RSC Advances
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2023
·Vol. 13
·期 6
·3835-3842
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IF 3.9
Tanlun Wang,Lincheng Xu,Chenxiang Sun,Xiyuan Li,Yong Yan,Fan Li
Fe–N–C has a high number of FeNx active sites and has thus been regarded as a high-performance oxygen reduction reaction (ORR) catalyst, and combining Fe3C with Fe–N–C typically boosts ORR activity. However, the catalytic mechanism remains unknown, limiting further research and development. In this study, a precipitation-solvothermal process was used in conjunction with pyrolysis to produce a series of Fe–N–C catalysts derived from a zeolitic imidazolate framework (ZIF) that was composited with Fe3C. The prepared catalysts had a multiscale structure of ZIF-like carbon particles and rod-like structures, as well as bamboo-like carbon nanotubes (CNTs) and carbon layers wrapped with Fe3C particles while a series of studies revealed the origin of the rod-like structures and Fe3C phase. The hierarchical structure was beneficial to the enhanced electrocatalytic performance of catalysts for ORR. The optimal sample had the highest half-wave potential of 0.878 V vs. RHE, which was higher than that of commercial Pt/C (0.861 V vs. RHE). The ECSA of the optimal sample was 1.08 cm2 μg−1, with an electron transfer number close to 4, and functioning kinetics. The optimal sample exhibited high durability and methanol tolerance for the ORR. Finally, blocking different Fe active sites with coordination ions demonstrated that Fe(II) was the main active site, indicating that Fe3C primarily served as a cocatalyst to optimize the electron structure of Fe–N–C, thereby synergistically improving the ORR activity.
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Xiaodong Chen,Ning Wang,Kui Shen,Yangkai Xie,Yongpeng Tan,Yingwei Li
In order to improve the catalytic performance of oxygen reduction reaction (ORR), it is pivotal to increase the density and accessibility of the active sites. Herein, we have developed a template-free melamine-assisted cocalcined strategy to afford Fe-embedded and N-doped carbons (Fe–N–C) with not only high density of atomically dispersed Fe–Nx active sites but also abundant three-dimensional interconnected mesopores by directly pyrolyzing Fe-ZIF-8 covered with a controllable melamine layer. It is demonstrated that the introduction of melamine in the precursor plays a key role in constructing various carbonized products with controllable morphology, porosity, and components. With an optimal mass ratio 1:1 of melamine to Fe-ZIF-8, the resultant Fe@MNC-1 exhibits excellent ORR activity and stability, which exceeds 20 wt % commercial Pt/C catalyst (with a half-wave potential of 0.88 V vs 0.85 V) in an alkaline electrolyte and is even comparable to the commercial Pt/C catalyst (with a half-wave potential of 0.78 V vs 0.80 V) in an acidic electrolyte. To the best of our knowledge, Fe@MNC-1 can be ranked among the best nonprecious metal electrocatalysts for ORR in both alkaline and acidic media. The present synthetic strategy may provide a new opportunity for the design and construction of metal–organic framework-derived nanomaterials with rational composition and a desired porous structure to boost their electrocatalytic performance.
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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纳米材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Haiqian Zhao,Shuaishuai Han,Jiuyang Jia,Mingqi He,Kaibo An,Ziyu Tang,Shiwei Lai,Xue Yang,Zhonghua Wang
The adsorption of carbon materials and 2e-ORR performance can be promoted by N-doping. However, the effect of different N-doping types on adsorption and 2e-ORR and their synergy is not clear, which limits the development of an electro-Fenton system. To enhance the degradation efficiency of the electro-Fenton system, it is essential to understand the mechanisms involved in regulating cathode performance. To achieve this goal, a multi-scale simulation approach was employed that integrates molecular dynamics and quantum chemical simulations. This method was utilized to fabricate carbon planes with various N-doping types. The simulation results showed pyridinic-N and pyrrolic-N showed a cooperative effect and promoted the capacity of activated carbon to adsorb tetracycline. Graphitic-N and pyridinic-N greatly improved the selectivity of 2e-ORR, which is conducive to the formation of H 2 O 2 . Experimental investigations have revealed a synergistic association between adsorption and 2e-ORR, and suboptimal performance of either process can hinder the degradation efficacy of electro-Fenton. The reason for this is that an exceptional selectivity of 2e-ORR enhances the production of ·OH, and good adsorption capability facilitates the utilization of ·OH. The MAC cathode exhibits a greater synergistic effect between adsorption and 2e-ORR owing to the suitable proportion of pyridinic-N, pyrrolic-N, and graphitic-N. Under the action of high-efficiency synergy, the degradation effect of tetracycline by the electro-Fenton cathode was 8.72%-11.64% higher than that of other modified cathodes. The outcomes of our investigation provided insights into the approach for targeted control of the performance of N-doped modified cathodes in the electro-Fenton system.
研究领域:
环境科学
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材料科学
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化学工程
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电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Jiarun Cheng,Chaojie Lyu,Hangren Li,Jiwen Wu,Yue Hu,Bin Han,Kaili Wu,Mirabbos Hojamberdiev,Dongsheng Geng
An original strategy was reported to manipulate ORR selectivity of N-doped hollow mesoporous carbon spheres (N-HMCS) via heteroatom (P and S) doping. Heteroatom doping can not only modulate electronic structure of N-HMCS and proportion/configuration of doped N, but also regulate ORR pathway. Specifically, rich-graphitic N sites and electron-rich C–P bond domains in N,P-HMCS act as electron donors, making *OOH more unstable and easier to desorb into H 2 O 2 . This severely distorts the sp 2 lattice of graphene, catalyzing a two-electron ORR synergistically. Conversely, a strong interaction between electron-deficient C–S bond domain and *OOH intermediate due to the introduction of highly electronegative S hinders the desorption of *OOH, leading to the breakage of the O–O bond and promoting four-electron ORR along with the rich-pyridinic N receptor site. The reaction activity and kinetics mechanism present a positive correlation with proportion of graphitic N, revealing graphitic N is the primary active site with a much faster electron transfer capacity.
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
·
IF 15.1
Chen Li,Yaowen Zhang,Min Yuan,Yang Liu,Haikuo Lan,Zhenjiang Li,Kang Liu,Lei Wang
Regulating the atomic coordination ambiance of uniformly distributed single atoms (SAs) via heteroatom doping is an up-and-coming method to facilitate the catalytic activity for oxygen reduction reactions (ORR). With the cooperative interaction of dual heteroatom doping supplied extra degrees of freedom, a greater efficiency of ORR can be realized via a reduction in intermediate energy barrier during catalytic reactions. Here, we explore a fresh approach to generate N, S co-doped Fe-SA in embedded porous carbon nanosheets/carbon nanotubes (Fe-N X @NSCST-ZL) utilizing a 2D leaf-shaped MOF as a template in this work. Taking advantage of the combined effect of carbon matrix and nanotubes as well as the abundance of Fe-N X active sites and thiophene-S, the Fe-N X @NSCST-ZL provides exceptional performance for ORRs with a half-wave potential of 0.94 V at alkaline conditions, 0.77 V at acidic conditions, and 0.74 V at neutral conditions (V vs. RHE). Furthermore, Fe-N X @NSCST-ZL-based Zn-air battery, as well as quasi solid-state flexible battery, maintain steady operation for 765 h and 30 h with a small discharge/charge interval, respectively. This work contributes perspectives on the reasonable design of economical single-atom catalysts (SACs) for applications in energy conversion that have outstanding electrocatalytic potential.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
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2024
·Vol. 56
·期 10
·596-612
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IF 1.5
Xue-qi Zhang,Qing-xian Yue,Rui Ding,Jie Liu
Corrosion protection of steel bars in alkaline concrete environments poses a common challenge in marine engineering. One approach to mitigate steel bar corrosion is the addition of corrosion inhibitors to the concrete. In alkaline environments, the passivation of rebars occurs through anodic passivation coupled with the cathodic oxygen reduction reaction (ORR). The catalysis of ORR can expedite anode passivation. To investigate the corrosion inhibition of steel bars in alkaline environments, meso-tetra(4-carboxyphenyl)porphine (TCPP), known for its ORR catalytic properties, is selected. TCPP forms adsorption films on the surface of steel bars, facilitating the formation of passivation films. TCPP primarily adsorbs onto active sites on the surface of the passivation film, where lattice iron ions have leached. The adsorbed TCPP accelerates the formation of the passivation film through ORR catalysis, inhibiting the development of passivation film defects and enhancing the integrity and protection of the passivation film. The most significant effect is observed when the concentration of TCPP is 0.5 mmol/L. The physical adsorption of TCPP is primarily determined by the negative charge centers, namely the carboxyl group O and the pyrrole N. However, due to steric hindrance caused by the unrestricted rotation of the carboxyl benzene, the pyrrole N does not play a dominant role in chemical adsorption. Instead, the active site for chemical adsorption is the carboxyl group O. The adsorption process significantly reduces the diffusion coefficient of TCPP molecules, providing a robust and stable adsorption binding. Phthalocyanine molecules without carboxyl benzene groups adopt a planar structure, allowing them to form stable adsorption configurations on the iron surface through flat adsorption. This observation provides guidance for the design of novel metal phthalocyanine molecules. Specifically, the development of metal phthalocyanine molecules with modifying groups that are coplanar with the phthalocyanine ring and possess restricted rotation can achieve flat adsorption, improve coverage rate, and enhance adsorption configuration stability.
研究领域:
材料科学
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腐蚀工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ruiqi Guo,Zhenglong Fan,Qiwei Zhou,Mengjie Ma,Wenxiang Zhu,Fan Liao,Hao Yang,Jiajie Wang,Zhenhui Kang,Minqi Sheng
Iridium oxide (IrO 2 ) has traditionally been considered to exhibit limited oxygen-reducing capacity. An effective approach to improve the oxygen reduction reaction (ORR) activity in parent catalytic materials is through atomic intercalation. However, the challenge lies in achieving a delicate balance between high ORR activity, structural stability, and minimizing the use of precious metals. Herein, we fabricate 3R-phase iridium oxide (3R-IrO 2 ) with superior ORR activity by intercalating a tiny amount of Pt (3.6 wt% Pt) into the interlayers of 3R-IrO 2 (3.6 wt% Pt-3R-IrO 2 ). When employed as an acidic ORR electrocatalyst, 3.6 wt% Pt-3R-IrO 2 shows a high half-wave potential (E 1/2 ) of 0.92 V (vs. RHE) in O 2 -saturated 0.1 M HClO 4 electrolyte, much better than those of Pt/C (0.850 V), 3R-IrO 2 (0.616 V), and Pt nanoparticles on 3R-IrO 2 surface (3.6 wt% Pt@3R-IrO 2 ) (0.618 V) electrocatalysts. It achieves high mass activity of 0.170 A mg Ir −1 at the potential of 0.9 V, which is 5.5 and 11.3 times than that of Pt/C (0.031 A mg Ir −1 ) and 3.6 wt% Pt@3R-IrO 2 (0.015 A mg Ir −1 ), respectively. Density functional theory (DFT) calculations and experiment results co-jointly demonstrate that the active center of Pt-3R-IrO 2 is anchored to the activated Ir atoms of the 3R-IrO 2 rather than Pt atoms. The d -band center of Ir 5 d orbitals of Pt-3R-IrO 2 is simultaneously regulated, which optimizes the energy barrier of adsorption/desorption toward the ORR process. Intriguingly, the intercalation of Pt atoms into trigonal rhodium oxide (Tri-RhO 2 ) also activates the ORR activity of Rh, suggesting the universality of this strategy. This discovery may provide a new and general way for activation of ORR activity of other precious metal-intercalated nonprecious metal oxide electrocatalysts.
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
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 23
·8380
·
IF 3.748
Chen Chu,Jinqiong Tang,Zhiyang Zhao,Yong Kong,Xiaodong Shen
Aerogels have interconnected networks and preeminent pore structures. When used as the catalysts for oxygen reduction reaction (ORR), they can facilitate the mass transfer and expose more active sites. Here, we synthesized the Fe-doped titanium oxide-based aerogels (TA/Fes) by the sol–gel method combined with thermal treatment. The specific surface areas of the TA/Fes ranged from 475 to 774 m2·g−1, and the pore volumes varied from 0.96 to 1.72 cm3·g−1. The doping effect of the Fe ions and the oxygen vacancies in anatase enhance the electrical conductivity, leading to the low Rct (313.3–828.2 Ω). All samples showed excellent stability (2.0–4.5 mV) and 4e−pathway. The limiting current density of TA/Fe3 reached 5.34 mA·cm−2, which was comparable to that of commercial Pt/C. The preparation method is inspiring and the as-prepared aerogel catalysts have potential in promoting the scale of fuel cells.Keywords:TiO2aerogel;Fe ion doping;oxygen vacancy;pore structure;catalysis;ORR
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
CHEMISTRY-A EUROPEAN JOURNAL
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2024
·
IF 3.9
Tingting Xiang,Qingchao Zhu,Tanyu Zhou,Chenglong Chen,Ruibo Wang,Tieyu Hu,Bing Li,Ziwei Xu,Juan Yang
Graphical Fe−N−C catalysts, doped with phosphorus, show improved ORR activity. Fe-NPC catalyst exhibits high metal loading, excellent ORR performance (onset potential of 1.00 V, half-wave potential of 0.864 V), and promising application in Zn-air batteries (758.8 mAh g −1 Zn ). DFT calculations reveal that phosphorus enhances O 2 activation and reduces the energy barrier for the rate-determining step. Atomically dispersed iron and nitrogen co-doped carbon materials (Fe−N−C) represent promising non-precious metal catalysts for the oxygen reduction reaction (ORR), offering potential alternatives to noble metal-based benchmarks. In our study, we investigated the influence of phosphorus doping on the catalytic activity of Fe−N−C. The experimental research demonstrate that the doping of phosphorus significantly enhances the ORR activity. Specifically, the resulting Fe-NPC exhibits high metal loading and excellent ORR activity in 0.1 M KOH with an onset potential of 1.00 V and a half-wave potential of 0.864 V. Density functional theory (DFT) simulations reveal that phosphorus improves the electrocatalytic activity by activating O2 molecules and reducing the energy barrier (the hydrogenation reaction *OH→H2O) of the rate-determining step. Furthermore, Fe-NPC exhibits promising application prospects as an air cathode in Zn-air batteries, delivering a high maximum discharge power density of 180.3 mW cm −2 and outstanding discharge specific capacity (758.8 mAh g −1 Zn ) at a discharge current density of 10 mA cm −2 .
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Dilihumaer Taxi,Shujuan Shao,Xieraili Maimaitiyiming,Amatjan Sawut,Mamutjan Tursun,Zaituniguli Kuerban,He Lin
Oxygen reduction reaction (ORR), as an important reaction carried out on the cathode of direct methanol fuel cells (DMFC), directly affects the performance of the cell. Previous experimental studies have shown that there are some interactions between the defect structure and N doping to promote the ORR performance of the catalysts. In this work, the binder was first utilized to reduce the lignin content in the cotton straw (CS) system, thereby increasing the defective structure of the carbon substrate. Here, we obtained 5C-NP-Fe catalysts by increasing the defectivity of the carbon substrate through binder. The coordination environment surrounding the Fe-N 4 sites is optimized by the synergistic action of the N and P atoms and the faulty structure, as shown by DFT theoretical calculations. In alkaline medium, half-wave potentials as high as 0.88 V in the three-electrode system and a peak power density of 10.8 mW cm −2 in a direct methanol fuel cell at 60℃. Compared to a 20 wt% commercial Pt/C catalyst (0.84 V, 7.5 mW cm −2 ), 5C-NP-Fe showed good ORR activity. The binder modification strategy provides a simple and green approach to the structural optimization of biomass-based catalysts.
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Huajing Li,Juanjuan Yin,Yuting Meng,Shufeng Liu,Tifeng Jiao
With the advancement of society, the energy and environmental crisis is particularly prominent. Therefore, the development of efficient, stable and inexpensive catalysts for oxygen reduction reactions (ORR) is critical for many technologies such as fuel cells and metal-air batteries. Herein, we report a hydrogel polymerization strategy to synthesize a nickel-containing polypyrrole hydrogel (NiPcTs/PPy hydrogel). The nickel/cobalt-containing PPy hydrogel (NiPcTs/Co/PPy hydrogel) can be getting after immersing the NiPcTs/PPy hydrogel in Co 3+ aqueous solution. Furthermore, the pyrolyzed product of NiPcTs/Co/PPy hydrogel is a kind of efficiently active ORR catalysts. Although the NiPcTs/Co/PPy catalyst exhibits a similar catalytic activity compared to commercial Pt/C (20%) on the basis of the initial voltage, it shows a similar diffusion-limiting current density compare to Pt/C within the applied potential range. It is worth to mention that the cost of the NiPcTs/Co/PPy catalyst is much lower. This work provides a new strategy for the development of highly active and non-precious metal based electrocatalysts for electrochemical energy devices.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Batteries-Basel
·
2022
·Vol. 8
·期 12
·259
·
IF 5.938
Kaixin Li,Zhanhua Dong,Zhe Lü
The development of robust and efficient electrocatalysts for use in fuel cells and metal–air batteries has garnered a great deal of interest due to the quest for clean and renewable energy sources. In this paper, a promising Co-doped Pr0.5Ba0.4Ca0.1Fe1-xCoxO3-δ(x = 0, 0.2, 0.4, 0.6, 0.8; denoted as PBCFC-x, x = 0, 2, 4, 6, 8) with enhanced durability and electrocatalytic ORR/OER activity for zinc–air battery cathode catalysts is presented. Particularly, PBCFC-6 exhibits the best bifunctional catalytic activity in alkaline media among several materials, according to research using the RDE. The zinc–air battery with PBCFC-6 as the cathode catalyst delivered the smallest discharge–charge voltage difference at the current density of 10 mA·cm−2and only increased by 0.031 V after 220 cycles (220 h), demonstrating its superior bifunctional catalytic activity and durability. The optimized electrochemical performance of both OER and ORR as well as stability in zinc–air batteries might result from the higher electrical conductivity, increasing concentration of adsorbed oxygen, and the greater proportion of Fe4+(t2g3eg1) with optimal electron occupancy, owing to the partial replacement of Fe with Co.Keywords:Pr0.5Ba0.4Ca0.1Fe1-xCoxO3-δ;rechargeable zinc–air batteries;ORR/OER;bifunctional catalyst
研究领域:
材料科学
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电化学
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能源技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）