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Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane
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作者 Tongtong Wu yuechang wei +5 位作者 Jing Xiong Yitao Yang Zhenpeng Wang Dawei Han Zhen Zhao Jian Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期331-344,共14页
It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(... It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application. 展开更多
关键词 3DOM catalysts Ca ions Sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species
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Three-dimensional ordered macroporous perovskite-type La_(1-x)K_xNiO_3 catalysts with enhanced catalytic activity for soot combustion: the Effect of K-substitution 被引量:8
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作者 Xuelei Mei Jing Xiong +4 位作者 yuechang wei Chujun Wang Qiangqiang Wu Zhen Zhao Jian Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第5期722-732,共11页
Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission elec... Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles. 展开更多
关键词 Three-dimensional ordered macroporous material LANIO3 Potassium Perovskite Soot combustion
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Synthesis of a new ordered mesoporous NiMoO_4 complex oxide and its efficient catalytic performance for oxidative dehydrogenation of propane 被引量:7
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作者 Xiaoqiang Fan Jianmei Li +4 位作者 Zhen Zhao yuechang wei Jian Liu Aijun Duan Guiyuan Jiang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第2期171-178,共8页
Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-... Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4 with the coexistence of a-NiMoO4 and fl-NiMoO4 showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoOa was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4 catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogena- tion of propane in comparison with bulk NiMoO4. 展开更多
关键词 ----w 7ordered mesoporous structure NiMoO4 complex oxide vacuum nanocasting PROPANE oxidative dehydrogenation
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Fabrication of ultrafine Pd nanoparticles on 3D ordered macroporous TiO_2 for enhanced catalytic activity during diesel soot combustion 被引量:4
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作者 yuechang wei Qiangqiang Wu +2 位作者 Jing Xiong Jian Liu Zhen Zhao 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期606-612,共7页
Nanocatalysts consisting of three‐dimensionally ordered macroporous(3DOM)TiO2‐supported ultrafine Pd nanoparticles(Pd/3DOM‐TiO2‐GBMR)were readily fabricated by gas bubbling‐assisted membrane reduction(GBMR)method... Nanocatalysts consisting of three‐dimensionally ordered macroporous(3DOM)TiO2‐supported ultrafine Pd nanoparticles(Pd/3DOM‐TiO2‐GBMR)were readily fabricated by gas bubbling‐assisted membrane reduction(GBMR)method.These catalysts had a well‐defined and highly ordered macroporous nanostructure with an average pore size of 280 nm.In addition,ultrafine hemispherical Pd nanoparticles(NPs)with a mean particle size of 1.1 nm were found to be well dispersed over the surface of the 3DOM‐TiO2 support and deposited on the inner walls of the material.The nanostructure of the 3DOM‐TiO2 support ensured efficient contact between soot particles and the catalyst.The large interface area between the ultrafine Pd NPs and the TiO2 also increased the density of sites for O2 activation as a result of the strong metal(Pd)‐support(TiO2)interaction(SMSI).A Pd/3DOM‐TiO2‐GBMR catalyst with ultrafine Pd NPs(1.1 nm)exhibited higher catalytic activity during diesel soot combustion compared with that obtained from a specimen having relatively large Pd NPs(5.0 nm).The T10,T50 and T90 values obtained from the former were 295,370 and 415°C.Both the activity and nanostructure of the Pd/3DOM‐TiO2‐GBMR catalyst were stable over five replicate soot oxidation trials.These results suggest that nanocatalysts having a 3DOM structure together with ultrafine Pd NPs can decrease the amount of Pd required,and that this approach has potential practical applications in the catalytic combustion of diesel soot particles. 展开更多
关键词 Ordered macroporous material Pd TiO2 Diesel soot combustion Ultrafine nanoparticle Heterogeneous catalysis
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Variable valence Mo^(5+)/Mo^(6+)ionic bridge in hollow spherical g-C_(3)N_(4)/Bi_(2)MoO_(6) catalysts for promoting selective visible light-driven CO_(2)photoreduction into CO 被引量:3
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作者 Wenjie He yuechang wei +8 位作者 Jing Xiong Zhiling Tang Yingli Wang Xiong Wang Hui Xu Xiao Zhang Xiaolin Yu Zhen Zhao Jian Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期361-372,I0009,共13页
Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ioni... Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion. 展开更多
关键词 g-C_(3)N_(4) Bi_(2)MoO_(6) Mo^(5+)/Mo^(6+)ionic bridge CO_(2)photoconversion CO production
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Three-dimensionally ordered macroporous CeO_2/Al_2O_3-supported Au nanoparticle catalysts: Effects of CeO_2 nanolayers on catalytic activity in soot oxidation 被引量:5
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作者 Baofang Jin yuechang wei +5 位作者 Zhen Zhao Jian Liu Yazhao Li Renjie Li Aijun Duan Guiyuan Jiang 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第9期1629-1641,共13页
A series of catalysts consisting of three‐dimensionally ordered macroporous(3DOM)x‐CeO2/Al2O3‐supported Au nanoparticles(x=2,10,20,and40wt%)were successfully synthesized using a reduction‐deposition method.These c... A series of catalysts consisting of three‐dimensionally ordered macroporous(3DOM)x‐CeO2/Al2O3‐supported Au nanoparticles(x=2,10,20,and40wt%)were successfully synthesized using a reduction‐deposition method.These catalysts were characterized using scanning electron microscopy,the Brunauer‐Emmett‐Teller method,X‐ray diffraction,transmission electron microscopy,ultraviolet‐visible spectroscopy,and temperature‐programmed reduction by H2.Au nanoparticles of mean particle size5nm were well dispersed and supported on the inner walls of uniform macropores.The3DOM structure improved the contact efficiency between soot and the catalyst.An Al‐Ce‐O solid solution was formed in the multilayer support,i.e.,x‐CeO2/Al2O3,by the incorporation of Al3+ions into the CeO2lattice,which resulted in the creation of extrinsic oxygen vacancies.Strong interactions between the metal(Au)and the support(Ce)increased the amount of active oxygen species,and this promoted soot oxidation.The catalytic performance in soot combustion was evaluated using a temperature‐programmed oxidation technique.The presence of CeO2nanolayers in the3DOM Au/x‐CeO2/Al2O3catalysts clearly improved the catalytic activities in soot oxidation.Among the prepared catalysts,3DOM Au/20%CeO2/Al2O3showed high catalytic activity and stability in diesel soot oxidation. 展开更多
关键词 Three‐dimensionally ordered macroporous material Gold nanoparticle Multilayer support CeO2 nanolayer Soot combustion
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Promoted catalytic performances of highly dispersed V-doped SBA-16 catalysts for oxidative dehydrogenation of ethane to ethylene 被引量:2
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作者 Lian Kong Jianmei Li +4 位作者 Qinglong Liu Zhen Zhao Qianyao Sun Jian Liu yuechang wei 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第4期577-586,共10页
V-doped SBA-16 catalysts (V-SBA-16) with 3D nanocage mesopores have been successfully synthesized by a modified one-pot method under weak acid condition. The obtained materials were characterized by means of small ang... V-doped SBA-16 catalysts (V-SBA-16) with 3D nanocage mesopores have been successfully synthesized by a modified one-pot method under weak acid condition. The obtained materials were characterized by means of small angle XRD, N2adsorption–desorption, TEM, UV–Vis and UV-Raman spectroscopy. These characterization results indicated that well-order mesoporous structures were maintained even at higher vanadium loadings and high concentration of VOxspecies were incorporated into the framework of SBA-16 support. The catalytic performances of V-SBA-16, V/SBA-16 and V/SiO2catalysts were comparatively investigated for the oxidative dehydrogenation of ethane to ethylene. The highest selectivity to ethylene of 63.3% and ethylene yield of 25.6% were obtained over 1.0V-SBA-16 catalyst. The superior catalytic performance of V-SBA-16 catalysts could be attributed to the presence of isolated framework VOxspecies, the unique structure of SBA-16 support and weak acidity. Moreover, V/SiO2catalyst exhibited relatively poor catalytic activity duo to the formation of V2O5nanoparticles on the surface of SiO2support and the low dispersion of VOxspecies. These results indicated that the catalytic performances of the studied catalysts were strongly dependent on the vanadium loading, the nature and neighboring environment of VOxspecies and the structure of support. © 2016 展开更多
关键词 Catalyst selectivity CATALYSTS DEHYDROGENATION ETHANE ETHYLENE VANADIUM
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Selective oxidation of ethane to aldehydes over SBA-15 supported molybdenum catalyst 被引量:1
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作者 Jianmei Li Jian Liu +7 位作者 Liwei Ren Qinglong Liu Zhen Zhao Yongsheng Chen Pengyu Zhu yuechang wei Aijun Duan Guiyuan Jiang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第5期609-616,共8页
SBA-15 supported Mo catalysts (Moy/SBA-15) were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsor... SBA-15 supported Mo catalysts (Moy/SBA-15) were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsorption-desorption, XRD, TEM, UV-Vis, Raman, XANES and H2-TPR. The results showed that a trace amount of MoO3 was produced on high Mo content samples. Tum-over frequency (TOF) and product selectivity are dependent on the molybdenum content. Both Mo0.75/SBA-15 and Mo1.75/SBA-15 catalysts give the higher catalytic activity and the selectivity to the total aldehydes for the selective oxidation of C2H6. At the reaction temperature of 625℃, the maximum yield of aldehydes reached 4.2% over Mo0.75/SBA-15 catalyst. The improvement of the activity and selectivity was related with the state of MoOx species. 展开更多
关键词 selective oxidation of ethane supported oxides catalysts Mo ALDEHYDES SBA-15
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Efficient Contact between H_(2)O and N-Coordinate Ru Nanoparticles in Three-Dimensionally Ordered Macro/Mesoporous Carbon Boosting Alkaline HER
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作者 Jiaqing Luo Chunyu Liu +9 位作者 Ruolin Zhang Yuanqing Sun Hua Xu Qingying Hu Manxue Zhang Jun Li Zhenxing Li weiyu Song yuechang wei Jian Liu 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第2期164-170,共7页
In this study,a novel approach is proposed to achieve the uniformly dispersed Ru nanoparticles with N coordination loaded on three-dimensionally ordered macro/mesoporous carbon(3DOMMC)through simultaneous pyrolysis of... In this study,a novel approach is proposed to achieve the uniformly dispersed Ru nanoparticles with N coordination loaded on three-dimensionally ordered macro/mesoporous carbon(3DOMMC)through simultaneous pyrolysis of Ru^(3+)and cyanamide on 33DOMMC.In an alkaline medium,the synthesized catalysts exhibit exceptional hydrogen evolution reaction(HER)performance.Specificall,Ru-N/3DOMMC demonstrates a significantly low overpotential of 13.8 mV to achieve acrent density of 10 mA.cmzandit exhibits a mass activity 17.5 times higher than that of commercial Pt/C.The outstanding performance could be attributed to the ultrahigh Ru dispersion and more efficient contact between active sites and reactant,which derived from the large specific surface area and interconnective three-dimensionally macro/mesopores of 3DOMMC. 展开更多
关键词 3DOMMC Hydrogen evolution reaction ELECTROCATALYSIS Solid-liquid contact Energy conversion
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Synthesis and catalytic performance of macroporous La1-xCexCoO3 perovskite oxide catalysts with high oxygen mobility for catalytic combustion of soot 被引量:13
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作者 Jiachen Sun Zhen Zhao +5 位作者 Yazhao Li Xuehua Yu Linlin Zhao Jianmei Li yuechang wei Jian Liu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第6期584-593,共10页
The disordered macroporous-mesoporous La1-xCexCoO3 catalysts were prepared by complexcombustion method with ethylene glycol as complexing agent at relatively low calcination temperature.The samples were characterized ... The disordered macroporous-mesoporous La1-xCexCoO3 catalysts were prepared by complexcombustion method with ethylene glycol as complexing agent at relatively low calcination temperature.The samples were characterized by means of X-ray diffraction,N2 adsorption-ndash;desorption,Xray photoelectron spectroscopy,transmission electron microscopy,hydrogen temperature-programmed reduction and soot temperature-programmed reduction,and so on.The results show that the use of complexing agent and relatively low calcination temperature increase the specific surface area of the catalyst and have abundant pore structure.The Ce ions introduced into lattice of LaCoO3 mainly exist in the form of tetravalent.At the same time,Ce ions enhance the redox performance of the catalyst and the mobility of active oxygen species,which enhances the catalytic activity of the catalyst for soot combustion.The results of activity test show that La0.9Ce0.1CoO3 catalyst exhibits the highest activity in the absence of NO and NO2,and its T10,T50 and T90 are 371,444,and 497℃,respectively.At the same time,a possible reaction mechanism is proposed in this study based on the turnover frequency(TOF) calculated by isothermal anaerobic titrations,XPS and XRD results. 展开更多
关键词 Macroporous structure La1-xCexCoO3 perovskite oxide Reaction mechanism Soot combustion Rare earths
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Research advances of rare earth catalysts for catalytic purification of vehicle exhausts-Commemorating the 100th anniversary of the birth of Academician Guangxian Xu 被引量:9
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作者 Lanyi Wang Xuehua Yu +2 位作者 yuechang wei Jian Liu Zhen Zhao 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第10期1151-1180,I0001,共31页
Nowadays,air pollution has become a prominent environmental problem and has attracted much attention.With the increase of vehicle retention quantity,the exhaust emissions have become the main sources of air pollution.... Nowadays,air pollution has become a prominent environmental problem and has attracted much attention.With the increase of vehicle retention quantity,the exhaust emissions have become the main sources of air pollution.To reduce pollution and hazards,vehicle exhaust emission regulations are becoming stricter and stricter,which puts forward higher requirements for purification of vehicle exhausts.At present,rare earths have been widely applied in vehicle exhaust purification because of their good catalytic performance,which is attributed to their unique 4 f electron layer structure occupied without full electrons,excellent oxygen storage/release capacity and redox ability.In this paper,the current status of rare earth catalysts and application of rare earth in different fuel vehicle exhaust catalysts,including three-way catalysts(TWCs)for gasoline vehicles,diesel exhaust catalysts for different pollutants(particulate matter(PM),NOx,CO and HC)and catalysts for new energy vehicles with different fuels,are summarized in detail.Meanwhile,the corresponding mechanisms and the role of rare earth in vehicle exhaust catalysts are also simultaneously described.Furthermore,the challenges and development directions of rare earth catalysts for the purification of vehicle exhausts are also proposed. 展开更多
关键词 Rare earth catalysts Catalytic purification Vehicle exhausts Research advances
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The Z-scheme g-C_(3)N_(4)/3DOM-WO_(3) photocatalysts with enhanced activity for CO_(2) photoreduction into CO 被引量:7
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作者 Zhiling Tang Chujun Wang +3 位作者 Wenjie He yuechang wei Zhen Zhao Jian Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第2期939-942,共4页
The catalytic performance of light-derived CO_(2)reduction with H_(2)O is strongly dependent on the sepa-ration efficiency of photogenerated carriers.Herein,the direct Z-scheme catalysts(g-C_(3)N_(4)/3DOM-WO_(3))of gr... The catalytic performance of light-derived CO_(2)reduction with H_(2)O is strongly dependent on the sepa-ration efficiency of photogenerated carriers.Herein,the direct Z-scheme catalysts(g-C_(3)N_(4)/3DOM-WO_(3))of graphitic carbon nitride(g-C_(3)N_(4))nanosheets decorated three-dimensional ordered macroporous WO_(3)(3DOM-WO_(3))were successfully fabricated by using the in-situ colloidal crystal template method.The slow light effect of 3DOM-WO_(3)photonic crystals expands the absorption of visible light and improves the uti-lization of light energy.The Z-scheme structure of g-C_(3)N_(4)/3DOM-WO_(3)catalysts is able to upgrade the separation efficiency of photogenerated electron-hole pairs.The g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst,whose formation rate of CO product is 48.7μmol g^(−1)h^(−1),exhibits the excellent catalytic activity for CO_(2)reduc-tion.The transfer pathway of stimulated electrons over the g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst is proposed and discussed.The present approach provides unique insights into the rational development of high-performance photochemical systems for efficient CO_(2)reduction into valuable carbon-containing chemicals and energy fuels. 展开更多
关键词 3DOM-WO_(3) g-C_(3)N_(4) Z-scheme heterojunction CO_(2)conversion Photocatalysis
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Confining shell-sandwiched Ag clusters in MnO_(2)-CeO_(2)hollow spheres to boost activity and stability of toluene combustion 被引量:6
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作者 Menglan Xiao Xueqin Yang +4 位作者 Yue Peng Yucong Guo yuechang wei Maofa Ge Xiaolin Yu 《Nano Research》 SCIE EI CSCD 2022年第8期7042-7051,共10页
Supported noble metal catalysts have the promising application in volatile organic compounds(VOCs)catalytic combustion but suffer from the deactivation due to noble metal sintering at high temperatures.Herein,we repor... Supported noble metal catalysts have the promising application in volatile organic compounds(VOCs)catalytic combustion but suffer from the deactivation due to noble metal sintering at high temperatures.Herein,we report the construction of shellsandwiched MnO_(2)-Ag-CeO_(2)hollow spheres with remarkable sintering resistance and high activity in toluene combustion.Ag clusters were sandwiched between outer MnO_(2)and inner CeO_(2)shell to enlarge and stabilize metal–support active interface.The unique hollow structure could alter the electronic states of catalysts sites and increase the adsorbed site of reactant molecules.Meanwhile,Mn–Ag–Ce multi-interfaces in MnO_(2)-Ag-CeO_(2)could facilitate the sustainable activation and the stable release of oxygen species via a tandem transfer.The oxygen species at Ag–Mn interface perimeter were instantly replenished by Ag–Ce interface to accelerate a deep oxidation of intermediates,guaranteeing the opening of benzene ring to generate maleic anhydride.This investigation provides a promising method for constructing efficient and sintering-resistant cluster catalysts for VOCs oxidation. 展开更多
关键词 hollow spheres multi-interfaces toluene combustion active lattice oxygen
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The selective catalytic reduction of NO over Ce_(0.3)TiO_x^-supported metal oxide catalysts 被引量:3
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作者 Zhichen Duan Jian Liu +5 位作者 Juan Shi Zhen Zhao yuechang wei Xiao Zhang Guiyuan Jiang Aijun Duan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第3期1-7,共7页
A Ce(0.3)TiOxoxide carrier was synthesized via a sol–gel process,and Ce(0.3)TiOxsupported metal(M=Cd,Mn,Fe,W,Mo)oxide catalysts were prepared by the method of incipient-wetness impregnation.The catalysts were c... A Ce(0.3)TiOxoxide carrier was synthesized via a sol–gel process,and Ce(0.3)TiOxsupported metal(M=Cd,Mn,Fe,W,Mo)oxide catalysts were prepared by the method of incipient-wetness impregnation.The catalysts were characterized by means of X-ray diffraction(XRD),Brunauer–Emmett–Teller(BET)analysis,scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier transform infrared(FT–IR)spectroscopy,UV–Visdiffusereflectancespectroscopy(UV–VisDRS),and Temperature-programmed reduction with H2(H2-TPR).The catalytic activities for de-NO(x )were evaluated by the NH3-SCR reaction.Among all the catalysts tested,the 2 wt.%Cd/Ce(0.3)TiOxcatalyst exhibited the best NH3-SCR performance,with a wide temperature window of 250–450℃ for NO conversion above 90%.Moreover,the catalyst showed N2 selectivity greater than 99%from 200 to 450℃. 展开更多
关键词 NOx NH3-SCR CATALYST SELECTIVITY Ce-Ti oxide
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Z-scheme heterojunction of SnS_(2)-decorated 3DOM-SrTiO_(3) for selectively photocatalytic CO_(2) reduction into CH4 被引量:3
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作者 Wenjie He Xingxing Wu +6 位作者 Yifei Li Jing Xiong Zhiling Tang yuechang wei Zhen Zhao Xiao Zhang Jian Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第10期2774-2778,共5页
The rapid recombination of photoinduced electron-hole pairs as well as the deficiency of high-energy carriers restricted the redox ability and products selectivity.Herein,the heterojunction of SnS_(2)-deco rated three... The rapid recombination of photoinduced electron-hole pairs as well as the deficiency of high-energy carriers restricted the redox ability and products selectivity.Herein,the heterojunction of SnS_(2)-deco rated three-dimensional ordered macropores(3DOM)-SrTiO_(3) catalysts were in-situ constructed to provide transmit channel for high-energy electron transmission.The suitable band edges of SnS_(2) and SrTiO_(3) contribute to the Z-scheme transfer of photogenerated carrier.The 3DOM structure of SrTiO_(3)-based catalyst possesses the slow light effect for enhancing light adsorption efficiency,and the surface alkalis strontium is benefit to the boosting adsorption for CO_(2).The in-situ introduced SnS_(2) decorated on the macroporous wall surface of 3DOM-SrTiO_(3) altered the primary product from CO to CH4.The Z-scheme electron transfer from SnS_(2) combining with the holes in SrTiO_(3) occurred under full spectrum photoexcitation,which improved the excitation and utilization of photogene rated electrons for C02 multi-electrons reduction.As a result,(SnS_(2))3/3 DOM-SrTiO_(3) catalyst exhibits higher activity for photocatalytic CO_(2) reduction to CH4 compared with single SnS_(2) or 3 DOM-SrTiO_(3),i.e.,its yield and selectivity of CH4 are 12.5μmol g^(-1) h^(-1) and 74.9%,re spectively.The present work proposed the theoretical foundation of Z-scheme heterojunction construction for enhancing photocatalytic activity and selectivity for CO_(2) conversion. 展开更多
关键词 3DOM-SrTiO3 SnS_(2) Z-scheme heterojunction CO_(2)conversion CH4 selectivity
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Fabrication of La1-xCaxFeO3 perovskite-type oxides with macro-mesoporous structure via a dual-template method for highly efficient soot combustion 被引量:2
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作者 Minjie Zhao Jixing Liu +4 位作者 Jian Liu Junfeng Xu Zhen Zhao yuechang wei weiyu Song 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第4期369-375,共7页
A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij... A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems. 展开更多
关键词 Three-dimensionally ordered macro-mesoporous structure PEROVSKITE-TYPE oxides LANTHANUM ferrite SOOT combustion Rare earths
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NH_3-SCR denitration catalyst performance over vanadium–titanium with the addition of Ce and Sb 被引量:19
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作者 Chi Xu Jian Liu +5 位作者 Zhen Zhao Fei Yu Kai Cheng yuechang wei Aijun Duan Guiyuan Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第5期74-80,共7页
Selective catalytic reduction technology using NH3 as a reducing agent(NH3-SCR) is an effective control method to remove nitrogen oxides. TiO2-supported vanadium oxide catalysts with different levels of Ce and Sb mo... Selective catalytic reduction technology using NH3 as a reducing agent(NH3-SCR) is an effective control method to remove nitrogen oxides. TiO2-supported vanadium oxide catalysts with different levels of Ce and Sb modification were prepared by an impregnation method and were characterized by X-ray diffractometer(XRD), Brunauer-Emmett-Teller(BET), Transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR), UV-Vis diffuse reflectance spectroscopy(UV-Vis DRS), Raman and Hydrogen temperature-programmed reduction(H2-TPR). The catalytic activities of V5 CexS by/TiO2 catalysts for denitration were investigated in a fixed bed flow microreactor. The results showed that cerium, vanadium and antimony oxide as the active components were well dispersed on TiO2, and the catalysts exhibited a large number of d-d electronic transitions, which were helpful to strengthen SCR reactivity. The V5 CexS by/TiO2 catalysts exhibited a good low temperature NH3-SCR catalytic activity. In the temperature range of 210 to 400℃, the V5 CexS by/TiO2 catalysts gave NO conversion rates above 90%. For the best V5Ce35Sb2/TiO2 catalyst, at a reaction temperature of 210℃, the NO conversion rate had already reached 90%. The catalysts had different catalytic activity with different Ce loadings. With the increase of Ce loading, the NO conversion rate also increased. 展开更多
关键词 VCeSb/TiO2 catalyst SCR Denitration Low temperature N2 selectivity
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Effect of Ce doping of TiO_2 support on NH_3-SCR activity over V_2O_5–WO_3/CeO_2–TiO_2 catalyst 被引量:18
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作者 Kai Cheng Jian Liu +5 位作者 Tao Zhang Jianmei Li Zhen Zhao yuechang wei Guiyuan Jiang Aijun Duan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第10期2106-2113,共8页
CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction(SCR) of NOx with NH3 were p... CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction(SCR) of NOx with NH3 were prepared by an incipient-wetness impregnation method. These catalysts were characterized by means of BET, XRD, UV–Vis,Raman and XPS techniques. The results showed that the catalytic activity of V2O5–WO3/TiO2 was greatly enhanced by Ce doping(molar ratio of Ce/Ti = 1/10) in the TiO2 support.The catalysts that were predominantly anatase TiO2 showed better catalytic performance than the catalysts that were predominantly fluorite CeO2. The Ce additive could enhance the surface adsorbed oxygen and accelerate the SCR reaction. The effects of O2 concentration, ratio of NH3/NO, space velocity and SO2 on the catalytic activity were also investigated. The presence of oxygen played an important role in NO reduction. The optimal ratio of NH3/NO was 1/1 and the catalyst had good resistance to SO2 poisoning. 展开更多
关键词 CeO2–TiO2 SCR Nitrogen oxides Homogeneous precipitation method SO2poisoning
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Synthesis and kinetics investigation of meso-microporous Cu-SAPO-34 catalysts for the selective catalytic reduction of NO with ammonia 被引量:8
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作者 Jixing Liu Fuhong Yu +4 位作者 Jian Liu Lifeng Cui Zhen Zhao yuechang wei Qianyao Sun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第10期45-58,共14页
A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH3-SCR performance at low temperature. Their s... A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH3-SCR performance at low temperature. Their structure and physic chemical properties were characterized by means of X-ray diffraction patterns (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N2 sorption-desorption, nuclear magnetic resonance (NMR), Inductively Coupled Plasma-Atomic Emission spectrometer (ICP-AES), X-ray absorption spectroscopy (XPS), Temperature-programmed desorption of ammonia (NH3-TPD), Ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS) and Temperature programmed reduction (TPR). The analysis results indicate that the high activities of Cu-SAPO-34 catalysts could be attributed to the enhancement of redox property, the formation of mesopores and the more acid sites. Furthermore, the kinetic results verify that the formation of mesopores remarkably reduces diffusion resistance and then improves the accessibility of reactants to catalytically active sites. The 1.0-Cu-SAPO-34 catalyst exhibited the high NO conversion (〉90%) among the wide activity temperature window in the range of 150- 425℃. 展开更多
关键词 Cu-SAPO-34 NOx KineticDiffusion resistanceSelective catalytic reduction
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Ordered macroporous structured TiO_(2)-based photocatalysts for CO_(2)reduction:A review 被引量:1
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作者 Yifei Li yuechang wei +3 位作者 Wenjie He Zhiling Tang Jing Xiong Zhen Zhao 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第12期53-64,共12页
Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation ef... Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation eficiency,solar energy utilization and CO_(2)adsorption rate during the conversion of CO_(2)to H_(2)O,we summarized five modification measures:including doping ions into OM TiO_(2),introducing sec-ond semiconductor coupling and noble metal nanoparticles for fabricating multiple Z-scheme heterojunc-tions,constructing hierarchical pore and carbon-loaded OM TiO_(2)materials,which effectively enhance the absorption rate of visible light,the separation rate of electrons-hole pairs and the selection of multiple active sites.The OM structured TiO_(2)-based photocatalysts solve the single or multiple key factors for en-hancing photocatalytic performances during CO_(2)conversion.The catalytic mechanism and pathways of OM structured TiO_(2)-based photocatalysts for CO_(2)reduction are discussed and summarized.It provides new insights on the development of high-efficient catalyst for photocatalytic CO_(2)conversion to solar fu-els. 展开更多
关键词 TiO_(2)-based materials Hierarchical pore CO_(2)reduction PHOTOCATALYSTS Solar fuels
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