APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Xianwei Li,Shuangxiu Ma,Fang Luo,Zehui Yang
Electrochemical hydrogenerations of nitrogen and oxygen molecules are of significance for nitrogen reduction and oxygen reduction reactions. Strengthening the binding between active sites and gaseous molecules is beneficial for enhancing the catalytic performance, especially in NRR catalysis. In this work, we have engineered the oxygen vacancies in Co 3 O 4 nanoparticles to boost the catalytic activity towards NRR and ORR. Ascribing to the p-d hybridization between Co and N atoms, N 2 electrochemical adsorption is promoted and the related energy barrier of N 2 protonation is significantly decreased by 50%; as a consequence, Faradaic efficiency is 11.2% at −0.4 V vs. RHE, 3-fold higher than Co 3 O 4 /CNT; moreover, due to the oxygen vacancies in Co 3 O 4-x /CNT leading to a higher oxophilicity, Co 3 O 4-x /CNT showed a better selectivity in ORR catalysis and kinetic current density at 0.85 V vs. RHE is boosted by 2.4 times. Consequently, Co 3 O 4-x /CNT exhibits a better rechargeable zinc air battery performance than Pt/C-IrO 2 by a factor of 2.2.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Zhaomin Chen,Zhenyu Wu,Jia Xu,Rui Zhao,Xiaoxia Han,Jiwei Jiang,Mingwang Shao,Bin Dong,Zhenhui Kang
Photochemical devices show great potential in applications ranging from electrical energy storage to future smart grids. Here, we report a metal-free composite film cell based on carbon dots (CDots) and polyaniline (PANI), which could achieve 24/7 discharge and photo-charging in seawater. CDots/PANI film cell has an open-circuit-voltage (OCV) of 0.95 V, a maximum power density of 380 mW m 2 , and the ability to discharge continuously for 40 h under solar irradiation of AM 1.5 G. It couples the reduction reaction of PANI, and the CDot-catalyzed oxygen reduction reactions (ORR) during discharge. While the light-induced CDot-catalyzed oxygen evolution reaction (OER) and the reduction reaction of PANI during charging. In particular, in-situ TPV tests were used to verify the effect of the light-induced OER and the kinetic properties of the catalyst on the charge transfer at the interface. We believe this research may provide new ideas for sustainable energy conversion and storage.
研究领域:
材料科学
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能源转换与存储
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Hao Jiang,Yian Wang,Jue Hu,Xuxia Shai,Chengxu Zhang,Thiquynhxuan Le,Libo Zhang,Minhua Shao
Hydrogen peroxide (H 2 O 2 ), as one of the most important chemicals, is widely applied in many industries. Electrocatalytic oxygen reduction provides a safe and on-site method for H 2 O 2 synthesis. The research of transition metal oxides (TMOs) for H 2 O 2 synthesis is mainly focused on the modification of transition metal elements and graphene. Few studies directly control pure TMOs without changing supporting materials or introducing other elements. Here, we demonstrate for the first time a phase regulation strategy to develop highly selective and stable tungsten trioxide catalysts for H 2 O 2 generation through 2e − oxygen reduction reaction (2e − ORR). DFT calculations show that the kinetic energy barrier (0.08 eV) of the 2e − ORR pathway on the cubic tungsten trioxide (c-WO 3 ) surface is much lower than that of the 4e − ORR pathway (0.76 eV). As a result, a selectivity of 90 % and H 2 O 2 production rate of 179 mmol g cat −1 h −1 are achieved at 0.1 V vs RHE under alkaline conditions, outperforming all catalysts previously reported under the same conditions. Moreover, after continuous testing for more than 24 h at a constant potential of 0.1 V vs RHE, the H 2 O 2 generation rate has not been diminished, indicating an excellent stability of c-WO 3 in practical applications.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 14
·4389-4397
·
IF 4
Yujun Wu,Wei Shuang,Lin Yang,Chuanbao Cao
Graphene-based materials have been regarded recently as a promising substance for electrochemical energy conversion and storage devices owing to their unique structure and extraordinary properties. Herein, an enormously facile one-step pyrolysis approach is reported for the fabrication of ternary (P,S,N)-doped graphene, which is further investigated as an efficient metal-free electrocatalyst for the oxygen reduction reaction (ORR). Furthermore, optimized ternary-doped graphene can deliver excellent ORR catalytic activity that favors the four-electron ORR process and outstanding long-term durability (90.54% current retention after 20000 s which is far superior to that of commercial Pt/C) owing to the preferable synergetic coupling effect between P, S and N. Density functional theory (DFT) calculations were performed to reveal the synergetic coupling effect between doping elements in the ORR process. This work provides an extremely simple one-step pyrolysis method for the synthesis of P,S,N-doped graphene for electrochemical energy conversion and storage devices.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Chang Li,Wenlong Wang,Sheng Zhu,Hui Pan,Qunjie Xu,PengHui Shi,YuLin Min
One of the important factors affecting the actual service life of proton exchange membrane fuel cells (PEMFCs) is that catalysts agglomeration and carbon carrier corrosion will be accelerated by operating temperatures. In this paper, through a simple F-doping strategy, F-doped carbon-supported PtZn i-NPs (PtZn i-NPs/F-C) catalysts were prepared. The metal-support interaction (MSI) was enhanced by doping the element F. This also inhibited catalyst aggregation and increased Pt element oxygen reduction reaction (ORR) activity. Aside from this, the electronegativity of F prevents reactive oxygen species (ROS) from attacking the carbon support during the reaction process, ensuring that after 5000 CV cycles at 80 °C, the catalysts still maintain ∼0.856 V as a half-wave potential, only losing 9 mV, much higher than the half-wave potential of commercial Pt/C after 5000 CV cycles (∼0.777 mV). This work provides a brand-new perspective on solving the problems caused by the increase in the operating temperature of PEMFCs, and also provides a new idea for the preparation of electrocatalyst for ORR.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2023
·
IF 2.8
Li Wei,Zhao Yi,Zhang Chunyan,Kang Juanxue,Tang Qinyuan,Liu Yongfei,Yang Lin,Yuan Shutang
The production of hydrogen peroxide (H 2 O 2 ) by 2-electron oxygen reduction reaction (ORR) in acidic electrolytes is a promising alternative to the existing anthraquinone process. However, the development of cost-effective catalysts with high activity for H 2 O 2 electrosynthesis remains a great challenge. Here, we report a cobalt-nitrogen-carbon catalyst in which cobalt single atoms are supported on carbon black (Co-N-CB) for the electrosynthesis of H 2 O 2 in an acid medium. The prepared Co-N-CB shows high activity for O 2 reduction into H 2 O 2 with an average selectivity of 80.6% over a wide potential range of 0.1–0.7 V vs. RHE in 0.1 M HClO 4 electrolytes. We found that (i) the Co single atoms are the active sites of 2-electron ORR; (ii) a catalyst for efficient H 2 O 2 production by O 2 reduction should achieve a good balance between high ORR activity and H 2 O 2 selectivity. Using Co-N-CB as a cathodic catalyst, the electrochemical device could electrosynthesize H 2 O 2 directly from H 2 and O 2 with a high productivity of 291.0 mol kg cat −1 h −1 . Our work provides a flexible way to prepare affordable catalysts for efficient H 2 O 2 electrosynthesis.
研究领域:
材料科学
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催化化学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2025
·
IF 4.1
Shao-Hui Huang,Jie Wu,Jing Chi,Tai-Shen Yang,Jin-Chao Cao
Selective dissolution is an effective strategy to improve the catalytic performance. This method was used to regulate the surface structure of SmMn 2 O 5 through HNO 3 acidification to promote its oxygen reduction reaction (ORR) performance. The relationship between the structures and ORR performances of SmMn 2 O 5 acidified by different concentrations of HNO 3 (5-8 M) was investigated. HNO 3 can selectively dissolve part of Sm, which reduces Sm/Mn ratio, and increases Mn 4+ /Mn 3+ and surface adsorbed oxygen/lattice oxygen ratios on the catalyst surface. Especially, the increase of Mn 4+ content optimizes the adsorption of oxygen-containing intermediates on Mn 3+ active sites and enhances the ORR activity. When treated with 7 M HNO 3 for 10 h, the acidified SmMn 2 O 5 surface has suitable Mn 4+ /Mn 3+ ratio, exhibiting excellent ORR performance. Compared with SmMn 2 O 5 , the half-wave potential of the acidified SmMn 2 O 5 increases from 0.80 V to 0.83 V, and the diffusion-limited current density improves from 3.44 mA·cm −2 to 4.76 mA·cm −2 . Additionally, the synergistic catalytic mechanism of Mn 4+ with Mn 3+ active sites was well discussed.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
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IF 8.1
Ziyi Wang,Yuqin Wei,Zhaoli Xue,Lei Feng,Aijian Wang,Yan Sun,Chunsheng Li,Xinping Qiu,Long Zhao
Asymmetric metalloporphyrins are potential electrocatalysts to construct composites for efficient oxygen reduction reactions (ORRs) due to their inherent large dipole moment , which facilitates the charge separation. To find more effective molecular structures towards the ORRs, in particular their performance and electrolyte relationship, we rationally designed two A3B-type asymmetric cobalt porphyrin aPh-TCoP and aBA-TCoP with phenyl and benzoic acid as substituents, respectively. The ORR performance of the porphyrin-decorated carbon black composites was examined in five electrolytes at different pH values spanning from 0.7 to 13.7. It was found that aBA-TCoP/C exhibited better ORR activity and selectivity than aPh-TCoP/C in all solutions. Interestingly, both composites demonstrated their highest ORR activity in the pH13.7 electrolyte and exhibited 4-electron selectivity in the pH3.7 solution. This conclusion is drawn from a comprehensive analysis of various electrochemical properties , encompassing current density , reduction potentials, electron transfer numbers, and intermediate yields. The results illustrate the regulation of ORR properties by altering the electrolyte pH and a notable improvement in the ORR performance through the modification of porphyrin substituents. These findings offer a foundational understanding for the design of efficient metalloporphyrins and the attainment of controlled oxygen reduction in electrochemical devices .
研究领域:
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Zheqin Chen,Yongmin Xie,Xiaocong Zhong,Zhifeng Xu
Although metal–air batteries emerge as a highly promising class of fuel cells, improved efficiency is required for the oxygen reduction reaction (ORR) at the air–electrode cathode. Perovskite-type oxides, such as Co-doped LaNiO 3 , can serve as low-cost alternatives to conventional precious-metal-based oxygen electrocatalysts. However, achieving high specific surface areas and oxygen reduction activities necessitates the optimization of the synthesis process. In this study, LaNi 0.5 Co 0.5 O 3 (MV-LNCO), a high-performance perovskite ORR catalyst, is synthesized via an innovative sol–gel method combined with microwave heating. This approach involves the use of polyvinylpyrrolidone as a complexing agent and activated carbon as a pore-forming agent. Notably, the specific surface area of MV-LNCO (50.78 m 2 g −1 ) is nearly twice as large as that of the corresponding catalyst synthesized using the traditional method. Moreover, electrochemical tests revealed that MV-LNCO achieves an improved onset potential (0.87 V), half-wave potential (0.68 V), and limiting current density (5.57 mA cm −2 ) for ORR. In addition to its excellent catalytic activity in ORR, MV-LNCO demonstrates no notable decrease in current output over 8 h, indicating excellent stability. Thus, the developed synthesis method has the potential to provide novel high-performance catalysts for metal–air batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2024
·Vol. 10
·期 42
·
IF 11.7
Yanling Ma,Jiaheng Peng,Jiakang Tian,Wenpei Gao,Jialiang Xu,Fan Li,Peter Tieu,Hao Hu,Yi Wu,Wenlong Chen,Lei Pan,Wen Shang,Peng Tao,Chengyi Song,Hong Zhu,Xiaoqing Pan,Tao Deng,Jianbo Wu
Shape-controlled alloy nanoparticle catalysts have been shown to exhibit improved performance in the oxygen reduction reaction (ORR) in liquid half-cells. However, translating the success to catalyst layers in fuel cells faces challenges due to the more demanding operation conditions in membrane electrode assembly (MEA). Balancing durability and activity is crucial. Here, we developed a strategy that limits the atomic diffusion within surface layers, fostering the phase transition and shape retention during thermal treatment. This enables selective transformation of platinum-iron nanowire surfaces into intermetallic structures via atomic ordering at a low temperature. The catalysts exhibit enhanced MEA stability with 50% less Fe loss while maintaining high catalytic activity comparable to that in half-cells. Density functional calculations suggest that the ordered intermetallic surface stabilizes morphology against rapid corrosion and improves the ORR activity. The surface engineering through atomic ordering presents potential for practical application in fuel cells with shape-controlled Pt-based alloy catalysts.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Xuedong He,Yujian Zhang,Juan Wang,Jun Li,Lianghao Yu,Feng Zhou,Juan Li,Xiaojun Shen,Xin Wang,Shun Wang,Huile Jin
Metal compounds encapsulated in carbon materials exhibit promising properties as potential oxygen electrocatalysts. Herein, we first report Fe2N@C derived from the biomass bioaccumulation doping method, which offers a new perspective for exploring oxygen reduction reaction (ORR) electrocatalysts with low cost and high performance. The Fe2N@NCNTs prepared with our biodoping method display excellent ORR activity with a low half-wave potential (E1/2) and long-term stability in a broad pH range. More importantly, a zinc–air battery (ZAB) constructed with Fe2N@NCNTs’ catalysts exhibits a high open-circuit voltage (1.53 V), high peak power density (135 mW cm–2), and excellent stability (over 200 h). The significantly improved ORR performance can be attributed to the high N-doping level and its hierarchically porous structure. This work offers a path for the development of ORR catalysts for environmental governance and efficient energy conversion.
研究领域:
材料科学
·
能源科学
·
环境科学
✓ 已验证
DOI
高影响因子
Cell Reports Physical Science
·
2022
·
IF 7.832
Menghui Chen,Junxiang Chen,Chunguang Jia,Jin Luo,Zhili Yang,Joey Chung-Yen Jung,Jiujun Zhang,Shengli Chen,Shiming Zhang
New carbon morphologies are desirable in the development of high-performance carbon-based electrocatalysts for cathodic oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells. In this work, a carbon semi-tube (CST) is successfully constructed by polymerizing m -phenylenediamine (mPDA) using surfactant-assembled micelles as a soft template. After pyrolysis, the CST morphology is retained in the formed N-doped CST (N-CST) catalyst. This mPDA-induced catalyst can provide rich micropores, high N-content, and good conductivity, imbuing it with superior catalytic ORR activity, stability, and methanol tolerance to the commercial Pt/C catalyst. By using such a metal-free N-CST as a cathode catalyst, an alkaline polymer electrolyte fuel cell exhibits a maximum power density of about 200 mW cm −2 . Furthermore, density functional theory (DFT) calculations suggest that high curvature can be greatly conducive to the excellent catalytic ORR activity by the induced strong OOH∗ adsorption on active sites through a strong dipole-electric field interaction.
研究领域:
材料科学
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）