APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
·
IF 24.319
Shaomian Liu,Wenjuan Xue,Yongjun Ji,Wenqing Xu,Wenxing Chen,Lihua Jia,Tingyu Zhu,Ziyi Zhong,Guangwen Xu,Donghai Mei,Fabing Su
Simultaneously improving both NO x conversion and N 2 selectivity in the selective catalytic reduction of NO by CO (CO-SCR) under O 2 -containing conditions is highly challenging because of the competitive reactions of NO x and CO with O 2 . Here, we demonstrate that the interfacial oxygen vacancies (IOVs) generated at the Co 3 O 4 -CeO 2 heterointerfaces by ball-milling-induced strain can remarkably boost both NO x conversion and N 2 selectivity in the temperature range of 100–400 °C. The Co 3 O 4 -CeO 2 -IOV catalyst achieved approximately 100% NO x conversion and 100% N 2 selectivity (200–350 °C, 1–5 vol% O 2 , and 20,000 h −1 ); even under 10 vol% O 2 , it still showed good catalytic performance. The spectroscopy analysis and theoretical calculations reveal that compared with O 2 activation, IOVs are more favorable for the rate-limiting step of NO adsorption and dissociation. This work provides an effective strategy to create IOVs within metal oxide composite catalysts using ball-milling-induced interfacial strain for improving CO-SCR performance.
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高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 11
·1801-1814
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IF 11.534
Cheng Fuhao,Zhang Fengnian,Liu Yufeng,Guo Meng,Cheng Chufei,Hou Jiadong,Miao Yang,Gao Feng,Wang Xiaomin
Environmental barrier coatings (EBCs) with excellent chemical resistance and good high-temperature stability are of great significance for their applications in next-generation turbine engines. In this work, a new type of high-entropy fluorite-structured oxide (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 )O 2− δ (HEFO-1) with different Ti 4+ contents were successfully synthesized. Minor addition of Ti 4+ could be dissolved into a high-entropy lattice to maintain the structure stable, effectively reducing the phase formation temperature and promoting the shrinkage of bulk samples. Heat treatment experiments showed that all the samples remained a single phase after annealing at 1200–1600 °C for 6 h. In addition, high-entropy (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 Ti 0.2 x )O 2− δ demonstrated great resistance to calcium—magnesium—alumina—silicate (CMAS) thermochemical corrosion. When the content of Ti was increased to x = 0.5, the average thickness of the reaction layer was about 10.5 after being corroded at 1300 °C for 10 h. This study reveals that high-entropy (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 Ti 0.2 x )O 2− δ is expected to be a candidate for the next-generation EBC materials with graceful resistance to CMAS corrosion.
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MOLECULES
·
2022
·Vol. 27
·期 17
·5576
·
IF 4.927
Songtao Liu,Rui Yan,Muhammad Humayun,Huanli Zhang,Yang Qu,Yingxue Jin
It is highly desired to enhance charge separation and O2adsorption of the pyropheophorbide-a (Ppa) to promote visible-light activity and stability. Herein, Ppa modified 001-facet-exposed TiO2nanosheets (Ppa/001T) nanocomposites with different weight ratios were fabricated via the self-assembly approach by OH induced. Compared with the bare Ppa, the 8% amount optimized 8Ppa/001T sample displayed 41-fold enhanced activity for degradation of Ametryn (AME) under visible-light irradiation. The promoted photoactivities could be attributed to the accelerated charge carrier’s separation by coupling TiO2as thermodynamic platform for accepting the photoelectrons with high energy from Ppa and the promoted O2adsorption because of the residual fluoride on TiO2. As for this, a distinctive two radicals (•O2−and •OH) involved pathway of AME degradation is carried out, which is different from the radical pathway dominated by •O2−for the bare Ppa. This work is of utmost importance since it gives us detailed information regarding the charge carrier’s separation and the impact of the radical pathway that will pave a new approach toward the design of high activity visible-light driven photocatalysts.Keywords:Ppa;001-facet-exposed TiO2;charge separation;visible-light photocatalysis;Ametryn
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PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
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2022
·
IF 11.322
Xinbin Wu,Wei Yu,Wei Xu,Yujun Zhang,Shundong Guan,Zheng Zhang,Shuwei Li,Huanchun Wang,Xuanjun Wang,Liang Zhang,Ce-Wen Nan,Liangliang Li
Lithium-oxygen (Li–O 2 ) batteries are promising next-generation energy storage devices due to their ultrahigh theoretical specific energy. Oxide electrocatalysts such as RuO 2 are often used to improve the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) processes in Li–O 2 batteries, but the relation between the structural parameters and their catalytic properties is unclear so far. In this work, we synthesize RuO 2 nanoparticles at different annealing temperatures and investigate the influence of the Ru–O bond distances of RuO 2 on the OER and ORR processes in Li–O 2 batteries. The results of X-ray absorption fine structure show that the bond distances decrease with the increase of the annealing temperature. The RuO 2 with longer Ru–O bond distances renders a lower charge plateau to Li–O 2 batteries, showing a better OER performance, while that with shorter bond distances gives a larger discharge capacity and is more friendly to the ORR process. The cycle life of Li–O 2 batteries with a carbon nanotube-RuO 2 composite cathode is improved to 287 cycles (1148 h) under an extreme testing condition (the voltage range is 2.3–4.2 V), when the Ru–O bond distances are optimized. In addition, the influence of the Ru–O bond distances on the catalytic properties of RuO 2 is analyzed by density functional theory calculations. The findings in this work provide a guidance to enhance the ORR and OER efficiency of RuO 2 and other oxide catalysts.
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2021
·Vol. 38
·期 1
·200-208
·
IF 1.307
Wang Yue,Wang Xiaoxue,She Ping,Guan Dehui,Song Lina,Xu Jijing
D esign and fabrication of functional porous air cathode materials with superior catalytic activity is still the key point for non-aqueous lithium-oxygen(Li-O 2 ) batteries. Herein, inspired by the self-standing three-dimensional(3D) structure of the natural spinach leaves, a unique binder-free and self-standing porous Au/spinach cathode for high-performance Li-O 2 batteries has been developed. The carbonized spinach leaves serve as a superconductive current collector and an ideal porous host for accommodating catalysts. The Au/spinach cathode could offer enough spaces for accommodating the discharge products, shorten the distance of the oxygen and electrolyte diffusion, and promote the oxygen reduction reaction(ORR) and oxygen evolution reaction (OER) processes. This optimized Au/spinach cathode achieved a high specific area capacity of 7.23 mA·h/cm 2 at a current density of 0.05 mA/cm 2 and exhibited excellent stability(280 cycles at 0.05 mA/cm 2 with a fixed capacity of 0.2 mA·h/cm 2 ). The superior performance encourages the construction of more advanced cathode architectures by the use of bio-composites for Li-O 2 batteries.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Zhengyi Qian,Xudong Li,Liguang Wang,Tianpin Wu,Baoyu Sun,Lei Du,Yulin Ma,Chunyu Du,Pengjian Zuo,Geping Yin
Rechargeable aprotic Li–O2 batteries have drawn much attention in light of their ultrahigh theoretical energy density. However, the sluggish kinetics of oxygen cathode reactions lead to huge energy loss, while the unfavorable side reactions associated with the widely used carbon and binder account for fast battery decay during cycles. Herein, hierarchically holey IrNi alloy nanosheets are facilely designed on Ni foam substrate as a freestanding, binder- and carbon-free cathode to address these challenges. The IrNi nanosheets consist of numerous interconnected nanoparticles, forming abundant nanoholes, benefiting active-site exposure. Moreover, the meso-/macropores pave channels for the transfer of oxygen and lithium ions and provide enough accommodation for the insoluble Li2O2 product. The corresponding Li–O2 batteries demonstrate low polarization and excellent cycle stability with full discharge/charge capability (up to 292 cycles at a current density of 0.2 mA cm–2 within a voltage range from 2.3 to 4.3 V). The long-term cycling performance is principally attributed to the exclusive catalytic stability of the holey IrNi nanosheets and its good compatibility with dimethyl sulfoxide-based electrolyte. Our research provides novel insights into the design of robust and freestanding porous cathodes for high energy density Li–O2 batteries.
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高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Jia Liu,Ying Wang,Dan Zhou,Dan Li,Ziye Kang,Haiming Xie
Although a redox mediator (RM) strategy can lower the overpotential of Li–O2 batteries (LOBs), the redox shuttling results in an undesired RM consumption and a continued decomposition of lithium metal anode, leading to a poor cycling stability. In this work, a hybrid inorganic–organic composite separator based on polyethylene oxide/TiO2/polypropylene (PEO/TiO2/PE) in LOBs has been reported for the first time, which aims to suppress the RM shuttling. The influences of TiO2 nanoparticles and PEO on battery performance are systematically investigated. Benefiting from the synergistic advantages, a LOB with PEO/TiO2/PE separator displays stable cyclability, considerable rate performance, and good reversibility. Additionally, the mechanism of inhibiting shuttling effect by this composite separator is proposed. We hope that this work can give an insight into the development of multiple functional separators for Li anode protection in LOBs.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Wenjing Shen,Dandan Xiang,Junnan Yang,Yanting Tang,Changhui Xin,Quanhui Guo,Xin Yu
In this work, beta zeolite supported Ti 3+ -TiO 2 /CdS heterojunction was prepared for photodegradation of tetracycline under visible-light irradiation, and zeolite served as a support for the high dispersions of the Ti 3+ -TiO 2 nanoparticles . The obtained zeolite/Ti 3+ -TiO 2 /CdS heterojunction showed a relatively high surface areas of approximately 63.2 m 2 g −1 , much higher than those of the prepared Ti 3+ -TiO 2 /CdS (27.1 m 2 g −1 ), Ti 3+ -TiO 2 (36.5 m 2 g −1 ), and CdS (31.1 m 2 g −1 ), strongly demonstrating the significant of zeolite for high dispersion of the Ti 3+ -TiO 2 /CdS composite. Besides, the experimental results also showed that the photocatalytic degradation efficiency could reach 78 % in 3 min for the zeolite/Ti 3+ -TiO 2 /CdS heterojunction, and the corresponding rate constant was as high as 0.788 min −1 , which was 26.90 times that of pristine Ti 3+ -TiO 2 , 2.24 times of pristine CdS , and 2.04 times of the Ti 3+ -TiO 2 /CdS composite, mainly because of the supporting effects of zeolite and the formation of Ti 3+ -TiO 2 /CdS heterostructure for highly enhanced charge separation. In addition, the trapping experiment revealed that the main reactive species involved in tetracycline degradation were attributed to the photo-generated holes and ⸱O 2 - species.
研究领域:
环境科学
·
材料科学
·
化学
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高影响因子
Science Bulletin
·
2024
·
IF 18.8
Zhihong Bi,Anping Zhang,Gongrui Wang,Cong Dong,Pratteek Das,Xiaoyu Shi,Zhong-Shuai Wu
High-voltage and fast-charging LiCoO 2 (LCO) is key to high-energy/power-density Li-ion batteries. However, unstable surface structure and unfavorable electronic/ionic conductivity severely hinder its high-voltage fast-charging cyclability. Here, we construct a Li/Na-B-Mg-Si-O-F-rich mixed ion/electron interface network on the 4.65 V LCO electrode to enhance its rate capability and long-term cycling stability. Specifically, the resulting artificial hybrid conductive network enhances the reversible conversion of Co 3+/4+ /O 2−/ n − redox by the interfacial ion–electron cooperation and suppresses interface side reactions, inducing an ultrathin yet compact cathode electrolyte interphase. Simultaneously, the derived near-surface Na + /Mg 2+ /Si 4+ -pillared local intercalation structure greatly promotes the Li + diffusion around the 4.55 V phase transition and stabilizes the cathode interface. Finally, excellent 3 C (1 C = 274 mA g −1 ) fast charging performance is demonstrated with 73.8% capacity retention over 1000 cycles. Our findings shed new insights to the fundamental mechanism of interfacial ion/electron synergy in stabilizing and enhancing fast-charging cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
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高影响因子
Nano Research
·
2020
·Vol. 13
·期 12
·3292-3298
·
IF 8.183
Wei Pengkun,Hao Zewei,Yang Yang,Liu Mingyang,Zhang Haijun,Gao Min-Rui,Yu Shu-Hong
Although nickel-based catalysts display good catalytic capability and excellent corrosion resistance under alkaline electrolytes for water splitting, it is still imperative to enhance their activity for real device applications. Herein, we decorated Ni 0.85 Se hollow nanospheres onto reduced graphene oxide (RGO) through a hydrothermal route, then annealed this composite at different temperatures (400 °C, NiSe 2 -400 and 450 °C, NiSe 2 -450) under argon atmosphere, yielding a kind of NiSe 2 /RGO composite catalysts. Positron annihilation spectra revealed two types of vacancies formed in this composite catalyst. We found that the NiSe 2 -400 catalyst with dual Ni-Se vacancies is able to catalyze the oxygen evolution reaction (OER) efficiently, needing a mere 241 mV overpotential at 10 mA·cm −2 . In addition, this catalyst exhibits outstanding stability. Computational studies show favorable energy barrier on NiSe 2 -400, enabling moderate OH − adsorption and O 2 desorption, which leads to the enhanced energetics for OER.
研究领域:
材料科学
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电化学
·
催化
·
纳米技术
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高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Liying Hao,Jikui Sun,Qingyin Wang,Haijiao Xie,Xiangui Yang,Qiang Wei
As an atom-economical reaction, the direct generation of dimethyl carbonate (DMC) and ethylene glycol (EG) via the transesterification of CH3OH and ethylene carbonate (EC) has several promising applications, but the exploration of carriers with high specific surface areas and novel heterogeneous catalysts with more basic sites remains a long-standing research challenge. For this purpose, herein, a nitrogen-doped mesoporous carbon (NMC, 439 m2/g) based K–O2 Lewis base catalyst (K–O2/NMC) with well-dispersed strongly basic sites (2.23 mmol/g, 84.5%) was designed and synthesized. The compositions and structures of NMC and K–O2/NMC were comprehensively investigated via Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, CO2 temperature-programmed desorption, and contact angle measurements. The optimal structural configuration and electron cloud distribution of the K–O2/NMC catalyst were simulated using first-principles calculations. The electron transfer predominantly manifested as a flow from K–O to C–O/C–N, and the interatomic interactions between each atom were enhanced and exhibited a tendency for a more stable state after redistribution. Furthermore, the adsorption energies (Eads) of CH3OH at K–O–O and K–O–N sites were −1.4185 eV and −1.3377 eV, respectively, and the O atom in CH3OH exhibited a stronger adsorption tendency for the K atom at the K–O–O site. Under the optimal conditions, the EC conversion, DMC/EG selectivity, and turnover number/frequency were 80.9%, 98.6%/99.4%, and 40.5/60.8 h–1, respectively, with a reaction rate constant (k) of 0.1005 mol/(L·min). Results showed that the heterogeneous K–O2/NMC catalyst prepared herein greatly reduced the reaction cost while guaranteeing the catalytic effect, and the whole system required a lower reaction temperature (65 °C), a shorter reaction time (40 min), and a lower catalyst amount (2.0 wt % of EC). Therefore, K–O2/NMC can be used as a catalyst in different transesterification reactions.
研究领域:
催化化学
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材料科学
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绿色化学
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PubMed
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Renjie Deng,Huajie Liu,Haishuai Cui,Yao Tian,Hai Yang
In this work, we have developed a green method for the preparation of para-nitrotoluene through the catalytic nitration of toluene with nitrogen dioxide (NO2) under the promotion of dioxygen (O2). The experimental results reveal that the dealumination of Hβ zeolite has a significant effect on the catalysis of the developed NO2–O2–acetic anhydride (Ac2O) system, in which the conversion of toluene is 78.1% and the selectivity to para-nitrotoluene is 71.8%. Furthermore, the nature of different dealuminated catalysts was investigated by nitrogen adsorption–desorption analysis, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), thermal gravimetric analysis (TGA), inductively coupled plasma (ICP), ammonia temperature-programmed desorption (NH3-TPD), pyridine adsorbed Fourier-transform infrared (Py-FT-IR), scanning electron microscopy (SEM) and 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR) techniques. The results of characterization indicate that the structure of the Hβ zeolite still remains and that of Al species in the extra-framework is preferentially removed after acid treatment. Based on the combined results of catalytic characterization and DFT calculation, a feasible reaction mechanism of improved para-selectivity in toluene nitration was suggested for the NO2–O2–Ac2O system.
研究领域:
催化化学
·
材料科学
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高影响因子