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Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layerfor proton exchange membrane fuel cells

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

《能源前沿（英文）》 2023年 第17卷 第1期   页码 123-133 doi: 10.1007/s11708-022-0849-1

摘要： High cost has undoubtedly become the biggest obstacle to the commercialization of proton exchange membrane fuel cells (PEMFCs), in which Pt-based catalysts employed in the cathodic catalyst layer (CCL) account for the major portion of the cost. Although non-precious metal catalysts (NPMCs) show appreciable activity and stability in the oxygen reduction reaction (ORR), the performance of fuel cells based on NPMCs remains unsatisfactory compared to those using Pt-based CCL. Therefore, most studies on NPMC-based fuel cells focus on developing highly active catalysts rather than facilitating oxygen transport. In this work, the oxygen transport behavior in CCLs based on highly active Fe-N-C catalysts is comprehensively explored through the elaborate design of two types of membrane electrode structures, one containing low-Pt-based CCL and NPMC-based dummy catalyst layer (DCL) and the other containing only the NPMC-based CCL. Using Zn-N-C based DCLs of different thickness, the bulk oxygen transport resistance at the unit thickness in NPMC-based CCL was quantified via the limiting current method combined with linear fitting analysis. Then, the local and bulk resistances in NPMC-based CCLs were quantified via the limiting current method and scanning electron microscopy, respectively. Results show that the ratios of local and bulk oxygen transport resistances in NPMC-based CCL are 80% and 20%, respectively, and that an enhancement of local oxygen transport is critical to greatly improve the performance of NPMC-based PEMFCs. Furthermore, the activity of active sites per unit in NPMC-based CCLs was determined to be lower than that in the Pt-based CCL, thus explaining worse cell performance of NPMC-based membrane electrode assemblys (MEAs). It is believed that the development of NPMC-based PEMFCs should proceed not only through the design of catalysts with higher activity but also through the improvement of oxygen transport in the CCL.

关键词： proton exchange membrane fuel cells (PEMFCs)     non-precious metal catalyst (NPMC)     cathode catalyst layer (CCL)     local and bulk oxygen transport resistance    

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用于储能设备的一种新型高导电性和高选择性质子交换膜 Article

Kang Huang, Shuhao Lin, Yu Xia, Yongsheng Xia, Feiyan Mu, Yuqin Lu, Hongyan Cao, Yixing Wang, Weihong Xing, Zhi Xu

《工程（英文）》 2023年 第28卷 第9期   页码 69-78 doi: 10.1016/j.eng.2022.11.008

摘要：

Ion conductive membranes (ICMs) with highly conductive proton selectivity are of significant importance and greatly desired for energy storage devices. However, it is extremely challenging to construct fast proton-selective transport channels in ICMs. Herein, a membrane with highly conductive proton selectivity was fabricated by incorporating porous carbon sieving nanospheres with a hollow structure (HCSNs) in a polymer matrix. Due to the precise ion sieving ability of the microporous carbon shells and the fast proton transport through their accessible internal cavities, this advanced membrane presented a proton conductivity (0.084 S·cm−1) superior to those of a commercial Nafion 212 (N212) membrane (0.033 S·cm−1) and a pure polymer membrane (0.049 S·cm−1). The corresponding proton selectivity of the membrane (6.68 × 105 S·min·cm−3) was found to be enhanced by about 5.9-fold and 4.3-fold, respectively, compared with those of the N212 membrane (1.13 × 105 S·min·cm−3) and the pure membrane (1.56 × 105 S·min·cm−3). Low-field nuclear magnetic resonance (LF-NMR) clearly revealed the fast proton-selective transport channels enabled by the HCSNs in the polymeric membrane. The proposed membrane exhibited an outstanding energy efficiency (EE) of 84% and long-term stability over 1400 cycles with a 0.065% capacity decay per cycle at 120 mA·cm−2 in a typical vanadium flow battery (VFB) system.

关键词： Ion conductive membrane     Hollow carbon sieving nanosphere     Proton transport channel     Flow battery    

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西部铁路通道建设及政策措施

孙永福

《中国工程科学》 2010年 第12卷 第6期   页码 18-24

摘要：

在分析西部铁路客货运输需求的基础上，提出目前存在的主要问题，强调了建设铁路运输通道的必要性。阐明了西部铁路网发展目标、铁路通道建设原则，以及区域通道、内部通道、国际通道等主要建设项目规划，并提出了加快西部铁路通道建设的若干政策措施。

关键词： 西部铁路     通道建设     运输能力     投融资改革     铁路运价    

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光传送网中光监控通道信号Q值在线监测技术

唐勇,孙小菡,张明德,丁东

《中国工程科学》 2001年 第3卷 第12期   页码 71-75

摘要：

提出了一种带有光监控通道（OSC）子系统的光传送网（OTN）分层结构模型，分析了OSC中的信号特点，指出OSC信号质量决定了运行、管理和维护（OAM）信号的可靠性。依据Q值与误码率（BER）的一一对应关系，提出了一种可在线监测OSC信号Q值的方案，并基于数字信号处理芯片（DSP）技术设计了监测模块，实现了OSC信号在线Q值监测。

关键词： 光传送网（OTN）     光监控通道（OSC）     运行、管理和维护（OAM）     Q值监测    

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TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

《能源前沿（英文）》 2022年 第16卷 第5期   页码 852-861 doi: 10.1007/s11708-021-0811-7

摘要： Fuel starvation can occur and cause damage to the cell when proton exchange membrane fuel cells operate under complex working conditions. In this case, carbon corrosion occurs. Oxygen evolution reaction (OER) catalysts can alleviate carbon corrosion by introducing water electrolysis at a lower potential at the anode in fuel shortage. The mixture of hydrogen oxidation reaction (HOR) and unsupported OER catalyst not only reduces the electrolysis efficiency, but also influences the initial performance of the fuel cell. Herein, Ti4O7 supported IrOx is synthesized by utilizing the surfactant-assistant method and serves as reversal tolerant components in the anode. When the cell reverse time is less than 100 min, the cell voltage of the MEA added with IrOx/Ti4O7 has almost no attenuation. Besides, the MEA has a longer reversal time (530 min) than IrOx (75 min), showing an excellent reversal tolerance. The results of electron microscopy spectroscopy show that IrOx particles have a good dispersity on the surface of Ti4O7 and IrOx/Ti4O7 particles are uniformly dispersed on the anode catalytic layer. After the stability test, the Ti4O7 support has little decay, demonstrating a high electrochemical stability. IrOx/Ti4O7 with a high dispersity has a great potential to the application on the reversal tolerance anode of the fuel cell.

关键词： proton exchange membrane fuel cell (PEMFC)     fuel starvation     cell reverse     reversal tolerance anode     oxygen evolution reaction    

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Fabrication and performance of PEN SOFCs with proton-conducting electrolyte

ZHONG Li, LUO Jingli, Karl Chuang

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 40-44 doi: 10.1007/s11705-007-0008-6

摘要： A positive-electrolyte-negative (PEN) assembly solid oxide fuel cell (SOFC) with a thin electrolyte film for intermediate temperature operation was fabricated. Instead of the traditional screen-printing method, both anode and cathode catalysts were pressed simultaneously and formed with the fabrication of nano-composite electrolyte by press method. This design offered some advantageous configurations that diminished ohmic resistance between electrolyte and electrodes. It also increased the proton-conducting rate and improved the performance of SOFC due to the reduction of membrane thickness and good contact between electrolyte and electrodes. The fabricated PEN cell generated electricity between 600?C and 680?C using HS as fuel feed and air as oxidant. Maximum power densities 40 mW " cm and 130 mW " cm for the PEN configuration with a Mo-Ni-S-based composite anode, nano-composite electrolyte (LiSO+AlO) film and a NiO-based composite cathode were achieved at 600?C and 680?C, respectively.

关键词： proton-conducting     positive-electrolyte-negative     temperature operation     Mo-Ni-S-based composite     advantageous    

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Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1772-1781 doi: 10.1007/s11705-022-2197-4

摘要： Unlocking of the extremely inert C=O bond during electrochemical CO2 reduction demands subtle regulation on a key “resource”, protons, necessary for intermediate conversion but also readily trapped in water splitting, which is still challenging for developing efficient single-atom catalysts limited by their structural simplicity usually incompetent to handle this task. Incorporation of extra functional units should be viable. Herein, a proton deployment strategy is demonstrated via “atomic and nanostructured iron (A/N-Fe) pairs”, comprising atomically dispersed iron active centers spin-polarized by nanostructured iron carbide ferromagnets, to boost the critical protonation steps. The as-designed catalyst displays a broad window (300 mV) for CO selectivity > 90% (98% maximum), even outperforming numerous cutting-edge M–N–C systems. The well-placed control of proton dynamics by A/N-Fe can promote *COOH/*CO formation and simultaneously suppress H2 evolution, benefiting from the magnetic-proximity-induced exchange splitting (spin polarization) that properly adjusts energy levels of the Fe sites’ d-shells, and further those of the adsorbed intermediates’ antibonding molecular orbitals.

关键词： CO2 electrolysis     single-atom catalysts     spin polarization     proton dynamics     in situ IR spectroscopy     kinetic isotope effect    

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黄河下游新情况、新问题、新的治理措施

齐璞,孙赞盈,齐宏海

《中国工程科学》 2014年 第16卷 第8期   页码 64-68

摘要：

黄河下游的堤防是按照小浪底建库前千年洪水设防水位，加超高2.5 m或3 m设计，堤后淤背宽度百米，小浪底水库投入运用后下游宽河道段河槽下切2 米多，下游窄河段下切1 米多；在洪水不断减小的新形势下，防洪形势发生根本性变化，今后不存在大堤决口的可能。其合理的治理目标是，在中游完善以小浪底水库为中心的调水调沙体系，使更多泥沙由洪水输送；在下游进行双向河槽整治，稳定河槽，形成高效排洪输沙通道；控制河床不发生过渡冲刷，保证两岸引水，使洪水不漫滩；彻底解放黄河下游滩区和防洪中横河斜河等诸多问题，使黄河彻底由害河变为利河。

关键词： 小浪底水库     河道冲刷     双向整治     高效输沙     完善调沙体系    

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design of novel proton-pump inhibitors with reduced adverse effects

Xiaoyi Li, Hong Kang, Wensheng Liu, Sarita Singhal, Na Jiao, Yong Wang, Lixin Zhu, Ruixin Zhu

《医学前沿（英文）》 2019年 第13卷 第2期   页码 277-284 doi: 10.1007/s11684-018-0630-3

摘要： The development of new proton-pump inhibitors (PPIs) with less adverse effects by lowering the pKa values of nitrogen atoms in pyrimidine rings has been previously suggested by our group. In this work, we proposed that new PPIs should have the following features: (1) number of ring II= number of ring I+ 1; (2) preferably five, six, or seven-membered heteroatomic ring for stability; and (3) 1

关键词： proton-pump inhibitor     adverse effect     pharmacological mechanism     toxicological mechanism     pKa calculation    

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The source and transport of bioaerosols in the air: A review

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1336-8

摘要：

• Emission of microbe from local environments is a main source of bioaerosols.

关键词： Bioaerosols     Diffusion     Source identification     Biogeography    

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A cellphone-based colorimetric multi-channel sensor for water environmental monitoring

《环境科学与工程前沿（英文）》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1590-z

摘要：

● A cellphone-based colorimetric multi-channel sensor for in-field detection.

关键词： Colorimetric analysis     Multi-channel sensor     Cellphone     Water quality indexes     Environmental monitoring    

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Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 205-210 doi: 10.1007/s11709-007-0024-0

摘要： Based on the Backus-Gilbert inverse theory, the singular value decomposition (SVD) for general inverse matrices and the optimization algorithm are used to solve the channel friction inverse problem. The resolution and covariance friction inverse model in matrix form is developed to examine the reliability of solutions. Theoretical analyses demonstrate that the convergence rate of the general Newton optimization algorithm is in the second-order. The Wiggins method is also incorporated into the algorithm. Using the method, noise can be suppressed effectively, and the results are close to accurate solutions with proper control parameters. Also, the numerical stability can be improved.

关键词： singular     SVD     second-order     covariance     Theoretical    

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Ionic liquid modified Pt/C electrocatalysts for cathode application in proton exchange membrane fuel

Huixin Zhang, Jinying Liang, Bangwang Xia, Yang Li, Shangfeng Du

《化学科学与工程前沿（英文）》 2019年 第13卷 第4期   页码 695-701 doi: 10.1007/s11705-019-1838-8

摘要： The modification of Pt/C catalyst by using ionic liquids to improve their catalyst activities has been reported by many researchers, but their practical behavior in operating fuel cells is still unknown. In this work, we study the ionic liquid modified Pt/C nanoparticle catalysts within cathodes for proton exchange membrane fuel cells. The influence of the ionic liquid amount, adsorption times and dispersing solvents are investigated. The experiment results show the best performance enhancement is achieved through two-time surface modification with 2 wt-% ionic liquid solution. The mechanisms are explored with the attribution to the high oxygen solubility in the ionic liquid enabling an improved oxygen diffusion in micropores and to good hydrophobicity facilitating water expelling from the active sites in fuel cell operation.

关键词： ionic liquid     PEMFC     electrode     oxygen reduction reaction     electrocatalyst     adsorption    

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Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 364-375 doi: 10.1007/s11705-021-2052-z

摘要： The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells. In this paper, accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading. The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires, as well as their electrochemical performances in a single cell, are investigated. The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires. With increasing reduction temperature, the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40 °C. A mechanism of the Pt nanowires growth is proposed. The optimized Pt nanowires electrode exhibits a power density (based on electrochemical active surface area) 79% higher than conventional Pt/C one. The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词： Pt nanowires     morphology     structure control     in situ growth mechanism     proton exchange membrane fuel cells    

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Intercontinental transport of air pollution

Lin ZHANG,

《环境科学与工程前沿（英文）》 2010年 第4卷 第1期   页码 20-29 doi: 10.1007/s11783-010-0014-7

摘要： There is an increasing interest on the intercontinental transport of air pollution among the three main emission regions at northern mid-latitudes: North America, Europe, and East Asia. Air pollutants with sufficient long lifetime can be transported from one continent to another. Observations from ground sites, aircraft and satellites have demonstrated this intercontinental-scale transport of air pollutants in the free troposphere. Numerical models have been applied to understand the pathways of the transport and the impact of intercontinental pollution transport. This paper reviews current observational evidence and modeling studies of intercontinental transport of ozone and its precursors, and the resulting impacts on air quality.

关键词： intercontinental transport     ozone     air pollution    

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标题 作者 时间 类型 操作

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layerfor proton exchange membrane fuel cells

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

期刊论文

用于储能设备的一种新型高导电性和高选择性质子交换膜

Kang Huang, Shuhao Lin, Yu Xia, Yongsheng Xia, Feiyan Mu, Yuqin Lu, Hongyan Cao, Yixing Wang, Weihong Xing, Zhi Xu

期刊论文

西部铁路通道建设及政策措施

孙永福

期刊论文

光传送网中光监控通道信号Q值在线监测技术

唐勇,孙小菡,张明德,丁东

期刊论文

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

期刊论文

Fabrication and performance of PEN SOFCs with proton-conducting electrolyte

ZHONG Li, LUO Jingli, Karl Chuang

期刊论文

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

期刊论文

黄河下游新情况、新问题、新的治理措施

齐璞,孙赞盈,齐宏海

期刊论文

design of novel proton-pump inhibitors with reduced adverse effects

Xiaoyi Li, Hong Kang, Wensheng Liu, Sarita Singhal, Na Jiao, Yong Wang, Lixin Zhu, Ruixin Zhu

期刊论文

The source and transport of bioaerosols in the air: A review

期刊论文

A cellphone-based colorimetric multi-channel sensor for water environmental monitoring

期刊论文

Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

期刊论文

Ionic liquid modified Pt/C electrocatalysts for cathode application in proton exchange membrane fuel

Huixin Zhang, Jinying Liang, Bangwang Xia, Yang Li, Shangfeng Du

期刊论文

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

期刊论文

Intercontinental transport of air pollution

Lin ZHANG,

期刊论文