ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Yuan Chen,Xu Zhang,Shixiang Feng
Contributions of excited triplet state of humic acid (3HA*) and superoxide radical anion (O2•–), which is mainly generated via the reaction of O2 with HA-derived reducing intermediates (HA•–), to phenol transformation were revealed using acetaminophen, 2,4,6-trimethylphenol and tyrosine as probe molecules. Phenol transformation was initiated by 3HA*, leading to the formation of the phenoxyl radical (PhO•), but the distribution of transformation intermediates was codetermined by 3HA* and HA•–. The influence of HA•– essentially resulted from the production of O2•–, which affected the fate of PhO•. PhO• could undergo dimerization, or react with O2•–, leading to either phenol peroxide formation (radical addition) or phenol regeneration (electron transfer). In addition, PhO• could bind to HA or react with HA radicals, particularly in the absence of O2 and O2•–. These PhO• reactions were dependent on the reduction potential and structure of PhO•. This study also proved that the reaction of phenol with 1O2 and the reaction of PhO• with O2•– lead to the same oxidation product. The contributions of 3HA* and its generated 1O2, HA•– and its generated O2•– to phenol transformation were pH-dependent.
研究领域:
环境化学
·
物理化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2025
·
IF 4.2
Yu-Le Wang,Songhai Wu,Yu-Zhen Xu,Yu-Dong Shan,Yong Liu,Xu Han
The selective oxidation of cyclohexene (Cy) to cyclohexene oxide (Cy-ep) using O2 remains challenging due to low epoxidation selectivity. In this work, a series of Mo-doped TS-1 (Mo-TS-1) catalysts were successfully synthesized for the epoxidation of Cy under solvent- and initiator-free conditions with O2 as the oxidant. Among them, 5Mo-TS-1 exhibited high catalytic performance, achieving 43.5% Cy conversion and 50.6% selectivity toward Cy-ep. Additionally, valuable byproducts such as 2-cyclohexen-1-ol (Cy-ol) and 2-cyclohexen-1-one (Cy-one) were obtained with yields of 28.0% and 21.4%, respectively. Since both Cy-ol and Cy-one are valuable intermediates in fragrance synthesis, over 43.5% of Cy was effectively converted into high-value products. Quenching experiments and Raman spectroscopy revealed that surface oxygen vacancies (Ov) facilitate the activation of O2 to form ≡Ov‑superoxo species, which abstract hydrogen from the allylic C-H bond of Cy to generate 3-cyclohexenyl radicals (Cy•). These radicals subsequently react with O2 to form Cy-OO•, followed by hydrogen abstraction from another Cy molecule to yield 2-cyclohexene-1-hydroperoxide (Cy-OOH). A positive correlation between Cy-OOH and Cy-ep formation underscores the critical role of Cy-OOH in the epoxidation process. Furthermore, Raman spectroscopy confirmed the presence of ≡Mo-(η2-O2) peroxo species on the catalyst surface, which preferentially attack the C=C bond of Cy to form Cy-ep. DFT calculations elucidated two distinct O2 activation pathways: In Pathway I, O2 is activated at Ov sites to form ≡Ov‑superoxo, which subsequently reacts with Cy to generate ≡Ov‑peroxo, Cy-OOH, and Cy•. In Pathway II, Mo(V/VI) sites either directly activate O2 or react with peroxo intermediates (≡Ov‑peroxo or Cy-OOH) to form ≡Mo-(η2-O2). This species selectively epoxidizes the alkene bond in Cy to Cy-ep. Notably, the direct activation of O2 at Mo(V/VI) sites bypasses the allylic oxidation route, thereby enhancing the epoxidation selectivity beyond the theoretical limit of 50.0%. This study provides new insight on the importance of surface superoxo and peroxo mediated by Ov and Mo(V/VI) in the epoxidation processes.
研究领域:
催化化学
·
材料化学
·
绿色化学
·
多相催化
·
氧化反应
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Yang Zhan,Shun-zhi Yu,Shao-hua Luo,Jian Feng,Qing Wang
Transition-metal sulfides (TMS) are one of the most promising cathode catalysts for Li–O2 batteries (LOBs) owing to their excellent stabilities and inherent metallicity. In this work, a highly efficient mode has been used to synthesize Co@CNTs [pyrolysis products of metal–organic frameworks (MOFs)]-derived CoS2(CoS)@NC. Benefiting from the special yolk–shell hierarchical porous morphology, the existence of Co–N bonds, and dual-function catalytic activity (ORR/OER) of the open metal sites contributed by MOFs, the CoS2@NC-400/AB electrode illustrated excellent charge–discharge cycling for up to nearly 100 times at a current density of 0.1 mA cm–2 under a limited capacity of 500 mA h g–1 (based on the total weight of CoS2@NC and AB) with a high discharge voltage plateau and a low charge cut-off voltage. Meanwhile, the average transferred electron number (n) is around 3.7 per O2 molecule for CoS2@NC-400, which is the chief approach for a four-electron pathway of the ORR under alkaline media. Therefore, we believe that the novel CoS2@NC-400/AB electrode could serve as an excellent catalyst in the LOBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Ziling Wang,Xianzhu Peng,Shuai Guo,Mingjie Sun,Junfang Cheng,Lu Zou,Bo Chi,Jian Pu
Catalysts with high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performances are crucial to the development of lithium-oxygen batteries (LOBs), which aim to promote Li2O2 deposition and decomposition and then avoid the active site passivation. Considering the metallic Ag possessing good electrical conductivity and excellent catalytic activity and perovskite oxides exhibiting high abundance, an easily tunable structure, and excellent intrinsically catalytic activity, we adopt the ultraviolet light to realize the deposition of Ag nanoparticles on the La0.6Sr0.4Fe0.9Mn0.1O3 (LSFM) substrate as a high-performance cathode for LOBs. The results confirm that the synergetic effect of Ag nanoparticle decoration and the La0.6Sr0.4Fe0.9Mn0.1O3 substrate could dramatically improve the electronic conductivity and ORR/OER kinetics of the nanohybrids. Ag@LSFM hybrids with abundant active sites and considerable electronic conductivity promote the deposition of a thinner discharge product film, and the corresponding LOBs deliver high discharge capacity (12 477 mAh g–1), a small gap between charge and discharge potentials (∼1.3 V), and high cycling stability (147 cycles). Overall, the study suggests that such a bifunctional catalyst is a promising candidate in LOBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 24
·8445-8457
·
IF 5.721
Kun Liu,Yichen Zhao,Jiale Wang,Qingsong Xue,Guofeng Zhao
The fabrication of qualified catalysts is a key issue to implement gas-phase aerobic alcohol oxidation but necessarily requires understanding the structures of catalytic active sites and the supply of active oxygen species. Herein, we present one example of the Ag–CoO/Ti- powder catalyst for gas-phase benzyl alcohol aerobic oxidation. The first interesting observation is that the Ag–Co3O4 ensembles on the fresh catalyst could be transformed into Ag–CoO due to the presence of reductive benzyl alcohol. The preferred catalyst with 3 wt% Ag and 3 wt% CoO exhibits 93% benzyl alcohol conversion and 99% benzaldehyde selectivity at a weight hourly space velocity of 20 h−1 and a temperature of 240 °C. The structures of Ag–CoO ensembles and oxygen species supply were probed and identified by electron microscopy and other spectroscopy techniques in combination with temperature-programmed thermal analyses, pulse experiments, and kinetic studies. In nature, the oxygen species is generated at the Ag–CoO interfacial sites in the form of atomic oxygen with appropriate chemisorption strength on these sites to achieve a high oxidation activity of benzyl alcohol. Moreover, the Co3O4 ↔ CoO cycle is promoted by Ag at low temperature such as 240 °C to endow the Ag–CoO ensembles with excellent catalytic performance.
研究领域:
催化化学
·
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2019
·
IF 3.782
Song Hongbing,Liu Zong,Gai Hengjun,Wang Yongjie,Qiao Lin,Zhong Caiyun,Yin Xiangyang,Xiao Meng
Introducing electron-rich nitrogen atoms to ordered mesoporous carbons (OMC) as supports for noble metal catalysts, not only improves the hydrophilic properties of a mesoporous carbon surface, but also enhances the coordination and binding abilities of metal ion. In the present work, nitrogen-doped ordered mesoporous carbons (NOMCs) were successfully fabricated via a facile hydrothermal self-assembly. The prepared NOMCs were characterized through powder X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption isotherm. The analyses demonstrated that the NOMCs prepared at a pyrolysis temperature of 750°C possessed an ordered 2D hexagonal mesoporous structure, a high graphitization degree, large surface area, and a well-distributed pore size. In particular, NOMCs could anchor Pd nanoparticles uniformly because of the introducing N atoms with strong electronegativity, which were selected as efficient catalysts for the partial oxidation of benzyl alcohol to benzaldehyde. Approximately 24.63% conversion with 85.71% selectivity to benzaldehyde was obtained without using any solvent by molecular O2 oxidation. Most importantly, the TOF value of the catalyst in the reaction system was up to 8698 h−1. After five runs reaction, TOF and selectivity of the catalyst remained essentially same. Hence, the proposed catalyst has a potential engineering application value.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Feng Li,Yuhang Tian,Yanyun Sun,Peiyu Hou,Xianqi Wei,Xijin Xu
High-voltage and low-cost manganese-based P 2-type oxides show real promise as promising cathode for sodium-ion batteries (SIBs). But the P 2 − O2 phase transformation and Na + /vacancy ordering results in the inferior structural stability and Na + diffusion coefficient , which further leads to rapid decay of capacity and poor rate capability. Herein, in consideration of the synergetic effects of dual cationic doping, electrochemically inactive Li + and active Co 3+ codoping are proposed to solve the above issues. The novel two-step doping strategy, Co doping during synthesis of precursors via coprecipitation reaction followed by Li doping during solid-state reaction, are rationally developed. As anticipated, the Li/Co codoped P 2-type oxide exhibits the absence of P 2 − O2 phase transformation and Na + /vacancy disordering, which gives rise to an outstanding cycling stability (86.7% capacity retention within 100 cycles at 0.1C) and high-rate capability (reversible capacity of 109 mAh g −1 even at 10C). In addition, the full-cells composed of the codoped P 2-type positive and hard carbon negative show high energy-density, good lifespan and high-rate property. This proposed cationic codoping provides an effective and scalable tactics for modulating the structural properties of high-voltage P 2-type cathodes for advanced SIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2017
·Vol. 34
·期 12
·3132-3141
·
IF 2.007
Zhang Wei,Li Xin,Wang Hong,Song Yongji,Zhang Shenghong,Li Cuiqing
Deep desulfurization of model oil by photocatalytic air oxidation and adsorption using Ti (1− x ) M
x
O 2 (M=Zr, Ce) was investigated. Ti (1− x ) M
x
O 2 (M=Zr, Ce) was prepared by urea gelation/co-precipitation method, and characterized by N 2 adsorption, XRD and UV-vis spectra. UV irradiation greatly enhanced the adsorptive capacity and selectivity of TiO 2 -ZrO 2 for organosulfur in model oil because organosulfur compounds were first photocatalytically oxidized to sulfoxides and sulfones over TiO 2 -ZrO 2 , which were then selectively adsorbed on the bifunctional material due to much higher polarities of generated sulfoxides and sulfones. The Ti/Zr molar ratio and calcination temperature were optimized to 5 : 5 and 500 °C with the sulfur removal of 99.6% after reaction for 2 h under UV irradiation. After adding 25 wt% toluene into model oil, the sulfur removal could still reach 97.2% after reaction for 7 h. TiO 2 -ZrO 2 could be well regenrated by washing with acetonitrile followed by thermal treatment in air.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yuan Meng,Jianguo Jiang,Aikelaimu Aihemaiti,Tongyao Ju,Yuchen Gao,Jiwei Liu,Siyu Han
Amine-functionalized sorbents are investigated widely for CO2 capture from flue gas, to mitigate the crisis of global CO2 emission, with the advantages of excellent adsorption and regeneration performance. However, the presence of O2 in flue gas (3–10%) would induce the degradation of the sorbents, and some previous works proposed the strategies at the sacrifice of partial CO2 adsorption capacity. Herein, we focused on the oxidation behavior of PEI-functionalized silica in the long-term operation and analyzed the degradation mechanism by characterizing the oxidized sorbents. The sorbent proved to be oxidative stable under a lower temperature of air exposure, but the oxidative degradation would indeed occur at more harsh temperatures (above 90 °C). This study demonstrated that CO2 capture from O2-containing flue gas was feasible by controlling the operating temperature (below 75 °C), and the effective capacity of above 135 mg/g could be maintained in the cyclic CO2 capture.
研究领域:
环境科学
·
化学工程
·
碳捕集与封存（CCS）
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Qiong Yang,Peng-Fei Wang,Jin-Zhi Guo,Zi-Ming Chen,Wei-Lin Pang,Ke-Cheng Huang,Yu-Guo Guo,Xing-Long Wu,Jing-Ping Zhang
As a promising cathode material of sodium-ion battery, P2-type Na2/3Ni1/3Mn2/3O2 (NNMO) possesses a theoretically high capacity and working voltage to realize high energy storage density. However, it still suffers from poor cycling stability mainly incurred by the undesirable P2–O2 phase transition. Herein, the electrochemically active Fe3+ ions are introduced into the lattice of NNMO, forming Na2/3Ni1/3Mn2/3–xFexO2 (x = 0, 1/24, 1/12, 1/8, 1/6) to effectively stabilize the P2-type crystalline structure. In such Fe-substituted materials, both Ni2+/Ni4+ and Fe3+/Fe4+ couples take part in the redox reactions, and the P2–O2 phase transition is well restrained during cycling, as verified by ex situ X-ray diffraction. As a result, the optimized Na2/3Ni1/3Mn7/12Fe1/12O2 (1/12-NNMF) has a long-term cycling stability with the fading rate of 0.05% per cycle over 300 cycles at 5 C. Furthermore, the 1/12-NNMF delivers excellent rate capabilities (65 mA h g–1 at 25 C) and superior low-temperature performance (the capacity retention of 94% at −25 °C after 80 cycles) owing to the enhanced Na diffusion upon Fe doping, which is deduced by the studies of electrode kinetics. More significantly, the 1/12-NNMF also displays remarkable sodium-ion full-cell properties when merged with an LS–Sb@G anode, thus implying the possibility of their practical application.
研究领域:
材料科学
·
电化学
·
能量存储
·
电池技术
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
W.S. Huo,H. Zeng,Y. Yang,Y.H. Zhang
Enzymatic electrodes over-coated by thin film of nano-composite made up of polymer and functionalized nano-gold particle was prepared. Glucose/O 2 membrane-free enzymatic fuel cell based on nano-composite based electrodes with incorporated glucose oxidase and laccase was assembled. This enzymatic fuel cell exhibited high energy out-put density even when applied in human serum. Catalytic cycle involved in enzymatic fuel cell was limited by oxidation of glucose occurred on bioanode resulting from impact of sophisticated interaction between active site in glucose oxidase and nano-gold particle on configuration of redox center of enzyme molecule which crippled catalytic efficiency of redox protein.
研究领域:
生物化学
·
纳米生物学
·
能源科学
✓ 已验证
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 5
·459
·
IF 4
Dan Wang,Yanan Liu,Kun Wan,Danning Feng,Yan Pei,Minghua Qiao,Xiaoxin Zhang,Baoning Zong
The electrocatalytic reduction of O2via two-electron reaction (2e-ORR) to H2O2represents a promising alternative to the current anthraquinone process, since it is advantageous in the sustainable and decentralized production of H2O2. Herein, we report the development of oxygen and nitrogen-rich few-layered graphene-like materials (ms-dcda) by the one-step carbonization of biomass-sourced monosaccharides (D-glucose, D-fructose, D-galactose, D-ribose, D-xylose, L-arabinose, and D-mannose) with the aid of dicyandiamide for electrochemical O2reduction to H2O2. The ms-dcdamaterials were porous and possessed wrinkled morphology typical of graphene nanosheets. In H2O2production via 2e-ORR in an acidic electrolyte, these ms-dcdamaterials were all active and stable catalysts, among which glu-dcdaderived from D-glucose and dicyandiamide displayed the lowest onset potential of 0.553 V and the highest selectivity of up to 91.6%. The catalyst was also highly stable in chronoamperometric tests. Selective chemical titration of the C–OH and C=O groups revealed that the latter is far more active and selective than the former in 2e-ORR. Moreover, a positive correlation between the contents of C=O and pyrrolic N and the H2O2partial current suggests that the pyrrolic N group also contributes to 2e-ORR. This work affords a facile strategy for the sustainable fabrication of metal-free carbon-based catalysts efficient for H2O2electrosynthesis.
研究领域:
材料科学
·
电化学
·
催化
✓ 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）