ELECTROCHIMICA ACTA
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2022
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IF 7.336
Geng Cheng,Zhen Li,Erli Qu,Shan Ren,Dongmei Han,Min Xiao,Shuanjin Wang,Yuezhong Meng
It's of significant importance for the development of proton exchange membranes with low phosphoric acid (PA) uptake, high proton conductivity, better proton conduction stability and low production-costs for high temperature proton exchange membrane fuel cells (HT-PEMFCs). Featured with variable structure and diversified functionality, porous organic networks are newly emerged filler materials for polyelectrolytes in energy conversion field. In this work, a typical Schiff-base type porous polymeric network (SNW-1) with abundant N H sites was synthesized and blended with ether-type polybenzimidazole (PBI) for the first time. The thermal and chemical stability of the as-prepared composite membranes completely satisfy the practical requirements of HT-PEMFCs. The constructed consecutive proton conduction channels endow the composite membranes higher proton conductivity with low PA uptake. When the doping content of SNW-1 reached 30%, the PBI/30%-SNW-1 membrane showed much higher proton conductivity with lower PA uptake (114.0 mS cm −1 , 175.0%) comparing with those of the pristine PBI (67.3 mS cm −1 , 270.0%) at 160 °C. The PBI/ x %-SNW-1 membranes also exhibited better proton conduction stability. After 30 h of long-time evaluation at 140 °C, PBI/30%-SNW-1 composite membrane gives only an 8.47% decay of proton conductivity, which is lower than that of the pristine PBI (12.84%). The preparation procedure of PBI/ x %-SNW-1 composite membranes is simple, which provides a potential pathway for the development of high-performance proton exchange membrane for HT-PEMFCs.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 93
·91068-91076
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IF 3.289
Guohua Sun,Kefei Han,Jinghua Yu,Hong Zhu,Zhongming Wang
As an efficient, inexpensive, readily accessible monomer of the polybenzimidazole (PBI) copolymer, the 4,4′-[(4,4′-bipyridine)-2,6-diyl]dibenzoic acid (BPY) containing bipyridine unit was firstly used to synthesize a series of novel non-planar PBI copolymers (BPY–PBI-x) by regulating the ratio with 2,6-pyridinedicarboxylic acid under microwave-assisted conditions. The copolymers exhibit superior solubility in aprotic solvents such as N,N-dimethylacetamide, N,N-dimethylformamide and dimethylsulfoxide than general PBI, and the corresponding BPY–PBI-x serial membranes were prepared by a solution casting method. All the membranes have been characterized by thermal stability, a tension test, scanning electron microscopy, PA-doping ability and swelling ratio, proton conductivity, and a Fenton test. The membranes exhibit excellent comprehensive properties containing high proton conductivity and long lifetime. The conductivity of the doping levels of the BPY–PBI-100% membrane with the highest doping level (342.7%) reaches 78.6 mS cm−1 at 160 °C. The high proton conductivity is attributed to the increase in N atoms of the proton acceptor from the bipyridine monomer and the enhancement of free volume from the existence of a bulky stereostructure BPY unit. The long lifetime is due to the fact that the pyridine unit can quench radicals by the formation of pyridine-N-oxide. The unique anti-oxidation mechanism of the BPY–PBI-x serial membranes, which firstly was pointed out for the application of pyridine heterocyclic rings in HT-PEMs, provides new insights for novel anti-oxidation membrane design. In short, 3-fold objectives, namely, (I) soluble PBI, (II) higher proton conductivity PBI, and (III) anti-oxidative PBI, were achieved in this paper.
研究领域:
材料科学
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化学工程
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
At Van Nguyen,Tai Thien Huynh,Hau Quoc Pham,Vi Thuy Thi Phan,Son Truong Nguyen,Van Thi Thanh Ho
Late transition metal doped TiO 2 has been exploited for generating efficient catalyst support by enhancing electrical conductivity and modifying properties of TiO 2 . The Ti 0·7 Ir 0·3 O 2 nanorod (NRs), a novel catalyst support for Pt nanoparticles , was prepared for the first time via single-step hydrothermal process at low temperature using IrCl 3 ·3H 2 O and TiCl 4 as starting materials. We found that the Ti 0·7 Ir 0·3 O 2 NRs with 70–80 nm in length and 25–30 nm in width is successful prepared at 210 °C for 12 h without utilizing surfactants or stabilizers . In addition, the Ti 0·7 Ir 0·3 O 2 NRs was presented principally as a single-phase solid with the TiO 2 is in the rutile form with high crystallinity without using further treatment after synthesis. More importantly, we found that the Ti 0·7 Ir 0·3 O 2 NRs possesses high electrical conductivity (0.028 S cm −1 ) dealing the intrinsically non-conducted drawback of TiO 2 . The Pt nanoparticles were then deposited on the support of Ti 0·7 Ir 0·3 O 2 NRs via chemical reduction method. The properties of 20 wt % Pt/Ti 0·7 Ir 0·3 O 2 NRs electrocatalyst were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), the cyclic voltammetry (CV). The uniformly distributed small Pt nanoparticles (3–4 nm diameter) were well adhered to the Ti 0·7 Ir 0·3 O 2 NRs. The electrochemically active surface area (ECSA) of 20 wt % Pt/Ti 0·7 Ir 0·3 O 2 NRs was higher than that of the commercial 20 wt % Pt/C (E-TEK) due to the small size and good dispersion of Pt nanoparticles on the surface of Ti 0·7 Ir 0·3 O 2 NRs. Moreover, the ECSA value of the Pt/Ti 0·7 Ir 0·3 O 2 NRs retained up to 88% after 2000 cycles of cyclic voltammetry, suggesting the high stability of catalyst resulted from strong metal support interaction (SMSI) of Titania-based materials with the noble metals. More importantly, the onset potential of Pt/Ti 0·7 Ir 0·3 O 2 NRs catalyst towards oxygen reduction reaction is more positive (∼80 mV) compared to commercial Pt/C, indicating the high catalytic activity of the Pt/Ti 0·7 Ir 0·3 O 2 NRs catalyst. The results of this research suggested that novel Ti 0·7 Ir 0·3 O 2 NRs could be applied as promising robust non-carbon support for Pt. This research also creates a preliminary step for investigating systematically promising Iridium doped Titania materials.
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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催化
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燃料电池
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2019
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IF 8.456
Lin Li,Shuiyun Shen,Guanghua Wei,Xiaolin Li,Kun Yang,Qi Feng,Junliang Zhang
There remain great challenges in exploring cost-effective and highly efficient non-noble metal electrocatalysts to catalyze the oxygen reduction reaction (ORR) of proton exchange membrane fuel cells (PEMFCs). Also, a further validation on their performances under a fuel cell operating condition draws sustained attention. Herein, we report a comprehensive investigation on the ORR performances of a series of pyrolyzed Fe–N–C composites that use phenanthrolene as the nitrogen precursor, and the effects of carbon supports, transition metal precursors, and annealing temperatures are examined in detail. Electrochemical measurements combined with different physicochemical characterizations are employed to clarify the function of critical structures including the specific surface area, microstructure, nitrogen content, nitrogen type, and corresponding proportion on their ORR and fuel cell performances. It demonstrates a half-wave potential of 0.79 V and almost a four-electron pathway. When using the as-optimized Fe–N–C composite as the cathode catalyst of a PEMFC, the maximum power density reaches as high as 540 mW cm–2.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2024
·Vol. 110
·期 1
·103-117
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IF 2.3
Chen Gaokui,Shen Qiuwan,Zhang Xin,Zhao Tianyun,Huang Naibao,Li Shian
Abstract Methanol steam reforming (MSR) is considered as an effective way to provide on-line hydrogen production technology for fuel cell applications, and perovskite catalyst is considered as an efficient and potential catalyst for this technology. A series of La 1-x M x Co 0.5 Ni 0.5 O 3 perovskite catalysts doped with yttrium(Y) and cerium(Ce) at A site were prepared by sol-gel method. The catalysts were characterized by SEM, EDS, BET, XPS and XRD techniques. The results of XRD, SEM and BET show that the main phase of the catalyst is perovskite when a small amount of Y or Ce is doped. However, with the increase of Y and Ce doping levels, some other new phases appeared. The appearance of the new phase of yttrium oxide promotes the richer pore structure of the catalyst, increases the pore volume and pore diameter, and enhances the active catalytic sites. More importantly, it also promotes the increase of the specific surface area, allowing the active component particles to maintain a very uniform dispersion state, effectively preventing the aggregation of active components and improving the catalytic activity. From the XPS results of Y-doped catalyst with x of 0.9, Y-O bonds belonging to Y 2 O 3 can be observed, the presence of yttrium carbonate species can promote the formation of oxygen vacancies, thereby accelerating the catalytic reaction and enhancing the catalytic performance. After multiple cycles of start-stop stability experiments, the results showed that the CO selectivity of the gas product was 1.8% and remained unchanged without significant fluctuations. The novel yttrium-doped catalyst with x of 0.9 developed in this study is a potential catalyst which can directly provide hydrogen-rich source for HT-PEMFCs applications. Graphical Abstract The novel La 0.1 Y 0.9 Co 0.5 Ni 0.5 O 3 catalyst, with high specific surface area and well-developed pore structure, exhibits excellent low CO selectivity and stability in the MSR process, which can be a promising catalyst for directly providing hydrogen-rich source for HT-PEMFCs applications.
研究领域:
化学工程
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催化材料
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能源科学
✓ 已验证
DOI
高影响因子
Nature Communications
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2024
·Vol. 15
·期 1
·1-11
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IF 14.7
Long Daojun,Liu Yongduo,Ping Xinyu,Chen Fadong,Tao Xiongxin,Xie Zhenyang,Wang Minjian,Wang Meng,Li Li,Guo Lin,Chen Siguo,Wei Zidong
The serious problem of carbon monoxide (CO) poisoning on the surface of Pt-based catalysts has long constrained the commercialization of proton exchange membrane fuel cells (PEMFCs). Regeneration of Pt sites by maintaining CO scavenging ability through precise construction of the surface and interface structure of the catalyst is the key to obtaining high-performance CO-resistant catalysts. Here, we used molybdenum carbide (MoC x ) as the support for Pt and introduced Ru single atoms (SA-Ru) at the Pt-MoC x interface to jointly decrease the CO adsorption strength on Pt. More importantly, the MoC x and SA-Ru are immune to CO poisoning, which continuously assists in the oxidation of adsorbed CO by generating oxygen species from water dissociation. These two effects combine to confer this anode catalyst (SA-Ru@Pt/MoC x ) remarkable CO tolerance and the ability to operate stably in fuel cell with high CO concentration (power output 85.5 mW cm −2 @20,000 ppm CO + H 2 – O 2 ), making it possible to directly use the cheap reformed hydrogen as the fuel for PEMFCs.
研究领域:
材料科学
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电化学
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催化
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能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
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2025
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IF 7.5
Balamurali Ravichandran,Naresh Narayanan,Huiyuan Liu,Weiqi Zhang,Narayanamoorthy Bhuvanendran,Huaneng Su
Intensified electrochemical corrosion under high-temperature and phosphoric acid conditions poses a significant challenge to the catalysts in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). Herein, a S, P-doped hierarchical porous carbon nitride (S, P-HCN) supported PtCo alloy catalyst was developed to address this issue. The multilayered porous structure of S, P-HCN ensures high metal dispersion, a large specific surface area, and enhanced mass transfer. The PtCo/S, P-HCN catalyst exhibits remarkable performance, with specific activity (1.27 mA cm Pt -2 at 0.80 V), mass activity (0.51 mA µg Pt -1 at 0.80 V), and electrochemical active surface area (ECSA) (39.9 m 2 g -1 Pt ), surpassing commercial 20 % Pt/C by 2–3 times. Durability tests over 5000 potential cycles reveal excellent retention of mass activity (84 %) and specific activity (83.2 %) at 0.80 V, with only a minor 14 mV shift in half-wave potential. This enhancement stems from the synergistic effects between PtCo alloy nanoparticles and S, P-HCN, which modulate Pt- electronic structure, strengthen metal-support interactions, and boost catalytic efficiency. Single-cell HT-PEMFC studies demonstrate a peak power density of 377.4 mW cm −2 for PtCo/S, P-HCN, comparable to commercial Pt/C (398 mW cm −2 ), with reduced voltage degradation at low current densities. This work presents a promising approach for improving cathode materials and advancing HT-PEMFC performance.
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2023
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IF 9.1
Qingting Liu,Zhiwei Ling,Xiaohe Wang,Xudong Fu,Wenzhuo Wu,Chunyong Xiong,Bei Wang,Rong Zhang,Xiao Li,Feng Zhao,Xujin Bao,Shengfei Hu,Jun Yang
To prevent phosphoric acid (PA) from leaching and harming traditional polybenzimidazole-based proton exchange membranes , polyethyleneimine-confined halloysite nanotubes (PEI@HNTs) were embedded in poly (2,5-benzimidazole) membranes to construct rich ion pairs that stably conducted protons. With the aid of supercritical carbon dioxide , PEI oligomers with basic groups were confined in HNTs. Then, through in-situ synthesis, highly-dispersed PEI@HNT enhanced the mechanical stability of composite membranes , whose basicity improved the absorption and retention capacity of PA. The PEI@HNTs/ABPBI composite membrane exhibited excellent mechanical strength and electrical performance over a temperature range of 40–180 °C. The through-plane proton conductivity of the 5%PEI@HNTs/ABPBI composite membrane was 0.061 S cm −1 at 98% relative humidity and 90 °C and 0.049 S cm −1 under anhydrous conditions at 180 °C. This performance was attributed to strong hydrogen bonding between PEI and PA, as well as the excellent retention of bound water within the HNTs. The peak power density of PA-doped 5%PEI@HNTs/ABPBI composite membrane reached 0.235 W cm −2 and 0.418 W cm −2 at 120 °C and 180 °C under anhydrous conditions, respectively, which were 1.68 and 1.96 times higher than those obtained with the pristine PA-ABPBI membrane. These results highlight the potential of this composite membrane for applications requiring a wide temperature range.
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
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2023
·Vol. 170
·期 8
·084510
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IF 3.9
Jinyi He,Tianhui Li,Yingying Liu,Ao Wang,Wenxing Jiang,Chengwei Deng,Junbo Hou,Xiaodong Zhuang,Junliang Zhang,Changchun Ke
Poly[2,2-(m-phenylene)−5,5-bibenzimidazole] (m-PBI), the most studied PBI, is close to practical application, however, the high cost of m-PBI restricts its application for HT-PEMFCs. The cost can be reduced by 85% if the low cost & high impurity industrial DAB can be used to synthesize m-PBI after pre-treatment. Herein, we study the influence of impurities in industrial 3,3'-diaminobenzidine (DAB) on the synthesis of polybenzimidazole (PBI), and the possibility of the synthesis of m-PBI based on purified low cost & high impurity industrial DAB. It is shown that impurities would reduce the molecular weight and thermal stability of PBI, and mechanical strength and oxidation stability of the according PBI and H3PO4/PBI membranes. Using industrial DAB (94.40%) without any treatment as a reactant, the molecular weight of the obtained PBI is too low to prepare a membrane. A simple method of purifying low cost & high impurity industrial DAB is proposed, by dissolution and recrystallization using the absorption effect of carbon powder. It is proven that the performances of PBI synthesized using purified DAB are near to the PBI synthesized using high-purity DAB. The peak power density of HT-PEMFC based on PBI from purified industrial DAB reached 426 mW cm−2 at 180 °C.
研究领域:
材料科学
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化学工程
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能源技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 15
·7145-7157
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IF 11.301
Jinling Xue,Yinshi Li,Jue Hu
It remains a major challenge to develop a facile method to prepare non-noble metal electrocatalysts with high activity and durability to drive the sluggish oxygen reduction reaction (ORR) for proton exchange membrane fuel cells (PEMFCs). Herein, a highly efficient bimetallic Zn/Fe@N-doped hierarchical porous carbon (Zn/Fe–N–C) catalyst derived from ZIF-8 and hemin (host–guest) was firstly reported by one-step thermal treatment. Fe2+ spatially separated by using the hemin guest in the ZIF-8 framework and hydrocarbon-branched chains form rich Fe–Nx active sites, and the evaporation of Zn2+ generates a highly porous structure in the Zn/Fe–N–C catalysts. Benefitting from this unique structure and composition, the resulting Zn/Fe2–N–C catalyst exhibits excellent ORR activities in both 0.1 M KOH (onset potential, Eonset = 1.08 V, and half-wave potential, E1/2 = 0.86 V vs. RHE) and 0.5 M H2SO4 media (Eonset = 1.04 V and E1/2 = 0.81 V), which are even comparable to those of the commercial Pt/C catalyst, and ranks among the top reported electrocatalysts. In addition, it also has outstanding long-term durability and good methanol resistance, much better than those of Pt/C in both acidic and alkaline media, which makes it one of the best non-noble alternatives of Pt-based catalysts for ORR electrocatalysis. This work highlights the potential to rationally design and fabricate high-performance ORR catalysts for fuel cell applications.
研究领域:
材料科学
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电化学
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催化
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能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）