ACS Applied Energy Materials
·
2021
·
IF 6.024
Feng Zhang,Dongqing Zhang,Wenqi Liu,Jiyuan Miao,Xiaojin Li
Developing a feasible method to massively fabricate low-cost and efficient oxygen reduction reaction (ORR) catalysts is highly anticipated to the commercialization of fuel cells. In this work, N atoms were doped into inert sp2 configuration to alter the spin and charge distribution in the carbon matrix. The Pt/H2–N–C catalyst was successfully prepared by embedding ultralow Pt nanoparticles on N-based carbon. Results indicated that the protonated N-groups at edge sites efficiently regulated the absorption of the PtCl62– anion and widely limited the migration of Pt species at 1000 °C. The acquired Pt/H2–N–C electrocatalyst exhibited high ORR performance in the acidic electrolyte. The high-temperature proton exchange membrane fuel cell (HT-PEMFC) measurement illustrated that the open-circuit voltage and power density of the Pt/H2–N–C catalyst were higher than those of the commercial 20% Pt/C at 150 °C. This work provided a facile strategy to obtain efficient and low-cost Pt catalysts for ORR and HT-PEMFCs.
研究领域:
材料科学
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化学工程
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2010
·
IF 3.203
Songjun Zeng,Lei Ye,Sijia Yan,Guoliang Wu,Yuanqin Xiong,Weijian Xu
Amphibious proton exchange membranes (PEMs) which could be used under both wet and dry conditions were prepared by sol–gel method in this work. Those novel hybrid PEMs were constructed by three parts: (1) polysiloxane with two basic sites (–NH– on the pendant and N– in the triazole); (2) H 3 PO 4 as the proton source; (3) poly(vinyl alcohol) (PVA) which had good film-forming capacity and ability to anchor the H 3 PO 4 under wet conditions. The resulting hybrid membranes were thermally stabilized up to 200 °C. A matrix-change between polysiloxane and PVA could be observed at a high PVA doping level. The proton conducting property of these membranes was investigated under both hydrous and anhydrous conditions. From 25 to 120 °C, the non-soaked and soaked (soaked in the water) membranes showed the proton conductivity of 19–68 and 9–31 mS cm −1 at 100% relative humidity (RH), respectively. Under completely dry conditions, the proton conductivity of these membranes showed large dependence on the temperature and the proton conductivity of 4.7–21 mS cm −1 was achieved at 150 °C for these membranes. The excellent performance of these hybrid membranes under both wet and dry conditions demonstrated that they have potential use as electrolytes in polymer electrolyte membrane fuel cells (PEMFCs) operating either in a watery or in a water-free environment and so called “amphibious” proton conducting membranes.
研究领域:
材料科学
·
高分子化学
·
能源材料
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燃料电池
·
纳米科技
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2022
·Vol. 29
·期 5
·e202202858
·
IF 5.02
Yongsheng Wang,Xinyu Wang,Hailong Wei,Junling Huang,Likun Yin,Wei Zhu,Zhongbin Zhuang
Graphical This work reports the homogeneous incorporation of Co into the FeP host to promote both activity and stability of HER for the PEMWE application and demonstrates the probable origin of the high performance by ex situ experiments. Metal phosphides are promising noble metal-free electrocatalysts for hydrogen evolution reaction (HER), but they usually suffer from inferior stability and thus are far from the device applications. We reported a facile and controllable synthetic method to prepare metal-incorporated M-FeP nanoparticles (M=Cr, Mn, Co, Fe, Ni, Cu, and Mo) with the guide of the density functional theory (DFT). The evaluated HER activity sequence was consistent with the DFT predictions, and cobalt was revealed to be the appropriate dopant. With the optimization of the Co/Fe ratio, the Fe 0.67 Co 0.33 P/C only required overpotentials of 67 mV and 129 mV to obtain the cathodic current density of 10 and 100 mA cm −2, respectively. It maintained the initial activity in the 10 h stability test, surpassing the other Co-FeP/C catalysts. Ex situ experiments demonstrated that the decreased element leaching and the increased surface phosphide content contributed to the high stability of the Fe 0.67 Co 0.33 P/C. A proton exchange membrane water electrolyzer was assembled using the Fe 0.67 Co 0.33 P/C as the cathodic catalyst. It showed a current density of 0.8 A cm −2 at the applied voltage of 2.0 V and retained the initial activity in the 1000 cycles’ stability test, suggesting the potential application of the catalysts.
研究领域:
电化学
·
材料科学
·
催化
·
可再生能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 38
·46737
·
IF 1.901
Xiangze Cheng,Huaiyang Jin,Chunhui Shen,Shanjun Gao,Jiang Wang,Xi Zhu
A polyphosphoric acid functionalized proton exchange membrane (PEM) was prepared by a ring opening reaction using the epoxycyclohexylethyltrimethoxysilane (EHTMS) and amino trimethylene phosphonic acid (ATMP) as raw materials and was modified by poly(vinylidene fluoride)–hexafluoro propylene (PVDF-HFP). The structure of the membranes was characterized by Fourier transform infrared and scanning electron microscopy. The X-ray photoelectron spectroscopy explores the content of the elements in the membrane related to the ion exchange capacity value. The membranes’ properties including water uptake, swelling ratio, proton conductivity, and hydrolysis stability were studied. Performance tests show that when ATMP/EHTMS = 1/5, conductivity of the PVDF-HFP modified PEMs increased from 0.83 × 10 −4 S cm −1 at 20 °C to 9.53 × 10 −3 S cm −1 at 160 °C, the swelling ratio of membranes decreased from 2.71% to 2.13%. The results indicate that the introduction of F atoms is beneficial to increase the proton conductivity and the dimensional stability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46737.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 44
·期 8
·2300007
·
IF 4.6
Wenjie Wang,Guitian Tai,Yixuan Li,Junqi Sun
Proton exchange membranes (PEMs) with excellent durability and working stability are important for PEM fuel cells with extended service life and enhanced reliability. In this study, highly elastic, healable, and durable electrolyte membranes are fabricated by the complexation of poly(urea–urethane), ionic liquids (ILs), and MXene nanosheets (denoted as PU–IL–MX). The resulting PU–IL–MX electrolyte membranes have a tensile strength of ≈3.86 MPa and a strain at break of ≈281.89%. The PU–IL–MX electrolyte membranes can act as high temperature PEMs to conduct protons under an anhydrous condition of the temperatures above 100 °C. Importantly, the ultrahigh density of hydrogen-bond-cross-linked network renders PU–IL–MX membranes excellent IL retention properties. The membranes can maintain more than ≈98% of their original weight and show no decline of proton conductivity after being placed under highly humid conditions of ≈80 °C and relative humidity of ≈85% for 10 days. Moreover, due to the reversibility of hydrogen bonds, the membranes can heal damage under the working conditions of fuel cells to restore their original mechanical properties, proton conductivities, and cell performances.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Yu Zhang,Junming Dai,Hua Lai,Yinhua Wan,Young Moo Lee,Yongbing Zhuang
The development of proton exchange membrane fuel cells (PEMFCs) that operate over a wide temperature range without additional humidification systems remains challenging. In this work, wide-temperature-range proton exchange membranes (PEMs) were constructed from novel Tröger’s base (TB)-based intrinsically microporous copolyimides (co-PIs) finely adjusted by incorporating crown ether units into chain backbones. Owing to the strong siphoning effect of existing microporosity and hydrogen bonds or the acid–base interactions of crown ether and TB units with phosphoric acid (PA) and/or H2O, the PA-doped co-PI membrane electrode assemblies (MEAs) can easily operate stably from 30 to 160 °C under H2/air conditions even without any external humidifiers. Regarding its single-cell performance, PI-TB-N30C achieved maximum power densities of 250 and 361 mW cm–2 at 80 and 160 °C, respectively, under anhydrous conditions. In addition, PA-doped co-PI MEA can accomplish long-term stable operation under low or high temperatures for 120 h. The structural architectures for PEMs based on finely adjusted microporous co-PIs extend beyond the current capabilities of existing PEMFCs.
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
POLYMER TESTING
·
2021
·
IF 4.282
Haochuan Luo
An effective method to prepare crosslinked polybenzimidazole (PBI) via [2 + 3] Huisgen cycloadditions has been proposed. Propargyl modified PBI (PBI-PG) has been synthesized firstly. In the presence of diazido crosslinkers, PBI-PG can be thermally crosslinked by [2 + 3] Huisgen cycloadditions. Evidences from 1 H NMR and ATR spectra imply a small amount of grafting alkenyl structures on PBI-PG. The grafting alkenyl structures provide another crosslinking mechanism named as alkyne-alkene crosslink. The alkyne-alkene crosslink is highly efficient under heat to form crosslinking networks which display toughness, low tensile strengths, and large swelling ratios in phosphoric acid (PA) solutions. Influences of rigidities and chain lengths of crosslinkers on performances of crosslinked PBIs have been investigated. PBIs crosslinked by rigid crosslinkers behave as brittle materials while that crosslinked by flexible crosslinkers behave as tough materials. Addition of crosslinkers leads to decreased gel fractions but improved tensile strengths, which is attributed to competition results of crosslinking and plasticizing effects. PBI-R2-20, which is crosslinked by a long rigid crosslinker, exhibits the highest tensile strength of 102.33 MPa, which is 66.34 MPa higher than that of PBI-PG. With even lower PA uptakes, PBIs crosslinked by rigid crosslinkers display more thermally stable and higher conductivities than that crosslinked by flexible crosslinkers. After doping in 12 mol/L PA solution, PBI-R2-20, with an acid uptake of 163 wt%, displays the highest tensile strength of 8.1 MPa and the most thermally stable and the highest conductivity which reaches a maximum of 2.30 × 10 −2 S cm −1 at 188 °C among all crosslinked membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Xiaocan Zhang,Jiashu Long,Mengxin Wang,Yiran Liu,Huixiao Ma
Blending metal-organic frameworks to optimize proton transport pathways is one of the strategies to improve the proton conductivity of proton exchange membranes (PEM). In this paper, amino-sulfonic acid bifunctionalized UiO-66 (NUS) by one-pot solvothermal method is synthesized, and sulfonated poly (ether ether ketone)/NUS-X (SPEEK/NUS-X) hybrid membranes are prepared by mixing NUS into SPEEK matrix. Among them, SPEEK/NUS-1.5 has the highest proton conductivity (177.76 mS cm −1 , 70 °C, 100% RH) and maintain a 300 h conductivity stability. And its maximum power density was 423.2 mW cm −2 , exceeding pristine SPEEK by 2.20 times. Compare to the pristine SPEEK membrane, it is interesting to note the disappearance of SAXS scattering peak of SPEEK/NUS-1.5. It is speculated that this phenomenon was caused by the generation of acid-base pairs between –NH 2 and –SO 3 H, and the improved hydrogen bonding network provides more proton transport channels and immobilizes sulfonic acid groups for improved durability. The resultant proton conductivity is stable over 300 h with about 90% retention.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xiang Ji,Yaodong Yu,Aixin Ma,Yujia Guan,Hongdong Li,Jianping Lai,Lei Wang
Nitrate (NO 3 - ) and hydrazine (N 2 H 4 ) are common nitrogen pollutants in groundwater. The electrochemical method can be used to synthesize the added product urea while treating N-pollution. Therefore, the development of sufficiently efficient electrosynthesis urea systems and efficient electrocatalysts is of great significance, but also challenging. In this paper, CuNi alloy nanosheets (Cu x Ni y /CF) on copper foam surface were synthesized by electrodeposition, and C-N coupled hydrazine oxidation (HzOR) system was constructed by proton exchange membrane (PEM). Cu and Ni in CuNi alloy act as double active sites and react with C-N coupling reaction and HzOR respectively. At −0.5 V potential, the Faraday efficiency of Cu 8 Ni 2 /CF for C-N coupling reaction is 51.66 %, and the urea yield is 254.09 μg h −1 cm −2 . At the same time, HzOR with low thermodynamic oxidation potential can quickly produce excess H + to supply protons to the cathode for C-N coupling reaction, thus significantly promoting the forward C-N coupling reaction. Cu 1 Ni 9 /CF also showed significant activity in the oxidation reaction of N 2 H 4 in KOH electrolyte. Therefore, we assembled a Cu 1 Ni 9 (+) || Cu 8 Ni 2 (-) electrolytic cell, which only needs 0.23 V working voltage up to 150 mA cm −2 , and can convert NO 3 - and CO 2 to urea at a power consumption of 5.09 kWh kg −1 while converting N 2 H 4 . Energy saving 37.6 % compared to conventional C-N coupled OER electrolytic system (about 8.16 kWh kg −1 urea). It can greatly reduce the cost of urea production, make the price of fertilizer and chemical raw materials more competitive, and promote the development of agriculture and chemical industry while reducing greenhouse gas emissions and nitrogen pollutants in the ecological environment. This study reports a promising and effective strategy for the synthesis of urea and treatment of N contaminants at a small operating voltage.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Wei Jia,Beibei Tang,Peiyi Wu
It is of great necessity to achieve a proton exchange membrane (PEM) with high proton conductivity and low methanol permeability for the practical applications. Nafion modified carbon dots (NCDs) with multi-functional groups were successfully synthesized via the pyrolysis of citric acid (CA) with the existence of Nafion. The modification process is motivated by the hydrophilicity-to-hydrophobicity transformation of CA as well as the non-covalent hydrophilic-hydrophobic interaction during the pyrolysis procedure. Multi-functionalized NCDs with moderate hydrophilicity influence the aggregation structure of Nafion matrix of the composite membranes and effectively enhance the high-temperature water retention ability. Both the proton conductivity and the methanol resistance ability of the composite PEMs are significantly enhanced. 0.5-NCD-0.5 Nafion composite PEM presents a 5–10 times increase in proton conductivity and 50% percent decrease in methanol permeability than that of recast Nafion.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
NATURE
·
2024
·Vol. 626
·期 7997
·86-91
·
IF 50.5
Fang Wensheng,Guo Wei,Lu Ruihu,Yan Ya,Liu Xiaokang,Wu Dan,Li Fu Min,Zhou Yansong,He Chaohui,Xia Chenfeng,Niu Huiting,Wang Sicong,Liu Youwen,Mao Yu,Zhang Chengyi,You Bo,Pang Yuanjie,Duan Lele,Yang Xuan,Song Fei,Zhai Tianyou,Wang Guoxiong,Guo Xingpeng,Tan Bien,Yao Tao,Wang Ziyun,Xia Bao Yu
Electrolysis that reduces carbon dioxide (CO 2 ) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future 1 , 2 , 3 , 4 , 5 , 6 . However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO 2 precipitates as carbonate, and this limits carbon utilization and the stability of the system 7 , 8 , 9 , 10 , 11 , 12 . Strategies such as physical washing, pulsed operation and the use of dipolar membranes can partially alleviate these problems but do not fully resolve them 11 , 13 , 14 , 15 . CO 2 electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution 16 , 17 , 18 . Herein we develop a proton-exchange membrane system that reduces CO 2 to formic acid at a catalyst that is derived from waste lead–acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO 2 reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO 2 at a current density of 600 mA cm −2 and cell voltage of 2.2 V and is shown to operate continuously for more than 5,200 h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.
研究领域:
化学工程
·
能源科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Xiaocui Han,Yunji Xie,Di Liu,Zheng Chen,Haibo Zhang,Jinhui Pang,Zhenhua Jiang
The advancement of proton conductive applications will require the identification of new membrane with high-conductivity and good dimensional stability that can be readily obtained and cheap. We reported a novel rigid carbazole derivative and proton exchange membrane consisting of densely sulfonated carbazole derivative, which could form aggregated ionic cluster of sulfonic acid group and result in continuous broad-dimensional nanochannels. The SAXS analysis confirmed these copolymers owned large ion clusters. All of membranes prepared in this work were thermally stable at up to 250 o C. These membranes also exhibited excellent dimensional stability and outstanding proton conductivity. SPESK-Cz-15 with IEC = 2.07 meq g -1 showed the largest water uptake with a value of 107%, but the swelling ratio was only 36.4% at 100 o C, which was attributed to the artful structure of the copolymers. SPESK-Cz-15 showed very high proton conductivity (165.3 mS cm -1 at 80 o C), which was 1.53 times higher than that of Nafion 117 (108 mS cm -1 at 80 o C). Besides, the maximum power density of SPESK-Cz-15 was 1642.7 mV cm -2 at 80 o C under 95% RH. The stability of single cell based on SPESK-Cz-15 was remarkable. All above indicate that SPESK-Cz-x are potential materials for polymer electrolyte membrane fuel cells in the future.
研究领域:
材料科学
·
化学工程
✓ 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）