NEW CARBON MATERIALS
·
2021
·
IF 1.905
Jing Zhang,Lianghao Song,Chenfei Zhao,Xiuping Yin,Yufeng Zhao
Although the Co and N co-doped carbon catalyst (Co-NC) has attracted much attention because of its low cost and the natural abundance of the dopants, it has a low oxygen reduction reaction (ORR) activity and a high selectivity for the two-electron (2e - ) reduction of oxygen to H 2 O 2 , which affects its use in fuel cells. Co-NC catalysts were prepared by the pyrolysis of a mixture of cobalt chloride and chitosan pretreated with zinc chloride at 650, 750 and 850 o C, followed by washing with nitric acid and annealing at 900 o C. The results indicate that zinc chloride helps the complexing of chitosan with Co 2+ , which is also a chemical activator that generates pores, and annealing caused the evaporation of the spherical Zn metal nanoparticles formed by the carbothermal reduction of Zn ions, leading to a unique porous structure of the catalysts with spherical pores filled with spherical carbon nanoparticles formed by the growth of nitrogen-doped carbon as a result of the Co catalyst. The degree of graphitization is also improved by the Co catalyst. The Co-NC catalyst obtained at a pyrolysis temperature of 750 o Cshows the same four-electron (4e - ) reduction of oxygen as a commercial Pt/C catalyst, and a significantly higher ORR catalytic activity, longer-term stability and better methanol tolerance than a commercial Pt/C catalyst. These are due to its large specific surface area, high contents of pyridinic nitrogen and graphitic nitrogen that disperse the Co species and its excellent electrical conductivity.
研究领域:
材料科学
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电化学
·
催化
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shuxiu Yang,Qingzhu Shu,Bona Fu,Shuhong Liu,Yong Zhang,Hong Zhao
One important approach to address the cost issue of fuel cells is to maximize the utilization of Pt by reducing its loading and enhancing the performance for the oxygen reduction reaction (ORR) as well as durability of catalysts. In this work, a one-step synthesis of highly dispersed low-Pt (1 1 1) electrocatalysts (p-Pt/KBs) supported by Ketjenblack is conducted using interaction between solution and nonthermal plasma (SNP). The results show that the plasma-treated platinum precursor dispersion efficiently avoids particle agglomeration and increases more defects of the support surface, which are conducive to the trapping and anchoring of platinum nanoparticles (Pt NPs). The catalyst (p-Pt/KB-NaOH) with a platinum load of 10.8 wt% is obtained by adding sodium hydroxide to the platinum precursor dispersion solution, showing better ORR performance (E 1/2 = 0.88 V) and stability compared to the commercial platinum on carbon (Pt/C) catalyst (20 wt%, E 1/2 = 0.86 V). This improvement is attributed to the fact that neutralizing chloroplatinic acid slows down the reduction rate of the platinum precursor, effectively controlling the rapid nucleation and slow crystal growth of platinum. As the cathode catalyst for PEMFCs, p-Pt/KB-NaOH exhibits remarkable mass-transfer performance in the high-current density domain (HCD), with maximum power density (P max ) of 1131 mW cm −2 at 2500 mA cm −2 , which is 9.1 % higher than commercial Pt/C. Moreover, the single-cell operates stably for at least 100 h at 1000 mA cm −2 with a negligible decay (1.9 %) of the working voltage, ensuring long-term durability.
研究领域:
材料科学
·
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
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Qingtao Wang,Xia Hu,Kai Cui,Yanxia Wu,Guofu Ma,Ziqiang Lei,Shufang Ren
An oxygen reduction reaction (ORR) catalyst is a crucial component of metal–air batteries. Herein, modified carbon nanotubes are used to support iron phthalocyanine, followed by the fabrication of single-atom and cluster coexisting catalysts by the fast microwave method. The two catalysts have Fe–N5 and Fe–P–N4 coordination structures, respectively. Electrochemical tests show that the FeNC/Fe–N5–C and FeNC/Fe–P–N4–C catalysts have half-wave potentials of 0.906 and 0.886 V in an alkaline solvent, respectively. The Zn–air battery prepared with the FeNC/Fe–N5–C catalyst has a specific capacity of 791 mA h g−1 and a maximum power density of 190 mW cm−2. DFT calculations show that the axial coordination bonds in FeNC/Fe–N5–C and FeNC/Fe–P–N4–C are conducive to the acceleration of the transfer of electrons. The d-band centers of the axial coordination Fe–N5 and Fe–P–N4 are closer to the Fermi level, confirming that the presence of the axial coordination bonds enhances the adsorption of the reaction intermediates and reduces the ORR barriers.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2024
·
IF 4.1
Bolong Liang,Ming Su,Zhe Zhao,Shu-xuan Liang
Microbial fuel cell (MFC), simultaneously degrading organic pollutants and harvesting electricity, suffers from a sluggish oxygen reduction reaction (ORR) on cathode. The catalysts for Pt substitution are crucial to enhance the ORR performance and power output. Thus, a Co and Fe co-doped carbon derived from ZIF-67 (Co/Fe-NC) is prepared, which is proved to have excellent electrochemical properties. When the catalyst Co/Fe-NC is equipped in microbial fuel cell, the maximum power density of 1831 ± 57 mW m −2 is achieved, which is 13.5 % higher than that of Fe@Co-NC and 49.3 % higher than that of Co-NC. Moreover, the electrochemical tests show that Co/Fe-NC has a smaller charge transfer resistance and a higher exchange current density, which implies the faster kinetics of ORR. The enhanced performance of Co/Fe-NC can be attributed to the rougher rhombic dodecahedral interface, larger surface area, various types of nitrogen species, critical roles of cobalt and iron species, both high graphitization and defects. All these characteristics are responsible for the significant increase in ORR activity and power output. This work designs and compares different catalysts derived from iron-involved ZIF-67, and demonstrates a superior ORR electrocatalyst of Co/Fe-NC, which can be a potential alternative to Pt in the MFC practical application.
研究领域:
环境科学
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材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2026
·
IF 13.6
Yuyan Wan,Dai Dang,Ning Yan
Oxygen reduction reaction (ORR) catalysts based on M-N-C materials often exhibit promising activity in aqueous electrochemical tests but suffer from rapid degradation under practical fuel cell operation. This discrepancy can originate from different reaction environments, where conventional measurements fail to reproduce the high flux of reactive oxygen species (ROS) present at the triple-phase boundary in membrane electrode assemblies (MEAs). Here, we establish an operando protocol that quantitatively bridges this gap by determining the concentration of H2O2 and derived ROS under realistic fuel cell conditions and then reproducing such oxidative environments in aqueous media via H2O2 injection. Using CoCe-NC as model catalysts, in which Co sites act as stable ROS generators and Ce sites serve as radical scavengers, we demonstrate that atomic-scale proximity between ROS generation and scavenging sites critically governs radical mitigation efficiency and catalyst stability. By tuning inter-site distances, we show that enhanced durability arises from accelerated and localized ROS removal rather than intrinsic stabilization of the carbon matrix. This work establishes a generalizable framework for quantifying and reproducing realistic oxidative environments, enabling mechanistic investigation of ROS-driven degradation that is inaccessible by conventional methods, and providing guidance for the rational design of durable PGM-free ORR catalysts.
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yue Du,Zhiyi Zhong,Zhixian Shi,Lina Zhou,Song Pan,Xiaonan Xu,Yisi Liu,Dongbin Xiong,Kai Wang
The development of carbon-encapsulated alloy catalysts, through a rational design that integrates highly active Me-N-C sites, is essential for improving the reaction kinetics of both oxygen reduction (ORR) and oxygen evolution reactions (OER). This advancement is pivotal for the progression of efficient rechargeable zinc-air batteries (RZABs). In this study, we investigates a CoNi alloy decorated N-doped carbon nanotube (CoNi-NCNT) electrocatalyst using a dual-ligand strategy. Experimental characterizations and theoretical calculations reveales that the electronic modulation of the 3 d orbitals of the CoNi alloy by the CoN 3 sites enhances electronic conductivity during the ORR/OER process, leading to exceptional bifunctional activity. Electrochemical evaluations demonstrates the outstanding performances of CoNi-NCNT, with a half-wave potential of 0.81 V (versus RHE) for ORR and a low overpotential of 1.52 mV for OER at 10 mA cm −2 . Moreover, the CoNi-NCNT catalyzed Zn-air battery exhibits a remarkable specific capacity of 780 mAh g −1 and an exceptionally extended lifespan exceeding 800 h. This underscores the potential of this alloy strategy in the development of high-performance bifunctional ORR/OER electrocatalysts.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Hongwei Zhao,Lixiang Li,Yuanyuan Liu,Xin Geng,Haiming Yang,Chengguo Sun,Baigang An
A simple one-step CVD of acetonitrile vapor was successfully used to prepare nitrogen-doped ordered microporous carbon, where zeolite template was silanized to improve activity of carbon deposition into pore walls of the zeolite, CVD time was used to adjust microstructure and nitrogen containing species. XRD, N 2 adsorption isotherms, SEM, TEM and XPS were used to characterize the composition, microstructure, specific surface area (SSA)/pore distribution and chemical state of nitrogen-doped zeolite-templated carbons (N-ZTCs). Electrochemical tests were carried out to analyze the performance of samples as ORR catalyst. The results show that the N-ZTC as prepared at 750 °C with CVD time of 4 h (N-ZTC-4h) owns ordered micropores, large SSA and abundant nitrogen containing functional groups. As metal free catalyst, N-ZTC-4h exhibits high current density of ORR, good durability and excellent methanol tolerance. Good catalytic ORR performance of N-ZTC-4h is owed to a large quantity of nitrogen containing species with a high ratio of pyridinic-N and quaternary-N owning activity of ORR and the ordered microporous distribution in three-dimensions for mass transport. Easy preparation process and control method of pore structure and nitrogen containing species of N-ZTCs makes it have a big potential in developing nitrogen doped carbon based catalysts of ORR.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Xiaolan Li,Yangqi Huang,Zhenyu Chen,Shuqi Hu,Jinliang Zhu,Panagiotis Tsiakaras,Pei Kang Shen
A series of tri-functional nanoflower (NF) catalysts with numerous nanodendrites (Pt 3 NiRh, Pt 3 NiRu, Pt 3 NiPd, Pt 3 Ni, and Pt 2 Ni 2 Rh NFs) were synthesized by introducing Rh, Ru, and Pd into Pt-Ni nanoflowers, aiming at accelerating the sluggish kinetics of oxygen reduction reaction (ORR), methanol oxidation reaction (MOR), and hydrogen evolution reaction (HER). The as-prepared catalysts displayed superior anti-poisoning ability and excellent activity due to uniform morphology and good dispersibility. Their electrochemical characterization revealed that the Pt 3 NiRh NFs showed the highest mass activity (2.17 A m g P G M - 1 ) and specific activity (3.13 mA cm -2 ) toward ORR, close to 9.9 and 4.6 times higher than the values measured on Pt/C (46.7 %). As for MOR, mass and specific activities of Pt 3 NiRh NFs were 1.88 A m g P G M - 1 and 2.62 mA cm -2 , far exceeding the values on commercial Pt/C. Moreover, HER activity of Pt 3 NiRh NFs outperformed commercial Pt/C. This work is valuable to develop promising multi-functional catalysts with enhanced activity and anti-poisoning ability.
研究领域:
材料科学
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电化学
·
催化领域
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Jiewen Liu,Jian Zhang,Mingjie Xu,Chuanjin Tian,Yanhao Dong,Chang-An Wang
The primary challenge for efficient H2 evolution and hydrogen energy conversion is to develop highly active and stable catalysts with simple and reliable preparation processes. In this regard, we have designed and synthesized a porous carbon-supported low-Pt alloy catalyst (Pt3Co/Co@C composite) using ZIF-67 as a template. It showed uniformly dispersed Pt3Co/Co on the porous carbon layer due to the confinement effect of the porous carbon layer. Pt3Co/Co@C demonstrated excellent activity for the hydrogen evolution reaction in the full pH range, with an overpotential of 187 mV in 0.5 M H2SO4 to attain 100 mA/cm2 as well as long-term stability. It also displayed superior mass activity for the oxygen reduction reaction (ORR) at 0.85 V (vs RHE) compared to the commercial Pt/C. Furthermore, the Pt3Co/Co@C catalyst exclusively enabled a four-electron reaction process under ORR conditions without the competitive pathway to H2O2. The current work provides guidance for the design and facile synthesis of Pt-based catalysts with enhanced performance.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Aling Chen,Qingfeng Yi,Kuang Sheng,Yuebing Wang,Jiangchuan Chen,Qiaoli Zhang,Kaiwen Xiang,Guanghua Tan
Development of high-efficiency oxygen reduction reaction (ORR) catalysts under neutral conditions has made little research progress. In this work, we synthesized a three-dimensional porous N/P codoped carbon nanosheet composites (CNP@PNS) by high-temperature thermal treatment of dicyandiamide, starch, and triphenylphosphine and subsequent porous structure-making treatment using the NaCl molten salt template. In the neutral solution, the electrocatalytic performance of the CNP@PNS-4 catalyst exhibits an onset potential of 0.98 V (vs reversible hydrogen electrode) and a half-wave potential of 0.91 V for ORR, which greatly surpasses commercial Pt/C (40%). Three kinds of neutral metal–air batteries (Zn–air, Al–air, and Fe–air) using the prepared samples as cathodic catalysts were constructed, corresponding to the maximum power density of 120.2, 78.3, and 18.9 mW·cm–2, respectively. Also, they reveal outstanding discharge stability under different current densities. The density functional theory calculation depicts the reduction of the free energy of the determining step and subsequent decline of the overpotential for ORR.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 8
·3381-3393
·
IF 3.5
Zhang Feng,Wang Hao
Exorbitant cost and limited availability of platinum-based electrocatalysts for the oxygen reduction reaction (ORR) in metal–air batteries and alkaline fuel cells pose significant obstacles to the large-scale commercialization of these clean-energy technologies. Herein, we employed a cost-effective and sustainable bacterial cellulose biomass as the precursor to prepare a nitrogen and fluorine codoped metal-free ORR electrocatalyst (BCC-NF-900) by direct pyrolysis regulation. The BCC-NF-900 inherited the three-dimensional framework of bacterial cellulose, exhibiting a robust porous structure with a Brunauer–Emmett–Teller surface area of 196.9 m 2 ·g −1 . The pyridinic N (0.6 at%) and semi-ionic F (0.34 at%) species formed in the inert sp2 carbon skeletons synergistically regulated the electron spin and charge density of the adjacent C atoms. Such rational combination of a rapid transport pathway and effective active site led to high ORR activity (onset potential 0.89 V vs. RHE), methanol resistance, and electrochemical stability (merely 6.9% current loss) in alkaline electrolyte. Importantly, compared to the mere F-doped BCC-F-900 (onset potential 0.82 V vs. RHE) and N-doped BCC-N-900 (onset potential 0.77 V vs. RHE) catalysts, the BCC-NF-900 catalyst exhibited a markedly enhanced ORR performance, as evidenced by the measured onset potential. This study provides an available reference for the design of efficient metal-free catalysts for ORR, presenting a promising alternative to Pt/C catalysts in metal–air batteries and alkaline fuel cells.
研究领域:
材料科学
·
电化学
·
能源技术
·
纳米技术
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环境科学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2018
·
IF 4.155
Song Xing,Luo Shuiping,Fan Xiaokun,Tang Min,Zhao Xixia,Chen Wen,Yang Qi,Quan Zewei
Well-defined PtNi nanocrystals represent one of the most efficient electrocatalysts to boost the oxygen reduction reaction (ORR), especially in the shape of octahedrons, nanoframes, and nanowires. However, the synthesis of complex PtNi nanostructure is still a great challenge. Herein, we report a new class of PtNi hexapods with high activity and stability toward ORR. The hexapods are prepared by selective capping and simultaneous corrosion. By controlling the oxidative etching, PtNi polyhedrons and nanoparticles are obtained, respectively. The intriguing hexapods are composed of six nanopods with an average length of 12.5 nm. Due to their sharp tips and three-dimensional (3D) accessible surfaces, the PtNi hexapods show a high mass activity of 0.85 A mgPt-1 at 0.9 V vs. RHE, which are 5.4-fold higher than commercial Pt/C, also outperforming PtNi polyhedrons and PtNi nanoparticles. In addition, the mass activity of PtNi hexapods maintains 92.3% even after 10,000 potential cycles.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）