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Pt–Ba–Ce/γ-Al2O3 催化剂,物理化学性质,NOx存储和还原,NOx 排放,H2 还原剂 1

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A facile synthesis of high activity cube-like Pt/carbon composites for fuel cell application

Reza B. MOGHADDAM, Samaneh SHAHGALDI, Xianguo LI

《能源前沿(英文)》 2017年 第11卷 第3期   页码 245-253 doi: 10.1007/s11708-017-0492-4

摘要: High activity catalyst with simple low-cost synthesis is essential for fuel cell commercialization. In this study, a facile procedure for the synthesis of cube-like Pt nanoparticle (Pt ) composites with high surface area carbon supports is developed by mixing precursor of Pt with carbon supports in organic batches, hence, one pot synthesis. The Pt grow with Vulcan XC-72 or Ketjen black, respectively, and then treated for 5.5 h at 185ºC (i.e., Pt /V and Pt /K). The resulting particle sizes and shapes are similar; however, Pt /K has a larger electrochemical active surface area (EASA) and a remarkably better formic acid (FA) oxidation performance. Optimization of the Pt /K composites leads to Pt /K that has been treated for 10 h at 185ºC. With a larger EASA, Pt /K is also more active in FA oxidation than the other Pt /K composites. Impedance spectroscopy analysis of the temperature treated and as-prepared (i.e., untreated) Pt /K composites indicates that Pt /K is less resistive, and has the highest limiting capacitance among the Pt /K electrodes. Consistently, the voltammetric EASA is the largest for Pt /K. Furthermore, Pt /K is compared with two commercial Pt/C catalysts, Tanaka Kikinzoku Kogyo (TKK), and Johnson Matthey (JM)Pt/C catalysts. The TKK Pt/C has a higher EASA than Pt /K, as expected from their relative particles sizes (3–4 nm vs. 6–7 nm for Pt /K), however, Pt /K has a significantly better FA oxidation activity.

关键词: synthesis     cube-like Pt     Pt/C composite     catalyst     impedance    

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

《环境科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 483-495 doi: 10.1007/s11783-013-0595-z

摘要: A novel Ultrasonic Assisted Membrane Reduction (UAMR)-hydrothermal method was used to prepare flower-like Pt/CeO catalysts. The texture, physical/chemical properties, and reducibility of the flower-like Pt/CeO catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), N adsorption, and hydrogen temperature programmed reduction (H -TPR) techniques. The catalytic performance of the catalysts for treating automobile emission was studied relative to samples prepared by the conventional wetness impregnation method. The Pt/CeO catalysts fabricated by this novel method showed high specific surface area and metal dispersion, excellent three-way catalytic activity, and good thermal stability. The strong interaction between the Pt nanoparticles and CeO improved the thermal stability. The Ce ions were incorporated into the surfactant chains and the Pt nanoparticles were stabilized through an exchange reaction of the surface hydroxyl groups. The SEM results demonstrated that the Pt/CeO catalysts had a typical three-dimensional (3D) hierarchical porous structure, which was favorable for surface reaction and enhanced the exposure degree of the Pt nanoparticles. In brief, the flower-like Pt/CeO catalysts prepared by UAMR-hydrothermal method exhibited a higher Pt metal dispersion, smaller particle size, better three-way catalytic activity, and improved thermal stability versus conventional materials.

关键词: three-way catalyst     flower-like     Ultrasonic Assisted Membrane Reduction (UAMR)     Pt nanoparticles    

Construction of digital 3D magic-cube organization structure for innovation-driven manufacturing

《工程管理前沿(英文)》   页码 373-390 doi: 10.1007/s42524-022-0237-x

摘要: Owing to the heterogeneity between functional units and resource scarcity, manufacturing firms have been struggling with intra-organizational coordination for productivity and innovation. Traditional organizational structures, such as linear-functional and matrix, may cause responsibility division and independent goals (Shahani, 2020), and are more difficult to be adopted by large-sized innovative manufacturing firms for quantity production. This is based on a review of several new forms of organization (i.e., network organization, multiteam system, and platform organization) compared with the traditional forms of organization (i.e., linear, matrix, and business unit organization, among others). This study proposes a three-dimensional (3D) magic-cube organizational structure, considering the product dimensions, business, and administration. Moreover, the characteristics, propositions of system operation, system dynamic model, and working model of the 3D magic-cube organization are described. Finally, the 3D model is applied in a Chinese manufacturing firm to test its effectiveness. By redesigning the post and pay system, the pilot organization establishes a project-driven and cross-functional coordination mechanism, positively affecting the firm’s financial profit, output value, labor productivity, and income of per capita. The proposed 3D model can be adopted by large- or medium-sized manufacturing firms for product development and innovation. The implications of both practice and theory are also discussed in this study.

关键词: innovation     manufacturing     3D magic-cube organization structure     coordination    

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

《化学科学与工程前沿(英文)》 2022年 第16卷 第3期   页码 397-407 doi: 10.1007/s11705-021-2076-4

摘要: The catalytic hydrogenation of carboxylic acid to alcohols is one of the important strategies for the conversion of biomass. Herein, a series of Ni-doped PtSn catalysts were prepared, characterized and studied in the hydrogenation of acetic acid. The Ni dopant has a strong interaction with Pt, which promotes the hydrogen adsorption, providing an activated hydrogen-rich environment for the hydrogenation. Meanwhile, the presence of Ni also improves the Pt dispersion, giving more accessible active sites for hydrogen activation. The cooperation of Pt and Ni significantly promotes the catalytic activity of the hydrogenation of acetic acid to ethanol. As a result, the catalyst with 0.1% Ni exhibits the best reaction activity, and its space time yield is twice as that of the PtSn/SiO2 catalyst. It provides a meaningful instruction on the catalyst design for the carboxylic acid hydrogenation.

关键词: acetic acid     ethanol     hydrogenation     Pt     Ni     cooperation effect    

Pt–C interactions in carbon-supported Pt-based electrocatalysts

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1677-1697 doi: 10.1007/s11705-023-2300-5

摘要: Carbon-supported Pt-based materials are highly promising electrocatalysts. The carbon support plays an important role in the Pt-based catalysts by remarkably influencing the growth, particle size, morphology, dispersion, electronic structure, physiochemical property and function of Pt. This review summarizes recent progress made in the development of carbon-supported Pt-based catalysts, with special emphasis being given to how activity and stability enhancements are related to Pt–C interactions in various carbon supports, including porous carbon, heteroatom doped carbon, carbon-based binary support, and their corresponding electrocatalytic applications. Finally, the current challenges and future prospects in the development of carbon-supported Pt-based catalysts are discussed.

关键词: Pt–C interactions     Pt-based materials     carbon support     electrocatalysis    

Decoration of CdMoO micron polyhedron with Pt nanoparticle and their enhanced photocatalytic performance

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1949-1961 doi: 10.1007/s11705-023-2360-6

摘要: This study aimed to prepare and apply a novel Pt/CdMoO4 composite photocatalyst for photocatalytic N2 fixation and tetracycline degradation. The Pt/CdMoO4 composite was subjected to comprehensive investigation on the morphology, structure, optical properties, and photoelectric chemical properties. The results demonstrate the dispersion of Pt nanoparticles on the CdMoO4 surface. Close contact between CdMoO4 and Pt was observed, resulting in the formation of a heterojunction structure at their contact region. Density functional theory calculation and Mott-Schottky analysis revealed that Pt possesses a higher work function value than CdMoO4, resulting in electron drift from CdMoO4 to Pt and the formation of a Schottky barrier. The presence of this barrier increases the separation efficiency of electron-hole pairs, thereby improving the performance of the Pt/CdMoO4 composite in photocatalysis. When exposed to simulated sunlight, the optimal Pt/CdMoO4 catalyst displayed a photocatalytic nitrogen fixation rate of 443.7 μmol·L‒1·g‒1·h‒1, which is 3.2 times higher than that of pure CdMoO4. In addition, the composite also exhibited excellent performance in tetracycline degradation, with hole and superoxide species identified as the primary reactive species. These findings offer practical insights into designing and synthesizing efficient photocatalysts for photocatalytic nitrogen fixation and antibiotics removal.

关键词: photocatalytic N2 fixation     Pt/CdMoO4     tetracycline degradation     Schottky barrier    

Highly selective catalytic hydrodeoxygenation of guaiacol to cyclohexane over Pt/TiO

Zhong HE,Xianqin WANG

《化学科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 369-377 doi: 10.1007/s11705-014-1435-9

摘要: Catalysts Pt/TiO and NiMo/Al O are highly active and selective for the hydrodeoxygenation of guaiacol in a fixed bed reactor at 300 °C and 7.1 MPa, leading to the hydrogenation of aromatic ring, followed by demethylation and dehydroxylation to produce cyclohexane. For a complete hydrodeoxygenation of guaiacol, metal sites and acid sites are required. NiMo/Al O and Pt/Al O are more active and selective for cyclohexane formation as compared with Pt/TiO at 285 °C and 4 MPa. However, Pt/TiO is stable while the other two catalysts deactivate due to the nature and amount of coke formation during the reaction.

关键词: Pt/TiO2     NiMo/Al2O3     Pt/Al2O3     bio-oil     hydrodeoxygenation     guaiacol     cyclohexane    

Concentrations of anthropogenic Pt and Pd in urban roadside soils in Xuzhou, China

WANG Xuesong, SUN Cheng

《环境科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 475-479 doi: 10.1007/s11783-008-0071-3

摘要: The potential accumulation of platinum group elements (PGE) in the environment from automobile catalysts is high in urban areas, with the major sinks being roadside soils. Therefore, this investigation presented the detailed study on characterized concentrations of Pt and Pd and their enrichment ratios in urban roadside soils in Xuzhou, China in March 2003. Data from 21 roadside topsoil samples analyzed by inductively coupled plasma-mass spectrometer (ICP-MS) illustrated that the medians of concentrations of Pt and Pd were 2.9 and 2.8 ng/g, respectively. Hierarchical clustering analysis indicated that Pt and Pd were mainly from traffic emissions. Compared to unpolluted soils, computation of Pt and Pd enrichment ratios suggested that the Xuzhou roadside soils had average enrichment factors of 3.53 for Pt (in range of 1.22–5.73) and of 3.37 for Pd (in range of 1.35–4.46). Lower Pt/Pd ratios (in range of 0.35–2.86) in relation to similar studies in other countries were observed, which might be due to the different Pt/Pd ratios in Chinese automobile catalytic converters. Moreover, fine fraction (<250 ?m) contained higher concentrations of Pt and Pd compared to the coarse fraction (250–500 ?m).

关键词: platinum     detailed     different     Hierarchical     automobile catalytic    

Efficient synthesis of titania nanotubes and enhanced photoresponse of Pt decorated TiO

Yuxin YIN, Xin TAN, Feng HOU, Lin ZHAO

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 298-304 doi: 10.1007/s11705-009-0019-6

摘要: We investigated the effect of HMT (hexamethylenetetraamine) on the anodic growth of TiO nanotube arrays. The tube length increases to 4.3 μm with HMT concentration increasing to 0.04 mol·L . Adsorption of HMT on the TiO surface is shown to markedly decrease the chemical dissolution rate of tube mouth, resulting in longer nanotube length. Furthermore, Pt nanoparticles were successfully deposited on the surface of TiO nanotubes by ac electrodeposition method. The TiO /Pt composites were characterized by field emission scanning electron microscope (FESEM), X-ray photoelectron spectra (XPS), and photoelectrochemistry. An enhancement in photocurrent density has been achieved upon modification of TiO nanotubes with Pt nanoparticles.

关键词: TiO2 nanotube arrays     HMT     TiO2/Pt     Photocurrent density    

Thermoresponsive block copolymer supported Pt nanocatalysts for base-free aerobic oxidation of 5-hydroxymethyl

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1514-1523 doi: 10.1007/s11705-021-2092-4

摘要: A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazole) block copolymer, with an upper critical solution temperature of about 45 °C. The Pt nanocatalysts were well-dispersed and highly active for the base-free oxidation of 5-hydroxymethyl-2-furfural by molecular oxygen in water, affording high yields of 2,5-furandicarboxylic acid (up to>99.9%). The imidazole groups in the block copolymer were conducive to the improvement of catalytic performance. Moreover, the catalysts could be easily separated and recovered based on their thermosensitivity by cooling the reaction system below the upper critical solution temperature. Good stability and reusability were observed over these copolymer-immobilized catalysts with no obvious decrease in catalytic activity in the five consecutive cycles.

关键词: aerobic oxidation     base-free     5-hydroxymethyl-2-furfural     Pt nanoparticle     thermoresponsive block copolymer    

Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

《环境科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 482-487 doi: 10.1007/s11783-007-0077-2

摘要: Catalytic ozonation of aqueous solutions of oxalic acid was examined in the presence of graphite-supported platinum catalysts. The catalytic activity of graphite was significantly enhanced by loading platinum. The removal efficiency of oxalic acid was 3.0%, 47.6% and 99.3% for ozonation alone, graphite catalytic ozonation and Pt/graphite catalytic ozonation in 30 min under the experimental condition, respectively. The influence of support pretreatment, solvent, impregnation time, platinum loading amount and reduction temperature on the activity of Pt/graphite catalyst was investigated. The pretreatment of graphite support had no effect on activity improvement of Pt/graphite catalyst. Solvent and impregnation time also had no great effect on the activity. Platinum loading amount and reduction temperature influenced the catalyst activity significantly. The optimal catalytic performance of Pt/graphite was obtained when 1.0% platinum loading and 623 K of reduction temperature was adopted. The Pt/graphite catalyst was used for five times with no significant decrease in its activity and more than 90% oxalic acid removal was obtained.

The effect of preparation conditions of Pt/Al

Lei YUAN, Xiang ZHENG, Kaijiao DUAN, Hao HU, Jinggang WANG, Seong Ihl WOO, Zhiming LIU

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 457-463 doi: 10.1007/s11783-013-0512-5

摘要: Selective catalytic reduction of NO by H in the presence of oxygen has been investigated over Pt/Al O catalysts pre-treated under different conditions. Catalyst preparation conditions exert significant influence on the catalytic performance, and the catalyst pre-treated by H or H then followed by O is much more active than that pre-treated by air. The higher surface area and the presence of metallic Pt over Pt/Al O pre-treated by H or pretreated by H then followed by O can contribute to the formation of NO , which then promotes the reaction to proceed at low temperatures.

关键词: NOx reduction     Pt/Al2O3     preparation condition     H2-SCR    

The synergic effects of highly selective bimetallic Pt-Pd/SAPO-41 catalysts for the

Guozhi Jia, Chunmu Guo, Wei Wang, Xuefeng Bai, Xiaomeng Wei, Xiaofang Su, Tong Li, Linfei Xiao, Wei Wu

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1111-1124 doi: 10.1007/s11705-020-2031-9

摘要: The hydroisomerization of -hexadecane over Pt-Pd bimetallic catalysts is an effective way to produce clean fuel oil. This work reports a useful preparation method of bimetallic bifunctional catalysts by a co-impregnation or sequential impregnation process. Furthermore, monometallic catalysts with loading either Pt or Pd are also prepared for comparison. The effects of the metal species and impregnation order on the characteristics and catalytic performance of the catalysts are investigated. The catalytic test results indicate that the maximum -hexadecane yield over different catalysts increases as follows: Pt/silicoaluminophosphate SAPO-41

关键词: SAPO-41 molecular sieve     Pt-Pd bimetallic site     bifunctional catalysts     n-hexadecane     hydroisomerization    

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

《能源前沿(英文)》 2017年 第11卷 第3期   页码 268-285 doi: 10.1007/s11708-017-0466-6

摘要: Development of active and durable electrocatalyst for oxygen reduction reaction (ORR) remains one challenge for the polymer electrolyte membrane fuel cell (PEMFC) technology. Pt-based nanomaterials show the greatest promise as electrocatalyst for this reaction among all current catalytic structures. This review focuses on Pt-based ORR catalyst material development and covers the past achievements, current research status and perspectives in this research field. In particular, several important categories of Pt-based catalytic structures and the research advances are summarized. Key factors affecting the catalyst activity and durability are discussed. An outlook of future research direction of ORR catalyst research is provided.

关键词: oxygen reduction reaction (ORR)     electrocatalysis     platinum catalyst     activity     durability    

Investigation of fluorescence characterization and electrochemical behavior on the catalysts of nanosized Pt-Rh

Chang-Mao HUNG, Wen-Liang LAI, Jane-Li LIN

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 428-434 doi: 10.1007/s11783-013-0517-0

摘要: This work describes the environmentally friendly technology for oxidation of ammonia (NH ) to form nitrogen at temperatures range from 423K to 673K by selective catalytic oxidation (SCO) over a nanosized Pt-Rh/γ-Al O catalyst prepared by the incipient wetness impregnation method of hexachloroplatinic acid (H PtCl ) and rhodium (III) nitrate (Rh(NO ) ) with γ-Al O in a tubular fixed-bed flow quartz reactor (TFBR). The characterization of catalysts were thoroughly measured using transmission electron microscopy (TEM), three-dimensional excitation-emission fluorescent matrix (EEFM) spectroscopy, UV-Vis absorption, dynamic light-scattering (DLS), zeta potential meter, and cyclic voltammetry (CV). The results demonstrated that at a temperature of 673K and an oxygen content of 4%, approximately 99% of the NH was removed by catalytic oxidation over the nanosized Pt-Rh/γ-Al O catalyst. N was the main product in NH -SCO process. Further, it reveals that the oxidation of NH was proceeds by the over-oxidation of NH into NO, which was conversely reacted with the NH to yield N . Therefore, the application of nanosized Pt-Rh/γ-Al O catalyst can significantly enhance the catalytic activity toward NH oxidation. One fluorescent peak for fresh catalyst was different with that of exhausted catalyst. It indicates that EEFM spectroscopy was proven to be an appropriate and effective method to characterize the Pt clusters in intrinsic emission from nanosized Pt-Rh/γ-Al O catalyst. Results obtained from the CV may explain the significant catalytic activity of the catalysts.

关键词: ammonia (NH3)     nanosized Pt-Rh/γ-Al2O3 catalyst     excitation-emission fluorescent matrix (EEFM)     selective catalytic oxidation (SCO)     tubular fixed-bed reactor (TFBR)    

标题 作者 时间 类型 操作

A facile synthesis of high activity cube-like Pt/carbon composites for fuel cell application

Reza B. MOGHADDAM, Samaneh SHAHGALDI, Xianguo LI

期刊论文

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

期刊论文

Construction of digital 3D magic-cube organization structure for innovation-driven manufacturing

期刊论文

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

期刊论文

Pt–C interactions in carbon-supported Pt-based electrocatalysts

期刊论文

Decoration of CdMoO micron polyhedron with Pt nanoparticle and their enhanced photocatalytic performance

期刊论文

Highly selective catalytic hydrodeoxygenation of guaiacol to cyclohexane over Pt/TiO

Zhong HE,Xianqin WANG

期刊论文

Concentrations of anthropogenic Pt and Pd in urban roadside soils in Xuzhou, China

WANG Xuesong, SUN Cheng

期刊论文

Efficient synthesis of titania nanotubes and enhanced photoresponse of Pt decorated TiO

Yuxin YIN, Xin TAN, Feng HOU, Lin ZHAO

期刊论文

Thermoresponsive block copolymer supported Pt nanocatalysts for base-free aerobic oxidation of 5-hydroxymethyl

期刊论文

Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

期刊论文

The effect of preparation conditions of Pt/Al

Lei YUAN, Xiang ZHENG, Kaijiao DUAN, Hao HU, Jinggang WANG, Seong Ihl WOO, Zhiming LIU

期刊论文

The synergic effects of highly selective bimetallic Pt-Pd/SAPO-41 catalysts for the

Guozhi Jia, Chunmu Guo, Wei Wang, Xuefeng Bai, Xiaomeng Wei, Xiaofang Su, Tong Li, Linfei Xiao, Wei Wu

期刊论文

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

期刊论文

Investigation of fluorescence characterization and electrochemical behavior on the catalysts of nanosized Pt-Rh

Chang-Mao HUNG, Wen-Liang LAI, Jane-Li LIN

期刊论文