decomposes with low activation energy,while the oxidation of isolated soot occurs through diffusion with high activation energy.The obtained findings provide new understanding on the soot combustion over nanoceria.

关键词： Nanoceria soot combustion Zr substitution Oxygen mobility Reaction kinetic

Efficient low-temperature soot combustion by bimetallic Ag–Cu/SBA-15 catalysts

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Journal of Environmental Sciences 2018年第2期30卷 122-129页

作者： Zhaojun Wen Xinping Duan Menglin Hu Yanning Cao Linmin Ye Lilong Jiang Youzhu Yuan State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Laboratory for Green Chemical Productions of Alcohols-EthersEsters College of Chemistry and Chemical Engineering Xiamen University National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou University

In this study, the effects of copper（Cu） additive on the catalytic performance of Ag/SBA-15 in complete soot combustion were investigated. The soot combustion performance of bimetallic Ag–Cu/SBA-15 catalysts was higher than that of monometallic Ag and Cu catalysts. The optimum catalytic performance was acquired with the 5 Ag1-Cu0.1/SBA-15 catalyst, on which the soot combustion starts at Tig= 225°C with a T50= 285°C. The temperature for 50% of soot combustion was lower than that of conventional Ag-based catalysts to more than 50°C（Aneggi et al., 2009）. Physicochemical characterizations of the catalysts indicated that addition of Cu into Ag could form smaller bimetallic Ag–Cu nanolloy particles, downsizing the mean particle size from 3.7 nm in monometallic catalyst to 2.6 nm in bimetallic Ag–Cu catalyst. Further experiments revealed that Ag and Cu species elicited synergistic effects, subsequently increasing the content of surface active oxygen species. As a result, the structure modifications of Ag by the addition of Cu strongly intensified the catalytic performance.

关键词： Silver Copper Bimetallic catalyst Nanoalloy soot combustion Thermal stability

Structure and catalytic property of CeO_2-ZrO_2-Fe_2O_3 mixed oxide catalysts for diesel soot combustion: Effect of preparation method

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Journal of Rare Earths 2014年第9期32卷 817-823页

作者：顾振华桑秀丽王华李孔斋 Oxbridge College Kunming University of Science and Technology Quality Development Institute of Kunming University of Sci-ence and Technology Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction Ministry of Ed-ucation Kunming University of Science and Technology

A series of Ceo.sFeo.30Zr0.20O2 catalysts were prepared by different methods （co-precipitations method, citric acid sol-gel method, impregnation method, physical mixed method, and hydrotherrnal method） and characterized by X-ray diffraction （XRD）, Raman spectroscopy, Brunauer-Emmett-Teller （BET） and H2-TPR measurements. Potential of the catalysts in the soot oxidation was evaluated in a temperature-programmed oxidation （TPO） apparatus. The results showed that all the Fe3＋ and Zr4＋ were incor- porated into ceria lattice to form a pure Ce-Fe-Zr-O solid solution for the co-precipitation sample, but two kinds of Fe phases ex- isted in the Ce-Fe-Zr-O catalysts prepared by other methods： Fe3＋ incorporated into CeO2 lattice and dispersed Fe2O3 clusters. The free Fe2O3 clusters could improve the activity of catalysts for soot oxidation comparing with the pure Ce-Fe-Zr-O solid solution owing to the synergetic effect between free Fe2O3 and surface oxygen vacancies. In addition, the activity of catalysts strongly relied on the surface reducibility of free Fe2O3 particles. Holding both abundant free Fe2O3 particles and high oxygen vacancy concentration, the hydrothermal Ce0.5Fe0.3Zr0.202 catalyst presented the lowest Ti （251℃, ignition temperature of soot oxidation） and Tm （310 ℃, maximum oxidation rate temperature） for soot combustion （with tight-contact between soot and catalysts） among the five samples. Even after aging at 800 ℃ for 10 h, the Ti and Tm were still relatively low, at 273 and 361 ℃, respectively, indicating high catalytic stability.

关键词： Ce0.5Fe0.30Zr0.20O2 mixed oxides soot combustion solid solution interaction hydrothermal method rare earths

Catalytic combustion of soot over Ru-doped mixed oxides catalysts

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Journal of Rare Earths 2014年第7期32卷 610-620页

作者： L.F.Nascimento R.F.Martins O.A.Serra Department of Chemistry Faculdade de FilosofiaCiências e Letras de Ribeirao PretoUniversity of Sao PauloAv.Bandeirantes 3900CEP 14040-901 Ribeirao PretoSPBrazil

We employed modified substrates as outer heterogeneous catalysts to reduce the soot originating from the incomplete diesel combustion. Here, we proposed that ceria（CeO2）-based catalysts could lower the temperature at which soot combustion occurred from 610 oC to values included in the operation range of diesel exhausts（270–400 oC）. Here, we used the sol-gel method to synthesize catalysts based on mixed oxides（ZnO：CeO2） deposited on cordierite substrates, and modified by ruthenium nanoparticles. The presence of ZnO in these mixed oxides produced defects associated with oxygen vacancies, improving thermal stability, redox potential, sulfur resistance, and oxygen storage. We evaluated the morphological and structural properties of the material by X-ray diffraction（XRD）, Brumauer-emmett-teller method（BET）, temperature programmed reduction（H2-TPR）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. We investigated how the addition of Ru（0.5 wt.%） affected the catalytic activity of ZnO：CeO2 in terms of soot combustion. Thermogravimetric analysis（TG/DTA） revealed that presence of the catalyst decreased the soot combustion temperature by 250 oC, indicating that the oxygen species arose at low temperatures, which was the main reason for the high reactivity of the oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy（DRS） showed that the catalyst containing Ru on the mixed oxide-impregnated cordierite samples efficiently oxidized soot in a diesel stationary motor： soot emission decreased 80%.

关键词： soot combustion ceria mixed oxides ruthenium nanoparticles rare earths

Preparation of ultrafine Ce-based oxide nanoparticles and their catalytic performances for diesel soot combustion

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Journal of Rare Earths 2014年第2期32卷 124-130页

作者：韦岳长赵震焦金庆刘坚段爱军姜桂元 State Key Laboratory of Heavy Oil Processing China University of Petroleum

The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. The activities of the catalysts for soot oxidation were evaluated by the temperature-programmed oxidation （TPO） reaction. Ce-based oxides prepared in this study exhibited high catalytic activity for soot oxidation under tile condition of loose contact between soot particles and catalysts, and the catalytic ac- tivity ofultrafine Ce0.gZr0 iO2 nanoparticle for soot combustion was the highest, whose/＂10, Ts0 and Sco2m was 364, 442 ~C and 98.3%, respectively. All catalysts were systematically characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brumauer-Emett-Teller （BET）, Fourier transform infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS）. It was indicated that the MDC method could prepare the ultrafine Ce-bascd oxide nanoparticles whose the crystal lattice were perfect, and the BET surface area and average crystal size of the ultrafine nanoparticles changed with the different element dopings （Zr, Y）. The H2-TPR measurements showed that the ultrafine Ce-based ox- ide nanoparticles with the doping-Zr cation could be favorable for improving the redox property of the catalysts.

关键词： ultrafine nanoparticles Ce-based oxides catalysts soot combustion micropores-diffused coprecipitation rare earths

Promotional effects of cerium doping and NO_x on the catalytic soot combustion over MnMgAlO hydrotalcite-based mixed oxides

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Journal of Rare Earths 2014年第2期32卷 176-183页

作者：李倩王晓常伟陈慧张昭良 School of Chemistry and Chemical Engineering Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical MaterialsUniversity of Jinan

A series of MnMgA10 samples with different amounts of Ce doping were facilely prepared using coprecipitation method and their catalytic soot combustion activity was evaluated by temperature programmed oxidation reaction （TPO）. The methods of X-ray diffraction （XRD）, Brumauer-Emmett-Teller （BET）, H2-TPR, NO-TPO and in situ 1R were used to characterize the physio- chemical properties of these samples. Dopant Ce improved the soot combustion performance of MnMgA10 catalyst due to the en- hanced redox ability. Introduction of NOx led to the further increase of catalytic soot oxidation activity on these samples. Over Ce-containing samples, the catalytic activity was slightly decreased as the amount of dopant Ce increased in 02. Diftbrently, in NO＋O2, a certain amount of dopant Ce was much more favorable and excess amount of Ce resulted in a sharp drop of the catalytic soot combustion activity. Both NO： and nitrates were found to have great contributions to the effects of NOx on the soot combustion activity of Ce-doped catalysts. More NO2 was generated as dopant Ce increased. When appropriate amount of Ce was introduced, the as-formed NO2 was stored as bridging bidentate nitrate on Mn-Ce site, which was confirmed to have higher reactivity with soot than nitrite or monodentate nitrate on Mn and/or Ce sites. Overall, Mno.sMg2.sCeo.lAlo.90 was considered as the most potential catalyst for soot combustion.

关键词： hydrotalcite soot combustion NO2 bridging bidentate nitrate monodentate nitrate rare earths