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Journal of Rare Earths 2023年第6期41卷 917-925,I0004页

作者： Zhilin Fang Shuwen zhang Aiyong Wang Yanglong Guo Yun Guo Li Wang Wangcheng Zhan Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China International Joint Laboratory of Catalytic Chemistry Department of ChemistryResearch Center of Nano Science and TechnologyCollege of SciencesShanghai UniversityShanghai 200444China

Various Er modified MnO_(x) catalysts were synthesized using co-precipitation approach and tested in the selective catalytic reduction of NO_(x) by ammonia(NH_(3)-SCR).Catalysts were analyzed with various characterization techniques,and it is found that the doping of Er can enormously enhance the catalytic performance of MnO_(x)catalyst.MnEr_(0.1)demonstrates advantageous catalytic performance in the NH_(3)-SCR reaction owing to rich surface acidic sites,high surface content of Mn^(4+),superior redox capacity,and enhanced surface-adsorbed oxygen.From diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis,it is suggested that the MnEr0.1catalyst follows mainly Eley-Rideal mechanism while MnO_(x) is dominated by Langmuir-Hinshelwood mechanism.

关键词： Mn-based catalyst Selective catalytic reduction Rare earths Co-precipitation

Sm-MnO_(x)catalysts for low-temperature selective catalytic reduction of NO_(x)with NH_(3):Effect of precipitation agent

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Journal of Rare Earths 2022年第8期40卷 1199-1210页

作者： Junbin Ding Xinwei Yang Aiyong Wang Can Yang Yanglong Guo Yun Guo Li Wang Wangcheng Zhan Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis School of Chemistry&Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Hudong Heavy Machinery Co. Ltd.Shanghai 200237China International Joint Laboratory of Catalytic Chemistry Department of ChemistryResearch Center of Nano Science and TechnologyCollege of SciencesShanghai UniversityShanghai 200444China State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China

A series of Sm-Mn mixed oxide catalysts were prepared via precipitation using various precipitants,namely Na_(2)CO_(3)(NH_(4))_(2)CO_(3),and NH_(3)·H_(2)O,and evaluated for the selective catalytic reduction(SCR)of NO_(x)with NH_(3)at low temperatures.Various characterisation techniques were used to determine the physicochemical properties of the catalysts,and it is found that their catalytic performance is greatly influenced by the nature of the precipitation agent used.It is found that Sm_(0.1)Mn-Na_(2)CO_(3)and Sm_(0.1)Mn-(NH_(4))_(2)CO_(3)exhibit superior catalytic performance in the SCR reaction to that of Sm_(0.1)Mn-NH_(3)·H_(2)O due to an abundance of surface acid sites,high surface concentration of Mn^(4+),and high NO oxidation capacity.From in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFT)analysis,we conclude that the Sm-Mn catalysts follow both Eley-Rideal and Langmuir-Hinshelwood mechanisms,and that the Eley-Rideal mechanism is dominant at elevated temperatures.

关键词： Effect of precipitant Mn-based catalyst Selective catalytic reduction Rare earths

Effect of hydration on the surface basicity and catalytic activity of Mg-rare earth mixed oxides for aldol condensation

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Journal of Rare Earths 2018年第4期36卷 359-366页

作者： Zheng Wang Pascal Fongarland Guanzhong Lu Wangcheng Zhan Nadine Essayem Key Laboratory for Advanced Materials and REsearch Institute of Industrial Catalysis School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Institut de REcherches sur la Catalyse et l'Environnement de Lyon(IRCELYON) CNRS-Universite Lyon 12 Avenue Albert Einstein69626 Villeurbanne CedexFrance

Magnesium and rare earth mixed oxides（Mg3 REOx（RE=La, Y. Ce）） were prepared and characterized by Xray diffraction（XRD）, N_2 adsorption-desorption, infrared spectra and microcalorimetry of CO_2. The results reveal that the Mg_3 CeO_x catalyst is present in the form of Mg-Ce-O solid solution,while the Mg3 LaOx and Mg_3 YO_x catalysts are probably rare earth oxides dispersed on MgO surface. As a result, among the calcined Mg_3 REO_x catalysts, the Mg_3 CeO_x catalyst presents the highest rate constant for acetone aldolization, which is well correlated to its more homogeneous distribution of basic sites. In contrary, the Mg_3 YO_x catalyst exhibit the lowest catalytic activity for acetone aldolization. Upon hydration pre-treatment, the basic properties on the surface of the Mg_3 REO_x catalysts were changed markedly. The Mg_3 YO_x catalyst after hydration treatment shows the highest amount of basic sites on catalyst surface, and then exhibits the highest activity among the hydrated Mg_3 REO_x catalysts. These results make it possible to fine-tune basic sites for acetone aldolization.

关键词： Mg-rare earth mixed oxide Hydration treatment Water tolerance Aldol condensation Solid base catalyst Rare earths

Understanding the role of tungsten on Pt/CeO_(2)for vinyl chloride catalytic combustion

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Journal of Rare Earths 2022年第9期40卷 1462-1470,I0005页

作者： Qifeng zhang Zhengbo Zhou Tian Fang Han Gu Yanglong Guo Wangcheng Zhan Yun Guo Li Wang Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis School of Chemistry&Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Spherical CeO_(2)synthesized by the hydrothermal process was used as support to prepare Pt/WO_(3)/CeO_(2),and the effects of tungsten(W)contents on activity,stability and polychlorinated by-products were investigated to understand the role of W for vinyl chloride(VC)catalytic oxidation.The introduction of12 wt%W to Pt/CeO_(2)(P12 WC)exhibits the highest catalytic activity with 90%conversion of VC at 250℃,meanwhile the stability improves and the polychlorinated by-products in the tail gas significantly decrease due to the removal of dissociated Cl species in the formation of HCl.The beneficial effects of W on Pt/CeO_(2)are closely related to the chemical state of Pt,redox and surface acid sites distribution.The doped W not only makes Pt disperse evenly on the support with the high valence,but also weakens the interaction between Pt and CeO_(2)by the formation of Pt-O-W and Pt-O-W-O-Ce species,which facilitates oxygen mobility.In addition,the modification of W species also significantly increases the surface acidity amount and changes the distribution of acid sites.

关键词： Tungsten oxides Vinyl chloride Catalytic oxidation Pt/CeO_(2) By-products Rare earths

Low-temperature catalytic combustion of trichloroethylene over MnO_(x)-CeO_(2)mixed oxide catalysts

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稀土学报：英文版 2023年第4期41卷 523-530页

作者： Kai Shen Mingxiang Jiang Xinwei Yang Weizhong Zhou Qiguang Dai Xingyi Wang Li Wang Yun Guo Yanglong Guo Wangcheng Zhan Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Hudong Heavy Machinery Co. Ltd.Shanghai 200237China

The cerium-based catalysts were investigated for the catalytic co mbustion of trichlo roethylene(TCE)and exhibit a surprising catalytic activity.MnO_(x)was doped into CeO_(2)by a citric acid(CA)sol-gel method,and the effect of Mn content on the physicochemical properties and catalytic activities of MnO_(x)-CeO_(2)mixed oxides was investigated systemically.The introduction of MnO_(x)into CeO_(2)can evidently improve the catalytic activity and reaction stability of the CeO_(2)catalyst,and the catalytic activity can be maintained for more than 100 h at 250℃under air atmosphere.Moreover,a possible reaction mechanism and a catalytic cycle for the catalytic combustion of TCE over the MnO_(x)-CeO_(2)mixed oxide catalysts are proposed.

关键词： Catalytic combustion Trichloroethylene Cerium oxide Manganese oxide Rare Earths

Catalytic wet oxidation of N,N-dimethyl formamide over ruthenium supported on CeO_2 and Ce_(0.7)Zr_(0.3)O_2 catalysts

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Journal of Rare Earths 2019年第3期37卷 265-272页

作者： Jiawen Gong Dongzhi Li Li Wang Wangcheng Zhan Yanglong Guo Yunsong Wang Yun Guo Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis School of Chemistry & Molecular Engineering East China University of Science and Technology

A series of Ru supported on CeO_2 and Ce_(0.7)Zr_(0.3)O_2(CeZrO) was prepared by incipient-wet impregnation method and investigated in the catalytic wet oxidation of N,N-dimethyl formamide(DMF) in batch reactor. The physicochemical property of the catalysts was characterized by Brunauer-Emmett-Teller(BET), X-ray diffraction(XRD), H_2 temperature-programmed reduction(H_2-TPR), X-ray photoelectron spectroscopy(XPS) and thermogravimetry(TG). Compared with 3%Ru/CeO_2, 3%Ru/Ce_(0.7)Zr_(0.3)O_2 catalyst exhibits much higher performance for DMF degradation due to the promotion of Ru dispersion and the transfer of active oxygen, and 99% DMF conversion and 97% COD elimination are obtained at 453 K,2.5 MPa oxygen pressure after 5 h. The reaction mechanism of DMF degradation was suggested. The carbonaceous species deposition and oxidation of Ru can be responsible for catalyst deactivation. And the catalyst activity can be recovered by air calcination and H_2 reduction.

关键词： Catalytic wet oxidation N,N-dimethyl formamide Ru Degradation Catalyst deactivation and regeneration Rare earths

Al2O3 supported hybrid Pd-CeO2 colloidal spheres and its enhanced catalytic performances for methane combustion

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Journal of Rare Earths 2019年第7期37卷 714-719页

作者： Xinwei Yang Chenhao Du Yanglong Guo Yun Guo Li Wang Yunsong Wang Wangcheng Zhan Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Sinopec Shanghai Research Institute of Petrochemical Technology Shanghai 201208China

Fabrication of novel nano-catalyst with improved activity and stability has been a hot topic in heterogeneous catalysis. Herein a novel approach was designed to synthesize Pd-CeO2 colloidal assembled spheres(CASs) in one-pot fashion. The Pd clusters were encompassed by the CeO2 nanocrystals with a high dispersity. Based on this hybrid structure, the Pd/ceria interface area can be greatly improved. After Pd-CeO2 CASs was supported on γ-Al2O3, its catalytic activity for CH4 combustion was evaluated. The result shows that Al2O3 supported Pd-CeO2 CASs exhibits an improved catalytic activity and stability,compared to the Pd/CeO2 catalyst prepared by impregnation method. The results of several characterization techniques indicate that the enhanced catalytic activity of Al2O3 supported Pd-CeO2 CASs can be attributed to the more interfacial Pd-O-Ce species and the more surface active oxygen species.

关键词： CeO2 Interface area Methane combustion Stability Rare earths

Highly efficient cobalt-doped carbon nitride polymers for solvent-free selective oxidation of cyclohexane

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Green Energy & Environment 2017年第2期2卷 142-150页

作者： Yu Fu Wangcheng Zhan Yanglong Guo Yun Guo Yunsong Wang Guanzhong Lu Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis School of Chemistry and Molecular Engineering East China University of Science and Technology

Selective oxidation of saturated hydrocarbons with molecular oxygen has been of great interest in catalysis, and the development of highly efficient catalysts for this process is a crucial challenge. A new kind of heterogeneous catalyst, cobalt-doped carbon nitride polymer(g-C_3N_4),was harnessed for the selective oxidation of cyclohexane. X-ray diffraction, Fourier transform infrared spectra and high resolution transmission electron microscope revealed that Co species were highly dispersed in g-C_3N_4 matrix and the characteristic structure of polymeric g-C_3N_4 can be retained after Co-doping, although Co-doping caused the incomplete polymerization to some extent. Ultraviolet-visible, Raman and X-ray photoelectron spectroscopy further proved the successful Co doping in g-C_3N_4 matrix as the form of Co(Ⅱ)-N bonds. For the selective oxidation of cyclohexane, Co-doping can markedly promote the catalytic performance of g-C_3N_4 catalyst due to the synergistic effect of Co species and gC_3N_4 hybrid. Furthermore, the content of Co largely affected the activity of Co-doped g-C_3N_4 catalysts, among which the catalyst with 9.0 wt%Co content exhibited the highest yield(9.0%) of cyclohexanone and cyclohexanol, as well as a high stability. Meanwhile, the reaction mechanism over Co-doped g-C_3N_4 catalysts was elaborated.

关键词： Selective oxidation of cyclohexane Oxygen oxidant Carbon nitride Co-doping

Effects of water on CO catalytic oxidation over Pd/CeO2

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Journal of Rare Earths 2020年第8期38卷 891-898,I0003页

作者： Shaofei Song Cheng zhang Yake Lou Yujin Wu Li Wang Yanglong Guo Wangcheng Zhan Yun Guo Key Lab for Advanced Material Laboratory for Research Institute of Industrial CatalysisSchool of Chemistry&Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

The role of water in CO oxidation was investigated on Pd/CeO2 with different morphologies(rods(R),cubes(C)and octahedrons(O)).Compared with the absence of water,CO oxidation activity increases 2 times in the presence of water on Pd/CeO2-C;but a decrease is found on Pd/CeO2-R.Catalyst characterization reveals that Pd is mainly in the form of solid solution(PdxCe1-xO2-σ)on Pd/CeO2-R and a mixture of metal and PdxCe1-xO2-σsolid solution on Pd/CeO2-C.The strong interaction between Pd and CeO2-R results in the form of stable bidentate carbonates species;while the relatively weak interaction between Pd and CeO2-C leads to the produce of unstable monodentate carbonates species.The effects of water on CO oxidation activity closely relate with the Pd chemical state and the types of carbonates species.Water restrains CO adsorption on PdxCe1-xO2-σsolid solution,but it has negligent effects on metallic Pd species.In the presence of water,bidentate carbonates species remains stable but the decrease in the amount of monodentate carbonates species is observed.

关键词： CO oxidation Pd catalyst Support morphology Water Rare earths

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回馈服务对中青年志愿服务意愿的影响分析

社会治理 2021年第5期 37-45页

作者：张网成战立金北京师范大学中国社会管理研究院/社会学院北京师范大学社会学院

根据在北京市房山区实施的青年志愿服务调查,绝大多数中青年对获得他人的志愿服务都有潜在需要;在获得回馈服务的假设前提下,几乎所有中青年都愿意提供志愿服务;如果仅给中青年志愿者提供回馈服务,而不给其家人提供,那么中青年的志愿服... 详细信息

根据在北京市房山区实施的青年志愿服务调查,绝大多数中青年对获得他人的志愿服务都有潜在需要;在获得回馈服务的假设前提下,几乎所有中青年都愿意提供志愿服务;如果仅给中青年志愿者提供回馈服务,而不给其家人提供,那么中青年的志愿服务意愿会大幅下降;家庭生活困难对中青年志愿服务意愿有显著影响。本文建议:建立以家庭为单位的志愿者回馈服务激励制度,推动志愿服务组织能力建设,回馈服务要充分考虑中青年志愿者家庭面临的实际问题。

关键词：志愿服务意愿志愿服务需要回馈服务