APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Bin Yao,Jianqi Ye,Chen Wang,Wenjing Mu,Fei Liu,Dan Wen
Noble metal aerogels with unique porous structure have demonstrated tremendous potentials in electrocatalysis due to its excellent electrical conductivity, large specific surface area, high porosity, and prominent activity. However, the traditional two-step synthetic method is time-consuming and complicated, limiting its development and application. In this work, we synthesized Pd-CoO x aerogels simply and quickly by in situ electrochemical reduction strategy without additional organic ligands. Interestingly, introducing Co to form composite aerogels significantly improved the catalytic performance of Pd due to the synergy between Pd and Co. The optimized Pd 3 -(CoO x ) 1 aerogel exhibited excellent electrocatalytic activities in alcohol oxidations after the in situ electrochemical activation. Specifically, the mass activities of the Pd 3 -(CoO x ) 1 aerogel for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) reached 4.94 A mg Pd −1 and 8.67 A mg Pd −1 , respectively, which are 10.5 times and 7.4 times higher than those of the commercial Pd/C. These findings may offer a facile synthetic strategy for composite aerogel catalysts with high electrocatalytic performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 38
·20195-20201
·
IF 8.867
Jiuwang Gu,Qitong Huang,Yufei Yuan,Kai-Hang Ye,Zilong Wang,Wenjie Mai
Unfavorable interfacial electron back-injection, sluggish surface kinetics, and poor bulk conductivity leading to remarkable recombination are the key issues which significantly hinder the solar-to-hydrogen efficiency of PEC photoanodes. In this study, Ti foil is employed as the substrate for fabricating BiVO4 photoanodes. Surface passivation of TiO2 is sophisticatedly designed to block interface recombination in solar water splitting for the first time, so that a significant two-fold increase in photocurrent and a large decrease in dark current are observed. In addition, to address the other two issues, CoOx oxygen evolution catalysts (OECs) and Mo/N doping are applied to increase the photocurrent density and applied bias photon-to-current efficiency to 5.04 mA cm−2 at 1.23 VRHE and 1.41% at 0.75 VRHE, respectively, under AM 1.5 G illumination, which suggests the great potential of integrating strategies to target specific issues in BiVO4 photoanodes.
研究领域:
材料科学
·
能源科学
·
光电化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 21
·8633-8644
·
IF 9.8
Anqiu Liu,Xixi Liu,Yaping She,Xiaoqiang Hu,Miao Hu,Zehui Zhang,Xiaochen Wang,Bing Liu
Selective hydrodeoxygenation transformations constitute the most pivotal industrial processes in chemistry and catalysis. Herein, we have rationally designed a heterogeneous Co/CoOx catalytic system with metallic Co and oxygen vacancies in CoOx for selective hydrodeoxygenation of structurally diverse ketones and nitro compounds under mild conditions (80–100 °C and 10 bar H2), which shows a superior performance compared to state-of-the-art noble-metal catalysts. Experimental results and DFT calculation revealed that oxygen vacancies not only promote the adsorption and activation of substrates and the intermediates via electronic interactions, but also enable the hydrodeoxygenation reactions in a low-energy pathway via the direct hydrogenolysis process, instead of the dehydration–hydrogenation process. Given its generality and efficiency, it is believed that this method can serve as a practical, economically viable approach for selective hydrodeoxygenation reactions, which should impact both the chemical industry and scientific research.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Liao Yijun,Yulan Zhou,Side Fu,Huang Jiaxun,Wu Leyi,Xuejun Xu,Manfang Mai,Xinzhou Ma
BiVO 4 is one of the most promising photoanodes for photoelectrochemical water splitting but their performance is still limited by charge recombination and sluggish surface kinetics. To deal with these limitations, various Co:BiVO 4 /CoO x photoanodes were prepared in this work. Photocurrent density was increased by a factor of 2-3 by optimizing Co-doping. To find out the enhance mechanism, photoinduced absorption spectroscopy (PIAS) was employed to establish the relationship between photocurrent density and concentration of the photogenerated holes on surface. Meanwhile, intensity-modulated photocurrent spectroscopy (IMPS) was applied to measure the rate constant of charge transfer and surface recombination. The improved PEC performance was attributed to the synergy effect of Co-doping that increased the bulk charge separation efficiency and significantly suppressed surface recombination by two orders of magnitude at high potentials. More importantly, our investigation reveals that not all the surface holes could participate in water oxidation reaction and the utilization proportion of them was strongly dependent on Co-doping and potential. Not more than 12 % of the photogenerated holes were used for water oxidation on the pristine BiVO 4 surface over a wide potential range. In contrast, as high as 80 % of the photogenerated holes participated in water oxidation with the assistance of the CoO x nano-catalysts. It is the critical enhancement mechanism of the Co:BiVO 4 /CoO x photoanodes for photoelectrochemical water oxidation.
研究领域:
材料科学
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能源科学
·
光催化
✓ 已验证
DOI
高影响因子
Materials Reports: Energy
·
2022
·
IF 0
Jiadong Hu,Hao Lu,Mingsong Li,Gang Xiao,Min Li,Xuemei Xiang,Zhisong Lu,Yan Qiao
Glucose fuel cells (GFCs) driven by abiotic catalysts are promising green power sources for portable or wearable devices . In this work, a CoO x incorporated carbon nanofiber (CoO x @CNF) catalyst with mixed valences cobalt oxides have been developed through partial oxidation of pyrolyzed electrospun Co 2+ /poly acrylonitrile fibers. The cobalt valence modulating could be achieved via regulating the incorporation ratio of cobalt acetate in precursors or the oxidation temperature of the pyrolyzed fibers. Electrocatalytic analyses show that the presence of CoO in CoO x @CNF will provide more active sites for glucose electrooxidation, and thus enhance the electrocatalytic performance significantly. As a result, the glucose fuel cell built with the CoO x @CNF anode containing both CoO and Co 3 O 4 delivered a maximum power density of 270 μW cm −2 , which is higher than that of other reported Co 3 O 4 based GFCs. This work provides a simple strategy to develop excellent transition metal catalysts for GFCs to expand their applications in portable and wearable energy devices.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
DOI
CATALYSIS COMMUNICATIONS
·
2015
·
IF 3.699
X.-T. Ma,X.-H. Lu,C.-C. Wei,Z.-S. Zhao,H.-J. Zhan,D. Zhou,Q.-H. Xia
The supported CoO x /zeolites have been prepared and applied for the epoxidation of cyclic alkenes with air. The catalysts are characterized by powder X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–vis) and scanning electron microscope (SEM). Among these CoO x /zeolite catalysts, 2.4% CoO x /Y exhibits the best catalytic activity for the epoxidation of cis -cyclooctene with 61.2 mol% conversion and 98.8 mol% selectivity of epoxide. Some factors such as the kind of zeolites, the oxidants, the solvents, the Co contents, the reaction temperature and time play important roles in controlling the epoxidation. The recyclable stability of the 2.4% CoO x /Y catalyst is confirmed.
研究领域:
催化化学
·
材料科学
·
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Fang Sun,Guoxin Zhang,Yuqi Xu,Zheng Chang,Pengbo Wan,Yaping Li,Xiaoming Sun
CoO x incorporated in Ag/reduced graphene oxide nanocomposites (CoO x -Ag/rGO) were synthesized through an one-pot solvothermal method. Electrochemical results showed that CoO x nanoparticles could greatly promote dispersion of anchored Ag nanoparticles and increase the limiting current density for the whole CoO x -Ag/rGO nanocomposites when catalyzing oxygen reduction reaction (ORR) in alkaline medium. With CoO x formation beside the Ag nanoparticles, a much higher current density and a preferable four-electron pathway were achieved for the CoO x -Ag/rGO nanocomposites. Meanwhile, the CoO x -Ag/rGO nanocomposites showed remarkable long-term stability and tolerance toward methanol than the commercially available 20% Pt/C catalyst. More importantly, this work could finally lead to a practical significance for developing high-performance bicomponent electrocatalysts with low-cost for fuel cells and relevant electrochemical technologies.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Technology & Innovation
·
2023
·
IF 7.1
Pengyu Zhu,Haolin Li,Xiuyun Sun,Jiansheng Li,Jinyou Shen,Weiqing Han,Wei Zhang
Bisphenol A (BPA) is an emerging organic pollutant that can disturb endocrine systems at trace levels in water. This study constructed a photocatalyst of cobalt oxide modified bismuth vanadate (CoO x /BiVO 4 ) coupled with peroxymonosulfate (PMS) oxidation system to investigate its photocatalytic mechanism for degrading BPA in wastewater. The CoO x /BiVO 4 photocatalyst was fabricated through a precipitation-hydrothermal method and systematically characterized. The results showed that modifying BiVO 4 with CoO x significantly improved the separation and migration efficiency of photogenerated electron–hole pairs, thereby enhancing the photocatalytic activity of the system. Through active species trapping experiments using different scavengers, singlet oxygen ( 1 O 2 ) and sulfate radicals (SO 4 − ⋅ ) were identified as the predominant reactive oxygen species responsible for BPA degradation. BPA photocatalytic reaction intermediates were analyzed using HPLC-MS, which proposed three possible degradation pathways: (1) Initial hydroxylation of BPA by SO 4 − ⋅ and ⋅ OH radicals; (2) Ring-opening oxidation of hydroxylated intermediates into carboxylic acids; (3) Further mineralization of all intermediates into CO 2 and H 2 O by 1 O 2 and ⋅ OH. In summary, the CoO x /BiVO 4 -PMS system provides an efficient and promising technology for eliminating trace BPA in wastewater via synergistic effects of SO 4 − ⋅ and 1 O 2 . Further optimization of CoO x loading and PMS dosage is still needed to maximize the overall photocatalytic performance.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Deyu Qin,Chen Zhang,Fanzhi Qin,Yin Zhou,Danlian Huang,Hou Wang,Hanzhuo Luo,Qi Wang,Lin Tang,Wenwei Li
Developing atomically dispersed metal sites is vital to enhance the activation of peroxymonosulfate (PMS). However, for catalyst systems where single atoms and nanoclusters coexist, how to identify the independent and synergistic effects of atomic sites and investigate the possible coexistence of multiple activation mechanisms still remains a great challenge. Herein, Cu SA /CoO x -CeO 2 catalysts with Cu single atoms and CoO x nanoclusters were fabricated for PMS activation. The introduction of Cu single atoms led to the reconstruction and diversification of catalytic active sites of CoO x -CeO 2 . The synergy between CoO x nanoclusters and neighboring Cu single atoms in Cu SA /CoO x -CeO 2 catalyst led to the 1 O 2 pathway of PMS activation, while the isolated Cu atom induced the Cu(III) oxidation pathway. The introducing of adjacent Cu single atoms caused the redistribution of the site charges in CoO x nanoclusters, which enhanced the charge transfer and promoted the adsorption and activation behavior of PMS molecules. During the evolution of 1 O 2 , the synergistic effect of Cu single atoms and CoO x nanoclusters increased the stability of the reaction intermediate state (*OO*SO 3 ), reducing the total Gibbs free energy change (ΔG) required for 1 O 2 formation. Compared with the cooperative site, the isolated Cu-O4 sites exhibited stronger charge transfer capacity to PMS molecules and were more conducive to the activation of the local substrate electronic structure, facilitating the formation and stabilization of Cu(III)–OH metastable intermediates. Overall, this study demonstrated the importance about the construction of multi-site induced multipath coexisting PMS activation system and the accurate identification of active sites.
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
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Zhimin Ma,Sujuan Li
In this work, visible light driven enzyme-free glucose PEC sensor was developed by electrochemically deposited CoO x nanosheets on graphene-CdS nanocomposites modified electrode to achieve both the electrocatalytic and photoelectrocatalytic oxidation of glucose at the resultant CoO x /graphene-CdS nanocomposites modified electrode. Scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the morphology and electrochemical properties of the resultant CoO x /graphene-CdS nanocomposites. The CV results demonstrated that decoration of CoO x nanosheets largely enhanced the photoelectrocatalytic activity of graphene-CdS composites toward glucose oxidation in alkaline solution. The glucose detection sensitivity under visible light irradiation is dramatically improved compared to dark condition. Good performance was obtained for the CoO x /graphene-CdS nanocomposites based glucose sensor. The feasibility of the present method was confirmed by good recovery results for glucose detection in human urine samples.
研究领域:
生物传感
·
纳米材料
·
电化学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 7
·2131-2140
·
IF 3.186
Zhu Kehui,An Yunlei,Yu Fei,Liu Li,Zhong Liangshu
The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated in detail. It was found that the catalytic activity sharply decreased in the first 30 h with the ethylene conversion decreasing from 64 to 4%. Butene selectivity increased gradually in the first 10 h then remained about 74%, while the selectivity for hexene and octene exhibited an opposite trend. The ratio of α-olefin to isomers for butene increased greatly with time on stream and most of the generated butene was 1-butene. Based on the structure characterization at different reaction stages, CoO x was suggested to be major active phase and the coverage of long-chain hydrocarbons as well as the loss of surface CoO x active sites due to size growth of Co 3 O 4 nanoparticles were the main reasons for catalytic deactivation. Graphic Abstract The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated and the coverage of long-chain hydrocarbons as well as the loss of surface CoO x active sites due to size growth of Co 3 O 4 nanoparticles were the main reasons for catalytic deactivation
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 13
·1132
·
IF 4.4
Yanliang Zhai,Lisha Chen,Ruihan Wu,Xianggang Lu,Jun Wang,Gaolong Li,Bicheng Tang,Wei Zhang,Shaolong Zhang,Zhijun Li
Co-based catalysts have shown great promise for propane dehydrogenation (PDH) reactions due to their merits of environmental friendliness and low cost. In this study, ordered mesoporous molecular sieve-supported CoOxspecies (CoOx/Al-SBA-15 catalyst) were prepared by one-step organometallic complexation. The catalysts show worm-like morphology with regular straight-through mesoporous pores and high external specific surface area. These typical features can substantially enhance the dispersion of CoOxspecies and mass transfer of reactants and products. Compared with the conventional impregnation method, the 10CSOC (10 wt.% Co/Al-SBA-15 prepared by the organometallic complexation method) sample presents a smaller CoOxsize and higher Co2+/Co3+ratio. When applied to PDH reaction, the 10CSOC delivers higher propane conversion and propylene selectivity. Under the optimal conditions (625 °C and 4500 h−1), 10CSOC achieves high propane conversion (43%) and propylene selectivity (83%). This is attributed to the smaller and better dispersion of CoOxnanoparticles, more suitable acid properties, and higher content of Co2+species. This work paves the way for the rational design of high-performance catalysts for industrially important reactions.
研究领域:
催化化学
·
材料科学
✓ 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）