JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Ziyu Wang,Xuekun Jin,Fengjuan Chen,Xuanyu Kuang,Junyong Min,Haiming Duan,Junhua Li,Jianjun Chen
In proton exchange membrane fuel cells (PEMFC S ), a Pt-based catalyst has been plagued by activity and durability, making it difficult to implement in large-scale commercial applications. In this paper, a composite material formed by titanium dioxide and carbon black containing oxygen vacancies (TiO 2 (O V )-C) was used as a functional support to successfully load Pt nanoparticles (NP S ). The introduction of oxygen vacancies induces the formation of a connection between Pt and TiO 2 , which not only strengthens the fixation of Pt by the composite support but also optimizes the local charge density of Pt. Compared with Pt/C (0.842 V) and Pt/TiO 2 -C (0.841 V), the half-wave potential (E 1/2 ) of Pt/TiO 2 (O V )-C (0.862 V) is increased by 20 mV and 21 mV, respectively. After a long-term durability test, the E 1/2 of Pt/TiO 2 (O V )-C is only attenuated by 5 mV. In addition, the mass activity (MA) and specific activity (SA) decreased from 183.4 mA mg −1 and 0.565 mA cm −2 to 144.4 mA mg −1 and 0.483 mA cm −2 at 0.85 V, only decreasing by 21% and 17 %, showing good stability. X-ray photoelectron spectroscopies (XPS) and density functional theory (DFT) calculations show that the interaction between Pt and TiO 2 reduces the d-band center of Pt, thereby improving the desorption of intermediates *OH, which in turn promotes the activity of alkaline ORR . This study not only shows that O V plays a key role in the process of inducing interaction, but also deeply studies the influence of this interaction on the active site Pt, which provides more choices for the design of excellent multiphase catalysts.
研究领域:
材料科学
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催化化学
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能源科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Bin Hu,Yongqing Yang,Wei Cao,Xixi Wang,Chuan Zhou,Yiyang Mao,Lei Ge,Ran Ran,Wei Zhou
The high cost and unfavorable catalytic performance for oxygen reduction reaction (ORR) is one of the crucial obstacles that impede widely commercialization of proton-exchange membrane fuel cells (PEMFCs). Herein, we provide a novel, mass-producible ORR catalyst made of low-loading (10 wt%) Pt nanoparticles bound to patchy nitrogen-doped carbon (PNC) with uniformly dispersed FeN 4 sites (Pt/FeN 4 -PNC). The derived catalyst exhibits significantly improved catalytic activity and stability, obtaining a promising mass activity (MA) of 0.94 A mg pt −1 at 0.9 V (vs. RHE) with a negligible decay after 30,000 cycles accelerated durability test (ADT). In the fuel-cell assessment (under H 2 -Air conditions at 80 ℃), the Pt/FeN 4 -PNC and Pt/FeN 4 -PNC-10 g (scaled-up production) achieved peak power densities of 1.13 W cm −2 and 1.14 W cm −2 , respectively, and retained 88.5 % and 88.1 % of the initial values after 30,000 voltage cycles (0.60–0.95 V). The patchy structure of PNC substrate guarantees fast electron routes and resistance to corrosion. With the FeN 4 active sites in the PNC substrate, the oxygen molecules are concurrently reduced on the surfaces of the carbon substrate and Pt nanoparticles, thereby causing the ORR reaction zone on the catalyst layer to expand.
研究领域:
材料科学
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能源科学
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催化化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Bin Wen,Ruyin Ma,Gang Yang,Chongchao Li,Yike Huang,Linxin Zhong,Zhou Sha,Yifei Chen,Shuhan Cai,Daliang Guo,Jing Li,Qianyu Sun,Yinchao Xu,Tianzhong Yuan,Xin Zhang
To optimize the imbalance between the interfacial bonding and porosity properties of carbon paper (CP) caused by phenol formaldehyde resin (PF) impregnation, and therefore improve the performance of proton exchange membrane fuel cells (PEMFCs), a new approach through cellulose nanofibers grafted with methyl methacrylate (CNFM) as a modified reinforcement and pore-forming agent for PF is investigated. Through suppressing the methylene backbone fracture of CNFM-modified PF during its thermal depolymerization, the interfacial bonding between PF matrix carbon and carbon fibers is enhanced. Compared with unmodified CP, the in-plane resistivity of CNFM-modified CP is reduced by 35.78 %, while the connected porosity increases to 82.26 %, and more homogeneous pore size distribution (PSD) in the range of 20–40 μm is obtained for CNFM-modified CP. Besides, the tensile strength, flexural strength, and air permeability of CNFM-modified CP increase by 72.78 %, 298.4 %, and 103.97 %, respectively. In addition, CNFM-modified CP achieves the peak power density of PEMFCs to 701.81 mW·cm −2 , exhibiting 10.98 % improvement compared with commercial CP (632.39 mW·cm −2 ), evidently achieving an integral promotion of CP and comprehensive performance.
研究领域:
材料科学
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能源工程
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化学工程
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2023
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IF 7.2
Ying Wang,Zheng Xie,Weiqi Zhang,Huiyuan Liu,Qian Xu,Lindiwe Khotseng,Huaneng Su
A novel enhanced membrane electrode assembly (MEA) was successfully developed by incorporating a phosphoric acid (PA)-loaded Schiff base network (SNW)-type covalent organic framework (COF) as an additive to the catalyst layer (CL) to improve the performance of proton exchange membrane fuel cells (PEMFCs) under low humidity conditions. The unique network structure and PA-loaded H 3 PO 4 @SNW-1 material have excellent water management and proton transfer abilities. Direct use of this material as a CL additive can significantly enhance the performance of PEMFCs under varying humidification conditions. The optimization of the additive content , the impact of the anode/cathode modification, and the operating temperature of PEMFCs were studied using electrochemical characterization and single cell tests. The maximum power density of MEAs with 15 wt.% H 3 PO 4 @SNW-1 added to the anode CL at a normal operating temperature of 60 °C was 745 mW cm −2 and 690 mW cm −2 under full humidification (100% RH) and low humidification (21% RH), respectively, both of which were higher than that of conventional MEAs. Furthermore, preliminary durability test and 10-day intermittent operation demonstrate the potential of the proposed PEMFCs in actual operation in harsh environments.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
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2021
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IF 3.605
Kuixiao Wang,Yuanyuan Chu,Xiaoxiao Zhang,Ruochen Zhao,Xiaoyao Tan
Fe/NC single-atom catalysts containing atomically dispersed FeN4 moieties have exhibited encouraging activity comparable to that of Pt in aqueous acids and outstanding performance in practical proton exchange membrane fuel cells (PEMFCs). However, it is still challenging to design dispersive exposed Fe single atoms against agglomeration and tune Fe–Nx coordination configuration to maximize the intrinsic activity of each active site. Introducing a heteroatom, such as S, could effectively improve the activity of the Fe/NC catalyst. In this work, we synthesized a novel catalyst (denoted as Fe/SNC) by pyrolyzing Fe(SCN)3 and ZIF-8 precursors under media conditions. This in situ S-doped catalyst showed better activity (half-wave potential positively shifted by 25 mV) and stability (improved 18%) compared to the Fe/NC catalyst in 0.5M H2SO4 solution.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 6
·344
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IF 3.8
Fengshun Cheng,Yuchen Guo,Xinhong Liang,Fanqiushi Yue,Yichang Yan,Yang Li,Yuanzhi Zhu,Yanping He,Shangfeng Du
Ionic liquid modification for carbon-supported platinum (Pt/C) electrocatalysts to enhance their oxygen reduction reaction (ORR) activity has been well recognized. However, the research has only been reported on the low-Pt-loading Pt/C electrocatalysts, e.g., 20 wt%, while in practical applications, usually high-Pt-loading Pt/C electrocatalysts of 45–60 wt% are used. In this work, ionic liquid modification is systematically investigated for a Pt/C electrocatalyst with 60 wt% Pt loading for its ORR activity in the cathode in proton exchange membrane fuel cells (PEMFCs). Various adsorption amounts are studied on the catalyst surface. Different modification behavior is found. Mechanism exploration shows that the adsorption of ionic liquid mainly happens on the Pt electrocatalyst surface and in the micropores of the carbon support. The highest fuel cell power performance is achieved at an ionic liquid loading of 7 wt%, which is much higher than the 3 wt% reported for the low-Pt-loading Pt/C.
研究领域:
能源科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
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2024
·Vol. 12
·期 22
·13364-13373
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IF 10.7
Lei Huang,Qian Wang,Zimo Wang,Xi Sun,Jiayu Guan,Jifu Zheng,Shenghai Li,Suobo Zhang
Balancing phosphoric acid (PA) uptake with the dimensional stability of PA-doped membranes is a major challenge in the field of high-temperature proton-exchange membranes. Crosslinking is a common method to solve this problem. However, the construction of conventional crosslinked membranes usually involves a two-step process in which linear polymers are first prepared, followed by the addition of crosslinkers during film formation to generate crosslinked networks. This further complicates the preparation process of crosslinked membranes. In this study, superacid-catalyzed Friedel–Crafts polyhydroxyalkylation was employed to fabricate knitted-network membranes with a high density of alkaline groups in a single step, significantly simplifying the preparation process of crosslinked membranes. Compared with commercial OPBI membrane, the knitted-network membranes exhibited significantly improved mechanical properties; moreover, PA retention was significantly improved, attributable to the formation of three-dimensional crosslinked networks and ultra-microporous structures within the membranes. Additionally, the PA-doped knitted-network membranes exhibited a good conductivity of 186 mS cm−1 at 200 °C and a high peak power density of 850 mW cm−2 at 200 °C without backpressure and humidification. This study is the first to report this in situ polymerization method in which the same precursor monomer is adopted in the subsequent polymerization process to form a crosslinked network. The proposed strategy exhibits significant application potential in the field of high-temperature proton-exchange membrane fuel cells.
研究领域:
化学工程
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材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2025
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IF 7.9
Yong Yu,Feng Ji,Shaojie Gao,Chengwei Deng,Bowen Zheng,Weiwei Cai
High-temperature proton exchange membrane fuel cells (HT-PEMFCs) exhibit strong tolerance to impurities in hydrogen, which enhances their potential for practical applications. However, the efficiency of gas, proton, and electron electrocatalytic interfaces remains suboptimal, leading to sluggish cathode reaction kinetics and significantly reducing platinum (Pt) utilization. In this study, quaternary ammonium-functionalized polybenzimidazole (QAPBI), where the quaternary ammonium groups form strong ion pair interactions with phosphate, is employed as a bifunctional ionomer in the cathode catalyst layer (CL). This modification facilitates the regulation of phosphate (PA) distribution within the cathode CL and simultaneously improves proton conduction efficiency. Consequently, well-structured three-phase interfaces are effectively established, and the adsorption of PA onto the catalyst surface is minimized, further enhancing Pt utilization. More importantly, the rapid adsorption of PA onto QAPBI reduces the migration and loss of PA during fuel cell operation, thereby enhancing long-term durability. As a result, the peak power density (PPD) of the QAPBI-based HT-PEMFC is increased by 42 % compared to conventional PTFE-based designs, with a corresponding improvement in durability of 37.5 %.
研究领域:
材料科学
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能源技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Zhuojie Xiao,Yangcheng Jiang,Hao Wu,Huichi Zhong,Huiyu Song,Ali Abdelhafiz,Jianhuang Zeng
Proton exchange membrane fuel cell is a viable technology for clean energy production, however developing a cost-effective and highly efficient catalyst for oxygen reduction reaction (ORR) is a challenge to overcome. A promising strategy is alloying Pt with transition metals where synergistic effects and strain induced on Pt adatoms can lead to unprecedent activity. Controlling alloy composition and particle structure are highly complex as alloying order increases. Herein, we report a facile and simple one-pot synthesis method, to synthesize carbon-supported PtCuFe nanoparticles surpassing DOE technical requirement of ORR catalyst for PEMFC application. After voltammetric dealloying, a Pt-rich shell is exposed on the surface of the PtCuFe nanoparticles. The elemental composition and electronic environment of PtCuFe nanoparticles are characterized using high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The condition of dealloying affects catalytic activity for ORR. Dissolution of non-noble metals exhibits significant improvement of PtCuFe ORR activity, as well as, an enhancement in their stability. D -Pt 2 CuFe/C-150 catalyst shows an ORR mass activity of 0.99 A mg −1 Pt at 0.90 V vs. RHE, records 2.9 fold enhancement over state-of-the-art commercial TKK catalyst. Furthermore, D -Pt 1 CuFe/C-150 exhibits prolonged stability, with a mass activity loss of only 7.6% after 5000 durability cycles, whereas TKK catalyst suffers for a 29.4% loss under the same conditions.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2021
·Vol. 11
·期 4
·2010-2019
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IF 3.361
Ke Zhou,Tianya Li,Yufen Han,Jihao Wang,Jia Chen,Kejian Wang
The gas diffusion layer (GDL) is an important component in the proton exchange membrane fuel cell (PEMFC), and the main function of GDL is to transfer water and gas. This paper explores the effect of the gradient hydrophobicity of GDL on the proton exchange membrane fuel cell (PEMFC). The gradient GDL design uses two microporous layers (MPL). First, polytetrafluoroethylene (PTFE) : carbon black in MPL near the carbon paper side was fixed at 3 : 7, and then the content of PTFE : carbon black in MPL near the catalyst layer (CL) was set to 3 : 7, 2 : 8 and 1 : 9. Second, the fixed PTFE : carbon black in MPL near the carbon paper side was 2 : 8, and the PTFE : carbon black in MPL near CL was 2 : 8 and 1 : 9. We found that, when near the carbon paper side and PTFE : carbon black = 3 : 7, GDL can obtain good cell performance through gradient hydrophobic treatment. Moreover, when near the carbon paper side and PTFE : carbon black = 2 : 8, the cell performance did not change much after GDL gradient hydrophobic treatment. We found that when GDL is subjected to a gradient hydrophobic treatment, the content of PTFE and carbon black must be rationally allocated to obtain good water management capabilities.
研究领域:
能源科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2018
·Vol. 11
·期 4
·642
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IF 2.467
Kang Fu,Yang Wang,Ying Qian,Linchang Mao,Junhong Jin,Shenglin Yang,Guang Li
The potential of graphene–multi-walled-carbon nanotube (G-M) hybrids prepared by the one-pot modified Hummers method followed by thermal annealing has been demonstrated by employing one as an electrocatalyst support for oxygen reduction reaction (ORR). N doping effectively modified the electronic structure of the G-M hybrid support, which was beneficial for the uniform distribution of Pt nanoparticles, and ORR activities were further improved. The newly prepared Pt/N-G-M catalyst demonstrated higher electrochemical activity than Pt/G-M and Pt/G catalysts. Even compared with commercial 20 wt % Pt/C (JM20), Pt/N-G-M delivered a better half-wave potential and mass activity. In terms of the durability test, Pt/N-G-M maintained 72.7% of its initial electrochemical active surface area (ECSA) after 2000 repeated potential cycles between 0 and 1.2 V in acidic media in relation to the 44.4% retention for JM20. Moreover, the half-wave potential for Pt/N-G-M showed only a minimal change, significantly superior to the 139 mV of loss for JM20. It is expected that Pt/N-G-M can be the potential candidate as a highly efficient and durable catalyst if utilized in proton exchange membrane fuel cells (PEMFCs).Keywords:oxygen reduction reaction;graphene–multi-walled carbon nanotubes;N doping;proton exchange membrane fuel cells
研究领域:
材料科学
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电化学
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纳米技术
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能源材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2022
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IF 10.53
Donglin He,Guoliang Liu,Ailian Wang,Wenxi Ji,Jianing Wu,Haolin Tang,Weiran Lin,Taoyi Zhang,Haining Zhang
Although phosphoric acid doped polybenzimidazole has been proposed as promising high-temperature proton exchange membrane, the poor absorption and immobilization ability of phosphoric acid in the membrane hinders its long-term stability. In this work, high-temperature proton exchange membranes with high phosphoric acid uptake and retention ability are fabricated thorough solvent casting of an alkali-free quaternized poly(4,4’-diphenylether-5,5’-bibenzimidazole) (OPBI), followed by doping of phosphoric acid. The optimized membrane with quaternization degree of 50% possesses a high acid-doping-level of 18.8 and an anhydrous conductivity of 85 mS cm −1 at 160 °C. Stability tests reveal that anhydrous proton conductivity remains unchanged during continuous 100 h treatment at 160 °C and it remains 91.7% of its initial value after 100 h treatment at 80 °C under 40% RH. The thus-assembled single cell exhibits the maximum power density values of 0.355, 0.495, and 0.584 Wcm −2 at 160 °C under back pressure of 0, 100, and 200 kPa using hydrogen as fuel and air as oxidant gas.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）