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Surface-mediated iron on porous cobalt oxide with high energy state for efficient water oxidation electrocatalysis

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Green Energy & Environment 2022年第4期7卷 662-671页

作者： Jingsha Li Tao Hu Changhong Wang Chunxian Guo Institute of Materials Science and Devices Suzhou University of Science and TechnologySuzhou215011China

Surface engineering of active materials to generate desired energy state is critical to fabricate high-performance heterogeneous ***, its realization in a controllable level remains challenging. Using oxygen evolution reaction(OER) as a model reaction, we report a surface-mediated Fe deposition strategy to electronically tailor surface energy states of porous Co_(3)O_(4)(Fe-pCo_(3)O_(4)) for enhanced activity towards OER. The Fe-pCo_(3)O_(4) exhibits a low overpotential of 280 mV to reach an OER current density of 100 mA cm^(-2), and a fast-kinetic behavior with a low Tafel slop of 58.2 mV dec^(-1), outperforming Co_(3)O_(4)-based OER catalysts recently reported and also the noble IrO_(2). The engineered material retains 100% of its original activity after operating at an overpotential of 350 m V for 100 h. A combination of theoretical calculations and experimental results finds out that the surface doped Fe promotes a high energy state and desired coordination environment in the near surface region, which enables optimized OER intermediates binding and favorably changes the rate-determining step.

关键词： Surficial Fe doping cobalt oxides High energy state Water oxidation Oxygen evolution reactions

Robust cobalt oxide catalysts for controllable hydrogenation of carboxylic acids to alcohols

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Chinese Journal of Catalysis 2018年第2期39卷 250-257页

作者： Song Song Dong Wang Lu Di Chuanming Wang Weili Dai Guangjun Wu Naijia Guan Landong Li School of Materials Science and Engineering & National Institute for Advanced Materials Nankai University Tianjin 300350 China Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringNankai University Tianjin 300071 China SINOPEC Shanghai Research Institute of Petrochemical Technology Shanghai 201208 China

The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production,while efficient heterogeneous catalyst systems are still being ***,we report the selective hydrogenation of carboxylic acids using earth‐abundant cobalt oxides through a reaction‐controlled catalysis *** further reaction of the alcohols is completely hindered by the presence of carboxylic acids in the reaction *** partial reduction of cobalt oxides by hydrogen at designated temperatures can dramatically enhance the catalytic activity of pristine samples.A wide range of carboxylic acids with a variety of functional groups can be converted to the corresponding alcohols at a yield level applicable to large‐scale *** monoxide was established as the preferred active phase for the selective hydrogenation of carboxylic acids.

关键词： Selective hydrogenation Carboxylic acids Alcohols cobalt oxides Reaction‐controlled catalysis

Catalytic combustion of vinyl chloride emissions over Co_(3)O_(4) catalysts with different crystallite sizes

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Rare Metals 2021年第4期40卷 817-827页

作者： Wen-Chao Hua Ming-Qi Li Yang-Long Guo Guang-Tao Chai Hao Liu Yun Guo Li Wang Wang-Cheng Zhan Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of Co_(3) O_(4) catalysts was prepared by ammonia(Co-AP) and oxalate(Co-OP) precipitation,solgel(Co-SG),and urea hydrothermal(Co-UH) methods,and their physicochemical properties were characterised by numerous techniques including X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen sorption,X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction of H_(2)(H_(2)-TPR),temperature-programmed desorption of O_(2)(O_(2)-TPD),and temperature-programmed desorption of NH_(3)(NH_(3)-TPD).The catalytic activity of each catalyst was estimated for the catalytic combustion of vinyl chloride(VC) *** crystallite size of the Co_(3) O_(4) catalyst was found to be well correlated with the amounts of surface-adsorbed oxygen species and number of acid sites on the catalyst surface,and consequently,determined several physicochemical properties of the *** the catalysts studied here,the Co-AP catalyst exhibits the smallest crystallite size,which increases the specific surface area and the concentration of Co^(2+) on the catalyst ***,in turn,enhances the redox property,oxygen mobility,and the number of acid sites associated with the Co-AP *** fact,the Co-AP catalyst exhibits the best catalytic activity for VC combustion at 360℃and does not produce any chlorinated by-products.

关键词： Catalytic combustion Vinyl chloride cobalt oxides Crystallite size Preparation methods

Three-dimensional hierarchical Ca_(3)Co_(4)O_(9) hollow fiber network as high performance anode material for lithium-ion battery

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Science China(Technological Sciences) 2021年第3期64卷 673-679页

作者： GUAN ShouJie FAN QingLu LIU LiYing LUO JunCai ZHONG YiCheng ZHAO WeiMin HUANG ZhenCai SHI ZhiCong Smart Energy Research Centre School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006China Guangdong Engineering Technology Research Center for New Energy Materials and Devices Guangzhou 510006China College of Chemical Engineering and Safety Binzhou UniversityBinzhou 256503China Hangzhou LIAO Technology Co. Ltd.Hangzhou 310000China

Transition metal oxides have high specific capacity as anode materials for lithium-ion *** aggregation of particles and volume expansion during lithiation/delithiation restrict their *** this work,a three-dimensional hierarchical Ca_(3)Co_(4)O_(9)hollow fiber network assembled by nanosheets is prepared by an electrospinning combined with heat treatment method to overcome these issues and to boost its lithium storage ***-synthesized sample possesses excellent cyclic stability(578.6 m A h g^(-1)at 200 m A g^(-1)after 500 cycles)and rate performance(293.5 m A h g^(-1)at 5000 m A g^(-1)),much better than those of commercial Co_(3)***,the fast kinetics of the three-dimensional Ca_(3)Co_(4)O_(9)hollow fiber network is also confirmed by the variable scan rates CV tests and the EIS measurements,which is dedicated to the specific hierarchical hollow fiber network structure that provides shorter ion transport distances and higher electrical *** work supplies a universal approach to improve the electrochemical performance of transition metal oxides for lithium ion batteries.

关键词： lithium ion battery anode material cobalt oxides electrospinning hierarchical structure

Preparation and electrochemical properties of Co_3O_4/graphite composites as anodes of lithium ion batteries

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Journal of Central South University 2010年第3期17卷 498-503页

作者：郭华军李向群李新海王志兴彭文杰孙乾明谢杰 School of Metallurgical Science and Engineering Central South University

Co3O4/graphite composites were synthesized by precipitation of cobalt oxalate on the surface of graphite and pyrolysis of the precipitate, and the effects of graphite content and calcination temperature on the electrochemical properties of the composites were investigated. The samples were characterized by thermogravimetry and differential thermal analysis （TG/DTA）, X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and charge/discharge measurements. With increasing the graphite content, the reversible capacity of the Co3O4/graphite composites decreases, while cycling stability improves dramatically, and the addition of graphite obviously decreases the average potential of lithium intercalation/deintercalation. The reversible capacity of the composites with 50% graphite rises from 583 to 725 mA-h/g as the calcination temperature increases from 300 to 500 ℃, and the Co304/graphite composites synthesized at 400 ℃ show the best cycling stability without capacity loss in the initial 20 cycles. peaks, corresponding to the lithium intercalaction/deintercalation for The CV profile of the composite presents two couples of redox graphite and Co3O4, respectively. EIS studies indicate that the electrochemical impedance decreases with increasing the graphite content.

关键词： composite materials cobalt oxides lithium ion batteries graphite electrochemical properties precipitation

Chemoselective hydrogenation of phenol to cyclohexanol using heterogenized cobalt oxide catalysts

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Chinese Chemical Letters 2018年第6期29卷 815-818页

作者： Zhongzhe Wei Yi Li Jing Wang Haoran Li Yong Wang Institute of Industrial Catalysis College of Chemical Engineering State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology ZhejiangUniversity of TechnologyHangzhou 310014 China Advanced Materials and Catalysis Group ZJU-NHU United R&D Center Department of Chemistry Zhejiang University Hangzhou 310028 China

Cyclohexanol is an important intermediate in the synthesis of Nylon-6 and plasticizers. In this work,cobalt oxide nanoparticles（NPs） supported on porous carbon（Co Ox@CN） were fabricated by one-pot method and the hybrids could efficiently and selectively hydrogenate phenol to cyclohexanol with a high yield of 98%. The high catalytic performance of Co Ox@CN was associate with the high surface area（340 m2/g） and uniformly dispersed NPs. Furthurmore, by detailed analysing the relationship between catalytic activity and catalysts composition, it clearly indicated that the Co3O4 in Co Ox@CN played an important role for the adsorption and activation of phenol and the in situ gernerated Co was responsible for hydrogen adsorption and dissociation. These findings provide a fundamental insight into the real active sites in hydrogenation of phenol using Co-based catalysts.

关键词： Phenol Cyclohexanol Selective hydrogenation cobalt oxides Metallic cobalt

cobalt valence modulating in CoO_(x) incorporated carbon nanofiber for enhanced glucose electrooxidation

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Materials Reports(Energy) 2022年第2期2卷 86-93页

作者： Jiadong Hu Hao Lu Mingsong Li Gang Xiao Min Li Xuemei Xiang Zhisong Lu Yan Qiao Institute for Clean Energy&Advanced Materials School of Materials&EnergySouthwest UniversityChongqing400715PR China

Glucose fuel cells(GFCs)driven by abiotic catalysts are promising green power sources for portable or wearable *** 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 *** cobalt valence modulating could be achieved via regulating the incorporation ratio of cobalt acetate in precursors or the oxidation temperature of the pyrolyzed *** 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 *** a result,the glucose fuel cell built with the CoO.@CNF anode containing both CoO and Co_(3)O_(4)delivered a maximum power density of 270μW cm^(-2),which is higher than that of other reported Co_(3)O_(4)based *** work provides a simple strategy to develop excellent transition metal catalysts for GFCs to expand their applications in portable and wearable energy devices.

关键词： Glucose electrooxidation cobalt oxides Valence modulating Carbon nanofiber Wearable glucose fuel cell

Mn_(x)Co_(3-x)O_(4)Microtubules with Enhanced Catalytic Activity Towards Toluene Combustion:Effects of Redox Property and Oxygen Species

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China Petroleum Processing & Petrochemical Technology 2021年第4期23卷 7-17页

作者： Zhang Hanyu Hu Yue Zhang Xiaohan Sun Mengyao Liu Rui Qi Jian Jin Quan Key Laboratory of Automobile Materials(Ministry of Education) School of Materials Science and EngineeringJilin UniversityChangchun 130022 School of Chemical Engineering Dalian University of TechnologyPanjin 124221 College of Environmental and Safety Engineering Shenyang University of Chemical TechnologyShenyang 110142 State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190

The redox property and oxygen species play an important role in the catalytic oxidation of volatile organic compounds(VOCs).In this paper,a series of Mn_(x)Co_(3-x)O_(4)catalysts with tubular structure were synthesized and applied for the catalytic combustion of *** characterization technologies were employed to reveal the relationship between the catalytic performance of the Mn_(x)Co_(3-x)O_(4)catalysts and Mn *** results of XRD,SEM and N2 adsorption-desorption analyses showed that the Mn doping had significant effects on the structure and morphology of the Mn_(x)Co_(3-x)O_(4)*** H2-TPR,O2-TPD,and XPS results proved that the strong interaction between Co and Mn resulted in the enhanced Olatt mobility,the richer active oxygen species,and the enhanced redox property in comparison with the pure Co_(3)O_(4)sample,which were crucial to the improvement of the catalytic activity of Co-Mn *** best catalyst,Co5-Mn5 sample,exhibited a good and stable activity to catalytically oxidize toluene at low temperatures even in the presence of water vapor,indicating that it is a potential material to be used in the commercialization of catalytic abatement of toluene.

关键词： catalytic combustion cobalt oxides manganese doping,toluene

Graphene-supported ultra-small Co_3O_4 nanoparticles for high-performance supercapacitors

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储能科学与技术 2016年第6期5卷 841-848页

作者： LIU Zheng LI Ji WU Xiaoliang WEI Tong FAN Zhuangjun Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Material Scence and Chemical EngineeringHarbin Engineering University

Ultra-small Co_3O_4 nanoparticles/graphene hybrid material had been synthesized by a facile hydrothermal route and consequent calcination *** as-obtained ultra-small Co_3O_4 nanoparticles with their sizes of 5–8 nm are tightly anchored on the surface of graphene(GNS).Benefiting from the ultra-small size of Co_3O_4 nanoparticles,the high interconnectivity of hybrid material as well as the high conductive networks constructed by GNS,which can provide a fast and efficient transportation of electron and electrolyte ions for the overall electrode,the as-prepared hybrid material exhibits a high specific capacitance of 462 F·g^(-1) at 5 m V·s^(-1) compared with pure Co_3O_4(193 F·g^(-1)),and retained 88.2% of its initial capacitance after 2000 cycles,indicating a promising electrode material for supercapacitors.

关键词： ultra-small nanoparticles cobalt oxides graphene supercapacitors