CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Yangyang Tang,Zhongtian Du,Meijin Li,Wanhui Wang,Yonghou Xiao
Catalytic oxidation of alcohols containing heteroatoms with molecular oxygen is usually rather challenging, as transition metal catalysts are easily deactivated by heteroatoms. In contrast to conventional results, herein facile oxidation of 2-pyridinemethanol with dioxgyen was observed over simple vanadium catalysts including VOSO 4 or VO(acac) 2 , which seemed much easier than that of benzyl alcohol. 2-Pyridinemethanol could coordinate with the vanadium center , which would promote oxidation of 2-pyridinemethanol itself, rather than deactivate vanadium catalysts. This study would provide a new clue to develop efficient catalysts for transformations of heterocyclic compounds .
研究领域:
催化化学
·
有机化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Tianlong Liu,Peiyan Yang,Luyao Shen,Zhonghong Li,Yancheng Hu,Qi Li,Xiaobo Feng,Xiaoyan Zhao,Jingpei Cao
Alkaline oxidation is one of the methods for effective delignification of biomass and structural degradation of lignin. The depolymerized lignin has great potential to be valorized by hydrothermal gasification while little attempts have been made. The present authors subjected an alkaline lignin to oxygen oxidation in Na 2 CO 3 solution and investigated gasification performance of the lignin with a continuous flow reactor. The oxidative treatment decreased the molecular weight of lignin and produced large portions of acid-soluble fractions with a lower molecular weight. The depolymerized lignin was near-completely converted to H 2 , CH 4 and CO 2 at 340 °C with a Ru/C catalyst. The Ru/C catalyst maintained its activity for at least 480 min, with a negligible amount of coke deposition (1.0 %-C/h on average) and liquid effluent containing 55 − 150 ppm of organic carbon. The gasification efficiency of the depolymerized lignin achieved by Ru/C was superior to that of the raw lignin.
研究领域:
生物质能
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Xiaoli Jin,Chade Lv,Xin Zhou,Congmin Zhang,Qingqiang Meng,Yue Liu,Gang Chen
Oxide defect engineering in semiconductors is of growing interest and considered as an important strategy for promoting photocatalytic performance, as it enables to couple solar energy into oxygen activation. Herein, the surface oxygen vacancies are introduced into bismuth-rich Bi 4 O 5 I 2 nanosheets (Bi 4 O 5 I 2 -OV) via a facile solvothermal route. By introducing oxygen vacancies into Bi 4 O 5 I 2 , the molecule oxygen adsorption is significantly improved. More importantly, attributed to the molecular oxygen adsorption, an instantaneous surface-bulk homojunction is constructed, which facilitates the separation and transport of photogenerated charge carriers. Therefore, noticeable molecular oxygen activation and N 2 fixation are achieved in Bi 4 O 5 I 2 -OV. These findings may shed light on designing highly efficient photocatalysts and provide fresh insights into understanding the charge migration mechanism in oxygen vacancies-related photocatalytic system.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Zhijie Wang,Anxiang Guan,Mayfair C. Kung,Anyang Peng,Harold H. Kung,Ximeng Lv,Gengfeng Zheng,Linping Qian
Aerobic oxidation of α-C H bond of organic compounds to valuable chemicals is widely investigated in both fundamental research and industry. Due to the good stability of molecular oxygen, severe reaction conditions are generally required. Herein, by in situ synthesis we used molecular oxygen to induce cobalt nanoclusters with the sensitive catalysis in mild selective oxidation. The cobalt containing clusters with an average diameter around 0.9 nm are in situ prepared in the presence of cis -cyclooctene epoxidation and cyclooctene dimer oxide is formed at the interface to stabilize Co clusters with electron donation as an oil-soluble surfactant. The soluble clusters exhibit high activity in selective oxidation of α-C H bond of ethylbenzene into acetophenone and turnover number (TON) reaches about 7 × 10 4 during 50 h’ reaction at 373 K, which is around 960 times more active than the one using CoCl 2 salt as the catalyst, resulting from efficient mass transportation, π bond interaction and oxygen gas activation. Extended work based on this understanding demonstrates that cobalt nanoclusters also effectively catalyze aerobic oxidation of cyclohexene.
研究领域:
化学催化
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有机合成
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 46
·20358-20366
·
IF 3.288
Yan Gao,Ziyan Lv,Ruimin Gao,Guangfa Hu,Jianshe Zhao
Due to the increasingly severe environmental pollution, there is an urgent need to find a new catalyst with high efficiency and stability for deep desulfurization of fuels. In this work, hybrid material based on vanadium-substituted Dawson type polyoxometalate and poly ionic liquid was facilely prepared and successfully loaded on different carbon materials to produce a supported catalyst for oxidative desulfurization. The test result shows that the catalyst P[C2VP]MoV/AC possesses high activity with the DBT conversion of 99.2%. At the same time, the catalyst with large specific surface area has more opportunities to react with sulfides and thus possesses high activity. According to the kinetic study, it is confirmed that the oxidation reaction of DBT follows first-order kinetics.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 12
·34827-34839
·
IF 5.19
Zhang Xianfa,Shi Chang,Hu Hanjun,Zhou Zuoming,Zhao Xiaodan
Nano-zero-valent copper (nZVC) is a superior molecular oxygen (O 2 ) activator for the abatement of organic pollutants due to its high electron utilization rate. However, the activation efficiency of O 2 is compromised by the agglomeration tendency of nZVC particles and the concomitant reduction of the available active sites. To address this problem, the biochar (BC) with porous structure and abundant surface functional groups is utilized to disperse and stabilize nZVC for O 2 activation (simplified as the nZVC/BC/O 2 system) for efficient removal of tetracycline (TC). The nZVC/BC composite possesses a high specific area with well-distributed nZVC particles on the BC surface, which guarantees the superior dispersion and high reactivity in the activation of O 2 . The efficacy of the nZVC/BC/O 2 system for TC abatement is evaluated and the underlying mechanism is elucidated. The results show that nZVC/BC/O 2 system can achieve excellent removal of TC with the efficiencies of more than 85% in the pH range of 4.0–9.0, which originated from the combined action of complexation and degradation. The degradation is dominated by reactive oxygen species (ROS) including •OH, •O 2 − and 1 O 2 generated by Cu 0 /Cu + activated O 2 while the generation of Cu 2+ via oxygen oxidation on the surface of nZVC/BC can remove TC by complexation adsorption. This study highlights the complexation and degradation in the removal of TC and can be expected to exhibit application prospects in the water and wastewater treatment. Graphical Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2023
·
IF 12.9
Jielin Wang,Xin Li,Shujie Shen,Ruimin Chen,Qin Ren,Jieyuan Li,Fan Dong
Molecular oxygen (O2) activation has been utilized as a feasible approach to promoting the oxidative capacity of general environmental and energy catalytic reactions. However, the selectivity of oxidation reactions regulated by quantification of molecular O2 activation has not yet been clarified. By adjusting the concentration of dissolved oxygen (CDO), the quantified provision of molecular O2 can be facilely accomplished, which could directly regulate the production of reactive oxygen species (ROS) for targeted oxidative products. Herein, by taking ammonia oxidation as a typical multielectron-involved reaction, the selectivity is precisely tailored by quantified activation of molecular O2, in which P25 is utilized as the photocatalyst. Under the sufficient provision of molecular O2 activation (CDO = 20.0 mg L–1), the deep oxidation of NH3 into NOx– (NO2– and NO3–) is achieved via the ROS-driven mechanism. In contrast, selective production of N2 from partial NH3 oxidation is noted along with the h+-driven direct oxidation mechanism (CDO = 0.1 mg L–1). Then comprehensive in situ characterization under different CDO and theoretical calculations are combined, revealing that the regulation of product selectivity by quantified provision of the O2 can be attributed to the selective generation of ROS. It is proposed that the strategy of quantified activation of molecular O2 can be developed as an effective method, which offers opportunities for regulating the oxidation selectivity for important environmental and energy reactions.
研究领域:
环境科学
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催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Ming Ni,Minyuan Tan,Kang Luo,Daochuan Jiang,Yupeng Yuan,Chuhong Zhu,Haiwei Du,Hangjuan Ren
Water electrolysis has been considered as a green and sustainable technique for hydrogen production, while the sluggish kinetics of the oxygen evolution reaction (OER) and the insufficient active sites remain bottlenecks for practical performance. Herein, we present in situ electrochemical activation of nickel (Ni) alloys for water splitting assisted by the electro-oxidation of organic molecules. It has been discovered that in situ electrochemical activation results in an increased degree of metal oxidation, thereby inducing more high-valence active metal species (NiOOH). These species not only function as active sites for surface adsorption but also facilitate electron transfer. Subsequently, two representative organic molecules, methanol and ethanol, are introduced to further promote the water electrolysis. Through a combination of electrochemical testing and in situ Raman spectroscopy, it has been revealed that the activated Ni alloy demonstrates a stronger response to the adsorbed alcohol molecules and tends to form β-NiOOH at lower potentials compared to the pristine one, resulting in enhanced water splitting. The present work advances a simple activation method for transition metal-based electrocatalysts for highly efficient alcohol oxidation-assisted water electrolysis.
研究领域:
材料科学
·
电化学
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 16
·3896
·
IF 4.2
Min Tian,Haokang Huang,Gai Zhang,Haibo Wang
Novel and highly stable nitronyl nitroxide radical (NIT) derivatives were synthesized and coated on the surface of multi-walled carbon nanotubes (MWCNTs) to improve their desulfurization performance. They were characterized by FTIR, UV-vis, SEM, XRD, Raman spectroscopy and ESR. Thiophene in fuel was desulfurized by molecular O2, and the oxidation activity of these compounds was evaluated. At a normal temperature and pressure, the degradation rates of thiophene by four compounds in 4 h can reach 92.66%, 96.38%, 93.25% and 89.49%, respectively. The MWCNTs/NIT-F have a high special activity for the degradation of thiophene, and their desulfurization activity can be recycled for five times without a significant reduction. The mechanistic studies of MWCNTs/NIT composites show that the ammonium oxide ion is the key active intermediate in catalytic oxidative desulfurization, which provides a new choice for fuel oxidative desulfurization. The results show that NIT significantly improves the photocatalytic performance of MWCNTs.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2024
·
IF 10.8
Zhuoyan Lv,Yangming Ding,Leilei Kang,Lin Li,Xiao Yan Liu,Aiqin Wang,Tao Zhang
Direct epoxidation of propylene (DEP) by molecular oxygen is an ideal way to synthesize propylene oxide (PO), yet it remains quite challenging. We demonstrated here that the PO formation rate and selectivity could be enhanced simultaneously through photo-thermo-catalysis over the CuO x /TiO 2 catalyst. At 180 °C, by introducing light, the PO formation rate increased more than 20-fold (from 8.2 to 180.6 μmol g −1 h −1 ) and the corresponding selectivity improved more than 3-fold (from 8 % to 27 %), breaking the traditional perception that the semiconductors exhibit very low reactivity for this reaction. Kinetic study results showed that the apparent activation energy for PO formation could sharply decrease under light irradiation (from 95 to 40 kJ mol −1 ). In situ electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were applied to characterize the dynamics of the valence state of the copper oxide species and the activation intermediates of molecular oxygen. Evidence for the activation of oxygen, which could direct to the PO formation pathway, was captured. The light-driven electrons could promote the formation of active Cu + , which could form the side-on μ-peroxo Cu(II) 2 structure, weaken the O–O bond, and improve the PO formation rate and selectivity. This work paves a new way for designing semiconductor-supported photocatalysts for DEP reactions with molecular oxygen.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Weiyou Zhou,Qianyun Tao,Fu'an Sun,Xinbai Cao,Junfeng Qian,Jie Xu,Mingyang He,Qun Chen,Jianliang Xiao
NiMn layered hydroxide compounds have been found to be efficient catalysts for the oxidative dehydrogenation of N-heterocycles by molecular oxygen under mild conditions. Various tetrahydroquinoline derivatives and some other N-heterocycles have been found to be tolerated by the catalytic system. A synergistic effect between Ni and Mn has been observed in the reaction. A kinetic study concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and an apparent activation energy of 113 kJ/mol has been obtained. A probable reaction mechanism comprising an imine intermediate has been proposed according to the obtained results and XPS analysis. The key catalytic site for the dehydrogenation is thought to be Mn 3+ , which could be stabilized by Ni 2+ in the hydrotalcite structure.
研究领域:
催化化学
·
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Jinping Zhang,Shinichi Nagamatsu,Junmou Du,Chaoli Tong,Huihuang Fang,Dehui Deng,Xi Liu,Kiyotaka Asakura,Youzhu Yuan
Transition-metal nitrides can exhibit catalytic performance comparable to that of noble metal catalysts in many reactions. However, investigations on the correlation of catalyst structure, performance, and stability are still highly demanded. Here, a series of metal nitrides were prepared and evaluated for the selective oxidation of alcohols by molecular oxygen. Among them, FeN x /C- T catalysts ( T represents the pyrolysis temperature) display above 95% selectivity to the corresponding aldehydes in the selective oxidation of unsaturated alcohols. The optimized FeN x /C-900 catalyst gives the highest TOF of 7.0 h −1 for the conversion of 5-hydroxymethylfurfural to 2,5-diformylfuran. A combination of characterizations and experiments suggests that Fe N 4 species are the main active sites. In addition, we investigate the reasons for the catalyst deactivation and provide an effective approach to regenerating the catalysts. The results indicate that the deactivated catalysts can be regenerated by heat treatment under NH 3 /N 2 after each run. Based on these studies, a plausible reaction mechanism over the FeN x /C catalysts is proposed.
研究领域:
化学
·
材料科学
✓ 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）