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Fe- and Co-doped lanthanum oxides catalysts for ammonia decomposition:Structure and catalytic performances 被引量:7
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作者 XUN Yanran HE Xinxin +3 位作者 YAN Han GAO Ziwang JIN Zhao JIA Chunjiang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2017年第1期15-23,共9页
In this paper, a series of Fe- and Co-doped lanthanum(hydr)oxides catalysts were prepared by a simple coprecipitationhydrothermal method. The as-prepared catalysts were characterized with various techniques includin... In this paper, a series of Fe- and Co-doped lanthanum(hydr)oxides catalysts were prepared by a simple coprecipitationhydrothermal method. The as-prepared catalysts were characterized with various techniques including powder X-ray diffraction(XRD), N2 adsorption/desorption, inductively coupled plasma(ICP) and transmission electron microscopy(TEM). The Fe-based catalysts exhibited consecutive phase changes of amorphous Fe Ox→FeLaO3→Fe2N under different stages(as-prepared→calcination→ammonia decomposition reaction); as for Co-based catalysts, the phase transformation followed a sequence of Co(OH)2→Co3O4→metallic Co. It was revealed that Fe2N and metallic Co were most probably the active crystalline phase respectively for Feand Co-based catalysts in the decomposition of ammonia. 展开更多
关键词 transitional metal rare earth lanthanum(hydr)oxides composite catalysts ammonia decomposition
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Peroxymonosulfate Activation by CoFe_(2)O_(4)/MgAl-LDH Catalyst for the Boosted Degradation of Antibiotic
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作者 LI Jianjun CHEN Fangming +5 位作者 ZHANG Lili WANG Lei ZHANG Liting CHEN Huiwen XUE Changguo XU Liangji 《无机材料学报》 北大核心 2025年第4期440-448,I0022-I0024,共12页
Owing to outstanding hydrophilicity and ionic interaction,layered double hydroxides(LDHs)have emerged as a promising carrier for high performance catalysts.However,the synthesis of new specialized catalytic LDHs for d... Owing to outstanding hydrophilicity and ionic interaction,layered double hydroxides(LDHs)have emerged as a promising carrier for high performance catalysts.However,the synthesis of new specialized catalytic LDHs for degradation of antibiotics still faces some challenges.In this study,a CoFe_(2)O_(4)/MgAl-LDH composite catalyst was synthesized using a hydrothermal coprecipitation method.Comprehensive characterization reveals that the surface of MgAl-LDH is covered with nanometer CoFe_(2)O_(4) particles.The specific surface area of CoFe_(2)O_(4)/MgAl-LDH is 82.84 m^(2)·g^(-)1,which is 2.34 times that of CoFe_(2)O_(4).CoFe_(2)O_(4)/MgAl-LDH has a saturation magnetic strength of 22.24 A·m^(2)·kg^(-1) facilitating efficient solid-liquid separation.The composite catalyst was employed to activate peroxymonosulfate(PMS)for the efficient degradation of tetracycline hydrochloride(TCH).It is found that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH significantly exceeds that of CoFe_(2)O_(4).The maximum TCH removal reaches 98.2%under the optimal conditions([TCH]=25 mg/L,[PMS]=1.5 mmol/L,CoFe_(2)O_(4)/MgAl-LDH=0.20 g/L,pH 7,and T=25℃).Coexisting ions in the solution,such as SO_(4)^(2-),Cl-,H_(2)PO_(4)^(-),and CO_(3)^(2-),have a negligible effect on catalytic performance.Cyclic tests demonstrate that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH remains 67.2%after five cycles.Mechanism investigations suggest that O_(2)^(•-)and ^(1)O_(2) produced by CoFe_(2)O_(4)/MgAl-LDH play a critical role in the catalytic degradation. 展开更多
关键词 magnetic composite catalyst PEROXYMONOSULFATE CoFe_(2)O_(4)/MgAl-LDH advanced oxidation process antibiotic
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Photo-assisted electrocatalysis with bimetallic PdCu/TiO_(x)catalysts:Enhancing denitrification and economic viability
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作者 Yuxin Zeng Yan Luo +4 位作者 Yao He Kaihang Zhang Binbin Zhu Yuanzheng Zhang Junfeng Niu 《Chinese Chemical Letters》 2025年第6期618-624,共7页
Electrocatalysis for nitrate(NO_(3^(–)))removal from wastewater faces the challenge of merging efficient reduction and high selectivity to nitrogen(N2)with economic viability in a durable catalyst.In this study,bimet... Electrocatalysis for nitrate(NO_(3^(–)))removal from wastewater faces the challenge of merging efficient reduction and high selectivity to nitrogen(N2)with economic viability in a durable catalyst.In this study,bimetallic PdCu/TiO_(x)composite catalysts were synthesized with varying Pd and Cu ratios through electrochemical deposition on defective TiOxnanotube arrays.Denitrification experiments demonstrated that the Pd_(1)Cu_(1)/TiO_(x)catalyst exhibited the highest(NO_(3^(–)))removal rate(81.2%)and N_(2)selectivity(67.2%)among all tested catalysts.Leveraging the exceptional light-responsive property of TiO_(x),the introduction of light energy as an assisting factor in electrocatalysis further augmented the(NO_(3^(–)))treatment rate,resulting in a higher(NO_(3^(–)))removal rate of 95.1%and N_(2)selectivity of approximately 90%.Compared to individual electrocatalysis and photocatalysis systems,the overpotential for the catalytic interface active*H formation in the photo-assisted electrocatalysis system was remarkably reduced,thus accelerating electron migration and promoting(NO_(3^(–)))reduction kinetics.Economic analysis revealed an energy consumption of 2.74 k Wh/mol and a corresponding energy consumption per order(EEO)of 0.79 k Wh/m^(3)for the Pd_(1)Cu_(1)/TiOxcatalyst to reduce 25.2 mg/L of(NO_(3^(–)))-N in water to N_(2),showcasing remarkable competitiveness and economic advantages over other water treatment technologies.This study developed the PdCu/TiOxelectrocatalysts with high(NO_(3^(–)))removal rates and N_(2)selectivity,particularly when combined with light energy,the efficiency and selectivity were significantly enhanced,offering a competitive and economically viable solution for wastewater treatment. 展开更多
关键词 Nitrate reduction Photo-assisted electrocatalysis PdCu TiOx composite catalyst Nitrogen selectivity Economic analysis
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Synergistic Carbon Support Engineering in Composite Catalyst Layer for High-Performance PEM Fuel Cells
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作者 Siming Li Suizhu Pei +8 位作者 Enyang Sun Zhichao Liu Jieyu Zhang Junjie Li Huili Chen Haiwei Liang Zhonghua Xiang Min Wang Yawei Li 《Carbon Energy》 2025年第12期71-82,共12页
This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mas... This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications. 展开更多
关键词 composite catalyst layer ionomer distribution oxygen transport platinum utilization proton conduction
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α-MnO_2 nanoneedle-based hollow microspheres coated with Pd nanoparticles as a novel catalyst for rechargeable lithium-air batteries 被引量:3
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作者 张明 徐强 +3 位作者 桑林 丁飞 刘兴江 焦丽芳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第1期164-170,共7页
The hollow α-MnO2 nanoneedle-based microspheres coated with Pd nanoparticles were reported as a novel catalyst for rechargeable lithium-air batteries. The hollow microspheres are composed ofα-MnO2 nanoneedles. Pd na... The hollow α-MnO2 nanoneedle-based microspheres coated with Pd nanoparticles were reported as a novel catalyst for rechargeable lithium-air batteries. The hollow microspheres are composed ofα-MnO2 nanoneedles. Pd nanoparticles are deposited on the hollow microspheres through an aqueous-solution reduction of PdCl2 with NaBH4 at room temperature. The results of TEM, XRD, and EDS show that the Pd nanoparticles are coated on the surface ofα-MnO2 nanoneedles uniformly and the mass fraction of Pd in the Pd-coated α-MnO2 catalyst is about 8.88%. Compared with the counterpart of the hollow α-MnO2 catalyst, the hollow Pd-coated α-MnO2 catalyst improves the energy conversion efficiency and the charge-discharge cycling performance of the air electrode. The initial specific discharge capacity of an air electrode composed of Super P carbon and the as-prepared Pd-coatedα-MnO2 catalyst is 1220 mA&#183;h/g (based on the total electrode mass) at a current density of 0.1 mA/cm2, and the capacity retention rate is about 47.3% after 13 charge-discharge cycles. The results of charge-discharge cycling tests demonstrate that this novel Pd-coatedα-MnO2 catalyst with a hierarchical core-shell structure is a promising catalyst for the lithium-air battery. 展开更多
关键词 lithium-air battery composite catalyst nanoneedle-based hollow microsphere core-shell structure
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Photocatalytic Degradation of Phenol over MWCNTs-TiO2 Composite Catalysts with Different Diameters
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作者 李晨 汪文栋 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第4期423-428,448,共7页
Titania-based composite catalysts were prepared through a sol-gel route employing multi-walled carbon nanotubes with different diameters. The materials were characterized using thermogravimetric analysis, nitrogen ads... Titania-based composite catalysts were prepared through a sol-gel route employing multi-walled carbon nanotubes with different diameters. The materials were characterized using thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy, and diffuse reflectance UV-Vis absorption spectra. The application of the catalysts to photocatalytic degradation of phenol was tested under UV-Vis irradiation. A synergetic effect on phenol removal was observed in case of composite catalysts, which was evaluated in terms of apparent rate constant, total organic carbon removal and photonic efficiency. 展开更多
关键词 Photocatalytic degradation PHENOL Titanium dioxide Multi-walled carbon nanotube Composite catalyst
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Post-synthetic modification strategy to construct Co-MOF composites for boosting oxygen evolution reaction activity
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作者 ZHENG Haifeng GUO Xingzhe +5 位作者 WEI Yunwei WANG Xinfang QI Huimin YAN Yuting ZHANG Jie LI Bingwen 《无机化学学报》 北大核心 2026年第1期193-202,共10页
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul... The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276. 展开更多
关键词 PYRENE metal-organic frameworks composite catalyst oxygen evolution reaction density functional theory
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Effects of cerium precursors on surface properties of mesoporous CeMnO_x catalysts for toluene combustion 被引量:8
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作者 Changyu Zhang Wei Chu +3 位作者 Feng Chen Lei Li Ruiyu Jiang Jinlong Yan 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第1期70-75,共6页
Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce... Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce(NO3)6] on catalyst structure,surface properties and toluene combustion activities of mesoporous CeMnOx catalysts were investigated.The Ce(Ⅲ)MnOx catalyst prepared from Ce(NO3)3 precursor shows higher catalytic activity,with a 90% conversion temperature of 240℃,which is better than the Ce(Ⅳ)MnOx catalyst derived from[(NH4)2 Ce(NO3)6] precursor.On the basis of characterizations,it reveals that abundant surface content of Mn4+,better redox behavior and larger concentration of surface active oxygen species are responsible for the excellent catalytic performance. 展开更多
关键词 Cerium precursor CeMnOx composite catalyst Synergistic effect Catalytic combustion TOLUENE Rare earths
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Synthesis and Photocatalytic Activity of TiO_2/V_2O_5 Composite Catalyst Doped with Rare Earth Ions 被引量:6
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作者 刘建华 杨蓉 李松梅 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第2期173-178,共6页
TiO2/V2O5 catalyst doped with rare earth ions was prepared by sol-gel method. Titanium tetrapropoxide and vanadium pentoxide were used as precursor of the composite catalyst and rare earth ions were used as dopant. Th... TiO2/V2O5 catalyst doped with rare earth ions was prepared by sol-gel method. Titanium tetrapropoxide and vanadium pentoxide were used as precursor of the composite catalyst and rare earth ions were used as dopant. The crystal phases, crystalline sizes, microstructure, absorption spectra of doped composite catalyst were studied by XRD, EDS, FT-IR and UV-Vis. Photoactivity of the prepared catalyst under ultraviolet irradiation were evaluated by degradation of methyl orange (MO) in aqueous solution. It is shown that the prepared catalyst is composed of anatase and futile. The rare earth ions are highly dispersed in composite catalyst. All the doped catalysts appear higher photocatalytic activity than TiO2/V2O5 catalyst and catalyst doped with Ce^4+ present the best activity to MO. 展开更多
关键词 PHOTOCATALYSIS titanium dioxide composite catalyst rare earth ion CERIUM
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Preparation and characterization of the TiO_2-V_2O_5 photocatalyst with visible-light activity 被引量:7
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作者 LIU Jianhua YANG Rong LI Songmei 《Rare Metals》 SCIE EI CAS CSCD 2006年第6期636-642,共7页
Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level.... Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline (PANI) by means of in-situ polymerization of aniline. Conglomeration of the TiO2-V2O5 dusters during the calcination process was avoided because of the wrap of polyaniline. The surface mor- phology, the crystal phases, the structure, and the absorption spectra of (PANI),/TiO2-V2O5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue (MB) solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO2: V2O5 = 10:1 presented the best photocatalytic activity. 展开更多
关键词 inorganic non-metal materials visible-light active photocatalyst binary sol-gel synthesis composite catalyst
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Photocatalytic degradation of imidacloprid by composite catalysts H_3PW_(12)O_(40)/La-TiO_2 被引量:3
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作者 冯长根 徐刚 刘霞 《Journal of Rare Earths》 SCIE EI CAS CSCD 2013年第1期44-48,共5页
A series of La-doped TiO2 with different mass fractions were prepared by sol-gel method. Composite catalysts H3PW12O40/La-TiO2 with different loading levels were synthesized using impregnation method. The prepared sam... A series of La-doped TiO2 with different mass fractions were prepared by sol-gel method. Composite catalysts H3PW12O40/La-TiO2 with different loading levels were synthesized using impregnation method. The prepared samples were charac- terized by foutler transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), UV vis diffuse reflectance spectroscopy (DRS) and nitrogen adsorption-desorption analysis. The Keggin structure of H3PWI2040 (HPW) re- mained intact on the surface of the composites, they had relatively uniform spherical grains of diameter less than 20 nm. The visible light activity of prepared composites were improved by loading HPW and doping La. The prepared composites were used as photo- catalysts in degradation of pesticide imidacloprid. Results revealed that 20%H3PWL204o/0.3%La-TiO2 possessed the best photocata- lyric activity. Thus, the degradation conversion of imidacloprid reached 98.17% after 60 rain irradiation when 20%H3PW12O4/0.3% La-TiO2 was used as catalysts. The degradation of imidacloprid corresponded with first-order kinetic reaction, and the half life of the degradation of imidacloprid was 9.35 min in the optimal conditions. 展开更多
关键词 PHOTOCATALYTIC composite catalysts rare earths IMIDACLOPRID
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The carboxylates formed on oxides promoting the aromatization in syngas conversion over composite catalysts 被引量:2
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作者 Zhiyang Chen Youming Ni +3 位作者 Fuli Wen Ziqiao Zhou Wenliang Zhu Zhongmin Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第5期835-843,共9页
Syngas to aromatics(STA)over bifunctional catalysts has attracted much attention in recent years,but the mechanism underlying the formation of aromatics remains controversial.The critical reaction intermediates,carbox... Syngas to aromatics(STA)over bifunctional catalysts has attracted much attention in recent years,but the mechanism underlying the formation of aromatics remains controversial.The critical reaction intermediates,carboxylates,were first identified and then confirmed to essentially promote aromatization in the syngas conversion over a ZnCrAlO_(x)&H-ZSM-5 composite catalyst.This study provides evidence that the carboxylates can be formed during the reactions of formate species and olefins.In addition,it is shown that the carboxylates favor the formation of aromatics over H-ZSM-5 even in the presence of H2.A novel mechanism for the formation of aromatics via the generation and transformation of carboxylate intermediates is proposed,and the transformation of carboxylates to aromatics via methyl-2-cyclopenten-1-one(MCPO)intermediates is indeed likely.A better understanding of the formation mechanism of aromatics would help optimize the composite catalyst. 展开更多
关键词 CARBOXYLATES Syngas-to-aromatics Composite catalysts ZnCrAlO_(x) H-ZSM-5
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Insights into effects of ZrO_(2) crystal phase on syngas‐to‐olefin conversion over ZnO/ZrO_(2) and SAPO‐34 composite catalysts 被引量:3
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作者 Zhaopeng Liu Youming Ni +6 位作者 Zhongpan Hu Yi Fu Xudong Fang Qike Jiang Zhiyang Chen Wenliang Zhu Zhongmin Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第3期877-884,共8页
The utilization of metal oxide‐zeolite catalysts in the syngas‐to‐olefin reaction is a promising strategy for producing C_(2)–C_(4) olefins from non‐petroleum resources.However,the effect of the crystal phase of ... The utilization of metal oxide‐zeolite catalysts in the syngas‐to‐olefin reaction is a promising strategy for producing C_(2)–C_(4) olefins from non‐petroleum resources.However,the effect of the crystal phase of metal oxides on the catalytic activity of these oxides is still ambiguous.Herein,typical metal oxides(ZnO/ZrO_(2))with different crystal phases(monoclinic(m‐ZrO_(2))and tetragonal(t‐ZrO_(2)))were employed for syngas conversion.The(ZnO/m‐ZrO_(2)+SAPO‐34)composite catalyst exhibited 80.5%selectivity for C_(2)–C_(4) olefins at a CO conversion of 27.9%,where the results are superior to those(CO conversion of 16.4%and C_(2)–C_(4) olefin selectivity of 76.1%)obtained over(ZnO/t‐ZrO_(2)+SAPO‐34).The distinct differences are ascribed to the larger number of hydroxyl groups,Lewis acid sites,and oxygen defects in ZnO/m‐ZrO_(2) compared to ZnO/t‐ZrO_(2).These features result in the formation of more formate and methoxy intermediate species on the ZnO/m‐ZrO_(2) oxides during syngas conversion,followed by the formation of more light olefins over SAPO‐34.The present findings provide useful information for the design of highly efficient ZrO_(2)‐based catalysts for syngas conversion. 展开更多
关键词 Syngas‐to‐olefins Crystal phase ZnO/ZrO_(2) SAPO‐34 Composite catalyst
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Dysprosium regulated platinum particles as a bimetallic alloy catalyst for oxygen reduction reaction 被引量:2
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作者 Qianru Liu Juan Qin +3 位作者 Fengyun Huang Dawei Zhang Liheng Chen Feng Yin 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第8期1189-1194,I0003,共7页
Pt rare earth compounds have recently been investigated as potential substitutes.In this study,the hydrogen reduction method was used to prepare the Pt-Dy bimetallic catalyst,and a number of characterizations were con... Pt rare earth compounds have recently been investigated as potential substitutes.In this study,the hydrogen reduction method was used to prepare the Pt-Dy bimetallic catalyst,and a number of characterizations were conducted for structure and morphological research.The high resolutiontransmission electron microscopy(HR-TEM)and X-ray diffraction results show that Pt-Dy composite material exists in the form of various alloys and has a clear spherical shape.The majority of the metals in the composite catalyst appear in the zero valent state,and the binding energy of Pt shifts significantly,according to an X-ray photoelectron spectroscopy measurement.Impressively,Pt-Dy alloy produces excellent mass activity of 594 A/g compared to commercial Pt/C catalyst(162.8 A/g)for oxygen reduction process.Furthermore,after an accele rated durability test,the catalytic activity loss for Pt-Dy alloy catalyst reaches 20%while commercial Pt/C reduces 56%. 展开更多
关键词 Rare earth metal Pt metal Composite catalyst Oxygen reduction reaction
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3D hierarchically macro-/mesoporous graphene frameworks enriched with pyridinic-nitrogen-cobalt active sites as efficient reversible oxygen electrocatalysts for rechargeable zinc-air batteries 被引量:1
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作者 Sheng Zhou Jiayi Qin +1 位作者 Xueru Zhao Jing Yang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第4期571-582,共12页
Efficient and affordable electrocatalysts for reversible oxygen reduction and oxygen evolution reactions(ORR and OER,respectively)are highly sought-after for use in rechargeable metal-air batteries.However,the constru... Efficient and affordable electrocatalysts for reversible oxygen reduction and oxygen evolution reactions(ORR and OER,respectively)are highly sought-after for use in rechargeable metal-air batteries.However,the construction of high-performance electrocatalysts that possess both largely accessible active sites and superior ORR/OER intrinsic activities is challenging.Herein,we report the design and successful preparation of a 3D hierarchically porous graphene framework with interconnected interlayer macropores and in-plane mesopores,enriched with pyridinic-nitrogen-cobalt(pyri-N-Co)active sites,namely,CoFe/3D-NLG.The pyri-N-Co bonding significantly accelerates sluggish oxygen electrocatalysis kinetics,in turn substantially improving the intrinsic ORR/OER activities per active site,while copious interlayer macropores and in-plane mesopores enable ultra-efficient mass transfer throughout the graphene architecture,thus ensuring sufficient exposure of accessible pyri-N-Co active sites to the reagents.Such a robust catalyst structure endows CoFe/3D-NLG with a remarkably enhanced reversible oxygen electrocatalysis performance,with the ORR half-wave potential identical to that of the benchmark Pt/C catalyst,and OER activity far surpassing that of the noble-metal-based RuO2 catalyst.Moreover,when employed as an air electrode for a rechargeable Zn-air battery,CoFe/3D-NLG manifests an exceedingly high open-circuit voltage(1.56 V),high peak power density(213 mW cm^(–2)),ultra-low charge/discharge voltage(0.63 V),and excellent charge/discharge cycling stability,outperforming state-of-the-art noble-metal electrocatalysts. 展开更多
关键词 Hierarchical pores Composite catalyst Oxygen electrocatalysis Spinel oxide Rechargeable zinc-air battery
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Synthesis and Application of a Zeolite-containing Composite Material Made from Spent FCC Catalyst 被引量:3
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作者 Zheng Shuqin He Lijun +3 位作者 Yao Hua Ren Shao Yu Hongxia Zhang Jiance 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第4期46-54,共9页
Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.... Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.7% of zeolite Y and exhibited a much larger specific surface area and pore volume as well as strong hydrothermal stability. Fluid catalytic cracking(FCC) catalyst was prepared based on the composite material. The results indicated that the as-prepared catalyst possessed a unique pore structure that was advantageous to the diffusion-controlled reactions. In addition, the attrition resistance, activity and hydrothermal stability of the studied catalyst were superior to those of the reference catalyst. The catalyst also exhibited excellent nickel and vanadium passivation performance, strong bottoms upgrading selectivity, and better gasoline and coke selectivity. In comparison to the reference catalyst, the yields of the gasoline and light oil increased by 1.61 and 1.31 percentage points, respectively, and the coke yield decreased by 0.22 percentage points, and the olefin content in the produced gasoline reduced by 2.51 percentage points, with the research octane number increased by 0.7 unit. 展开更多
关键词 FCC spent catalyst composite material porous structure resid catalyst catalytic properties
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Synthesis of La_2MoO_6@MWCNTs composite catalysts as Pt-free counter electrodes for dye-sensitized solar cell 被引量:1
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作者 Kezhong Wu Jiajing Zhao +2 位作者 Yuanyuan Xiong Bei Ruan Mingxing Wu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第12期1278-1283,共6页
Pt-free counter electrode(CE) composed of La2 MoO(LaO-MoO) was successfully synthesized by simple pyrolysis of lanthanum acetate(CHOLa·xHO) and hexaammonium heptamolybdate tetrahydrate((NH4)6 MoO·4 HO). Furt... Pt-free counter electrode(CE) composed of La2 MoO(LaO-MoO) was successfully synthesized by simple pyrolysis of lanthanum acetate(CHOLa·xHO) and hexaammonium heptamolybdate tetrahydrate((NH4)6 MoO·4 HO). Furthermore,three proportions composites catalysts of La2 MoO@MWCNTs based on La2 MoOand multiwall carbon nanotubes(MWCNTs) were prepared and characterized as Ptfree catalyst for CE in dye-sensitized solar cells(DSSCs). The morphology and structure of La2 MoO@MWCNTs composites were determined by scanning electron microscopy, transmission electron microscope and X-ray diffraction. The electrochemical performance of La2 MoO@MWCNTs composite catalysts for CEs was determined by photocurrent-voltage measurements, cyclic voltammetry,electrochemical impedance spectroscopy, and Tafel polarization. The power conversion efficiencies of4.68%, 4.87% and 5.06% are obtained for La2 MoO:MWCNTs with the mass ratios of 5:1, 3:1 and 1:1 towards the reduction of I~-to I~-under the same conditions,respectively,which are superior to those of MWCNTs(3,94%) and La2 MoO(1.71%) electrodes. The experimental results reveal that the presence of MWCNTs results in an augmented active catalytic surface area and enhanced charge transfer from CE to the electrolyte. 展开更多
关键词 Dye-sensitized solar cell Counter electrode Metal composite oxide Composite catalysts Power conversion efficiency Rare earths
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Effect of boron addition on the MoO_3/CeO_2–Al_2O_3 catalyst in the sulfur-resistant methanation 被引量:2
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作者 Baowei Wang Wenxia Yu +3 位作者 Weihan Wang Zhenhua Li Yan Xu Xinbin Ma 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第3期509-513,共5页
The effect of boron on the performance of MoO_3/CeO_2–Al_2O_3 catalysts, which were prepared with impregnation method, was investigated. The catalysts were characterized with N_2 adsorption–desorption, XRD, H_2-TPR,... The effect of boron on the performance of MoO_3/CeO_2–Al_2O_3 catalysts, which were prepared with impregnation method, was investigated. The catalysts were characterized with N_2 adsorption–desorption, XRD, H_2-TPR, and NH_3-TPD, and were tested in sulfur-resistant methanation. The results indicated that the MoO_3/CeO_2–Al_2O_3 catalysts modified by boron showed higher catalytic performance in sulfur-resistant methanation. The CO conversion increased from 47% to 62% with 0.5 wt% boron content. When the content of boron was under 0.5 wt%, the results suggested there was an increase in the amorphous form of MoO_3 caused by the generation of weak and intermediate acid sites, which had weakened the interaction between the active components and supports. While, the catalyst added 2.0 wt% boron showed the strong acid sites and the largest crystalline size resulting in the uneven distribution of ceria. 展开更多
关键词 Boron Sulfur-resistant Methanation Mo-based catalyst Composite support
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Synthesis and study of λ-MnO_2 supported Pt nanocatalyst for methanol electro-oxidation 被引量:3
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作者 XIE Jia, LI Xiang, YU Zhihui, ZHANG Lijuan, LI Fan, and XIA Dingguo College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China 《Rare Metals》 SCIE EI CAS CSCD 2010年第2期187-192,共6页
A λ-MnO2 supported Pt nanocatalyst(5 wt.% Pt/λ-MnO2) was synthesized using a facile approach.X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electronic microscope(SEM), transmission e... A λ-MnO2 supported Pt nanocatalyst(5 wt.% Pt/λ-MnO2) was synthesized using a facile approach.X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electronic microscope(SEM), transmission electron microscopy(TEM), and energy disperse spectroscopy(EDS) were used for catalyst structure and morphology characterization, which showed that the metallic Pt particles were attached on a λ-MnO2 surface through the interaction between Pt and λ-MnO2.Cyclic voltammetry(CV) was used to test the catalytic activity of Pt/λ-MnO2 toward methanol oxidation, which showed that Pt/λ-MnO2 catalyst has much higher catalytic activity than baseline Pt/C catalyst. 展开更多
关键词 electrochemistry composite catalyst MnO2 Pt methanol oxidation
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Selective oxidation of benzyl alcohols to benzoic acid catalyzed by eco-friendly cobalt thioporphyrazine catalyst supported on silica-coated magnetic nanospheres 被引量:2
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作者 Huan Li Lan Cao +3 位作者 Changjun Yang Zhehui Zhang Bingguang Zhang Kejian Deng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第10期84-90,共7页
A novel magnetically recoverable thioporphyrazine catalyst(CoPz(S-Bu)8/SiO2@Fe3O4) was prepared by immobilization of the cobalt octkis(butylthio) porphyrazine complex(CoPz(S-Bu)8) on silica-coated magnetic n... A novel magnetically recoverable thioporphyrazine catalyst(CoPz(S-Bu)8/SiO2@Fe3O4) was prepared by immobilization of the cobalt octkis(butylthio) porphyrazine complex(CoPz(S-Bu)8) on silica-coated magnetic nanospheres(SiO2@Fe3O4). The composite CoPz(S-Bu)8/SiO2@Fe3O4appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide(H2O2) as oxidant under Xe-lamp irradiation,with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number(TON) of 61.7 at ambient temperature. The biomimetic catalyst CoPz(S-Bu)8was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz(S-Bu)8can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications. 展开更多
关键词 Cobalt thioporphyrazine Magnetic nanospheres Composite catalyst Photocatalytic oxidation Substituted benzyl alcohol Benzoic acid
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