JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Haiqiang Bai,Biao Liu,Ling Kang,Yanhong Wang,Jing Bai,Santosh Kumar Verma,Yunhua Xu
The ability of magnesium-based hydrogen storage materials to store and release hydrogen is hampered by their relatively slow rates. To address this, Mg-x% Co (x = 5, 10, 15) magnesium-rich hydrogen storage alloys were fabricated using reactive ball milling. The resulting alloys were multiphase, composed of Mg, Co, MgCo₂, and Mg₂CoH₅, which provided nucleation sites and improved hydrogen uptake. The reduced particle size and surface microcracks and pores enhanced hydrogen diffusion. The Mg-15 %Co alloy had the ability to take in 4.72 wt% hydrogen in 1 min when the temperature was set at 350°C. Hydrogenation resulted in the formation of a biphasic structure composed of Mg₂CoH₅ and Mg₆Co₂H₁₁. This structure destabilized the Mg-H bond and improved the kinetics of hydrogen release. The hydrogen release capacity first increased and then decreased with Co content, with Mg-10 %Co showing the best performance. Due to the combined action of ball milling and Co catalysis, the Mg-10 %Co alloy had an activation energy for hydrogen release of 113.65 kJ/mol, making it the alloy with the lowest such activation energy in the set. Differential scanning calorimetry (DSC) analysis confirms that cobalt addition reduces the hydrogen release peak temperature of Mg by 16.58–29.67 °C, with the Mg-10 % Co alloy exhibiting peak temperatures of 410.72–425.53 °C, attributed to synergistic decomposition of MgH₂ with intermediate hydrides like Mg₂CoH₅ and Mg₆Co₂H₁₁. The findings of this study indicate that alloying Mg-based alloys with transition elements while performing ball milling is a practical method for enhancing their hydrogen storage and release kinetics.
研究领域:
材料科学
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能源存储
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纳米技术
·
合金工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2015
·
IF 12.113
Haiyan Jin,Jing Wang,Diefeng Su,Zhongzhe Wei,Zhenfeng Pang,Yong Wang
Remarkable hydrogen evolution reaction (HER) or superior oxygen evolution reaction (OER) catalyst has been applied in water splitting, however, utilizing a bifunctional catalyst for simultaneously generating H2 and O2 is still a challenging issue, which is crucial for improving the overall efficiency of water electrolysis. Herein, inspired by the superiority of carbon conductivity, the propitious H atom binding energy of metallic cobalt, and better OER activity of cobalt oxide, we synthesized cobalt–cobalt oxide/N-doped carbon hybrids (CoOx@CN) composed of Co0, CoO, Co3O4 applied to HER and OER by simple one-pot thermal treatment method. CoOx@CN exhibited a small onset potential of 85 mV, low charge-transfer resistance (41 Ω), and considerable stability for HER. Electrocatalytic experiments further indicated the better performance of CoOx@CN for HER can be attributed to the high conductivity of carbon, the synergistic effect of metallic cobalt and cobalt oxide, the stability of carbon-encapsulated Co nanoparticles, and the introduction of electron-rich nitrogen. In addition, when used as catalysts of OER, the CoOx@CN hybrids required 0.26 V overpotential for a current density of 10 mA cm–2, which is comparable even superior to many other non-noble metal catalysts. More importantly, an alkaline electrolyzer that approached ∼20 mA cm–2 at a voltage of 1.55 V was fabricated by applying CoOx@CN as cathode and anode electrocatalyst, which opened new possibilities for exploring overall water splitting catalysts.
研究领域:
材料科学
·
电化学
·
能源转换与存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Haoran Song,Longyu Chen,Yi hang Xu,Chen Li,Xuewei Hu,Yingjie Li,Shugen Liu,Jianhong Huang,Qun Zhao,Jie Li,Senlin Tian
Activation of peroxymonosulfate (PMS) by MXene-supported Co 3 Ti and single-atom Co catalyst (Co@MXene) achieved the efficient decomplexation of lead-ethylenediaminetetraacetic acid (Pb-EDTA) and the recovery of lead (Pb) over the pH range of 3.0–9.0. The removal efficiency of Pb-EDTA reached up to 93.6 % within 30 min and total Pb was completely removed within 15 min. The coordination structure differences between Co 3 Ti and single-atom Co induced their various electron transfer pathways with PMS, in which Co 3 Ti brought key effect to the generation of Co (Ⅳ), while single-atom Co and regenerative Co (II) were responsible for the generation of HO and SO 4 − and 1 O 2 , More importantly, the oxygen transfer reaction from O-Co 3 Ti to Co 3 Ti-O and the reducibility of MXene triggered the regeneration of low-valent Co. This study proposed a novel mechanism of Co (Ⅳ) generation and low-valent Co regeneration, which improved the understanding of the electron transfer pathways of Co@MXene/PMS oxidation process.
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
Nanomaterials
·
2022
·Vol. 12
·期 19
·3388
·
IF 5.719
Qichang Guo,Jingbo Mao,Shenmin Li,Jingmei Yin,Yang Lv,Jinxia Zhou
Herein, cobalt-reduced graphene oxide (rGO) catalyst was synthesized with a practical impregnation–calcination approach for the selective hydrodeoxygenation (HDO) of guaiacol to cyclohexanol. The synthesized Co/rGO was characterized by transmission electron microscopy (TEM), high-angle annular dark-field scanning TEM (HAADF-STEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD), and H2temperature-programmed reduction (H2-TPR) analysis. According to the comprehensive characterization results, the catalyst contains single Co atoms in the graphene matrix and Co oxide nanoparticles (CoOx) on the graphene surface. The isolated Co atoms embedded in the rGO matrix form stable metal carbides (CoCx), which constitute catalytically active sites for hydrogenation. The rGO material with proper amounts of N heteroatoms and lattice defects becomes a suitable graphene material for fabricating the catalyst. The Co/rGO catalyst without prereduction treatment leads to the complete conversion of guaiacol with 93.2% selectivity to cyclohexanol under mild conditions. The remarkable HDO capability of the Co/rGO catalyst is attributed to the unique metal–acid synergy between the CoCxsites and the acid sites of the CoOxnanoparticles. The CoCxsites provide H while the acid sites of CoOxnanoparticles bind the C-O group of reactants to the surface, allowing easier C-O scission. The reaction pathways were characterized based on the observed reaction–product distributions. The effects of the process parameters on catalyst preparation and the HDO reaction, as well as the reusability of the catalyst, were systematically investigated.Keywords:cobalt–graphene catalyst;Co single atoms;Co oxide nanoparticles;hydrodeoxygenation;guaiacol;cyclohexanol
研究领域:
催化
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Chunhao Wang,Xiang Xu,Yang Guo,Fan Zhou,Hongyu Chen,Haoyang Li,Zheng Zeng,Liqing Li
The cobalt carbide (Co2C) innovatively prepared from Co–Mn layered double hydroxide (CoMn LDH) has been investigated and evaluated toward its alternative synthesis conditions and different catalytic performances. Along with various characterization techniques, the preparation basically contains four steps (synthesis of CoMn LDH, calcination, reduction, and crystallization) that transform CoMn LDH to CoMn spinel and then to Co2C. Catalyst evaluation toward toluene pyrolysis was conducted. The sample with Co2C exhibited almost 100% conversion rate of toluene, where the resulting hydrogen yield (∼1.8%) is 6 times more than that of the blank test by using silica sand (∼0.3%), realizing the full transfer of hydrogen element from toluene to hydrogen molecule. Furthermore, based on the textural analysis and density functional dispersion correction calculation, which theoretically explained the easy accessibility of toluene to the crystal surface of Co2C(001) with a relatively high adsorption energy (about −280 kJ mol–1), it suggested that Co2C may expand more extensive applications in the field of catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jiaming Wang,Guilong Liu,Huixian Zhong,Pengfei Song,Kang An,Ziyang Zhang,Ang Cao,Yuan Liu
In this work, Co δ+ -Co 2 C decorated-Co-Ni alloy nanoparticles (NPs) loaded on Mg-Al-O complex oxides were fabricated via an in-situ reduction and topochemical carbonization strategy by using hydrotalcite as the precursor. The Co δ+ -Co 2 C decorated-Co-Ni alloys were obtained via the following process: (I) after reduction, Co-Ni alloy was obtained and Co could donate electrons to Ni in the Co-Ni alloy NPs; (II) in syngas atmosphere, some of cobalt atoms on the surface of Co-Ni NPs reacted with CO and were converted to Co 2 C. Resultantly, in the reaction process, Co-Ni alloy NPs were transformed into Ni-Co alloy@Co-Co 2 C, a core-shell structure with Ni-Co alloy core and Co-Co 2 C shell. When used as the catalysts for direct ethanol synthesis (DES) from syngas, the bimetallic Co-Ni alloy@Co-Co 2 C catalyst performed excellent selectivity to ethanol, owing to the regulation of dissociatively and associatively adsorbed CO by Co δ+ -Co 2 C active sites formed on the surface of Co-Ni alloy NPs. Moreover, the mutual dilution between Co and Ni in the Co-Ni alloy NPs inhibited the generation of heavy hydrocarbons, further improving the selectivity to alcohols. The total alcohol selectivity of 43.0% and ethanol occupied 45.2 wt% could be reached over the optimal catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2022
·Vol. 7
·期 2
·389-397
·
IF 6.813
Junwei Li,Yige Wang,Wenwei Liu,Zhenyi Liang,Chunlei Fan,Jinying Li,Shengxu Luo,Haoxiong Nan,Jia Yu
With the aggravation of the environmental pollution problem and the depletion of natural resources, hydrogen production based on water splitting technology has become an effective method to satisfy the increasing demand for renewable energy. It is vital to design high-efficiency and low-cost electrocatalysts for water splitting. Herein, an electrocatalyst (Co3O4–S/NF) with a surface-sulphurated nanowire array structure is controllably synthesized for catalysing the oxygen evolution reaction (OER) process. Co3O4–S/NF (1 : 0.5) exhibits the best OER activity with an overpotential of 297 mV at 100 mV cm−2, which is lower than the overpotential (331 mV) of commercial Ir/C/NF. Additionally, the water-splitting voltage of the Co3O4–S/NF//Pt/C/NF electrolyzer reaches 1.571 V at 20 mV cm−2, which is also better than that of conventional noble-metal electrocatalysts. Notably, Co3O4–S/NF//Pt/C/NF also shows excellent efficiency in seawater electrolysis. The voltage reaches 1.656 V in a simulated alkaline seawater electrolyte (1 M KOH + 0.5 M NaCl) and 1.722 V in an alkaline seawater electrolyte (1 M KOH in seawater). This work can provide a robust electrocatalyst design for water electrolysis.
研究领域:
材料科学
·
可再生能源
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jiaqi Chen,Lili Zhang,Jingwen Sun,Junwu Zhu,Xin Wang,Yongsheng Fu
Ingenious design of catalysts structure is vital for accelerating ammonium perchlorate (AP) thermal decomposition at lower temperature and accompanying with more heat release. In this work, a self-templated approach is adopted to construct hierarchical hollow double-shelled Co 3 O 4 using cobalt glycerate solid spheres as precursors. The structural transformation from the solid species to the hollow double-shelled Co 3 O 4 sphere is implemented by a solution growth combined with a subsequent calcination . The hierarchical hollow double-shelled morphology, large surface area and unique electronic structure endue Co 3 O 4 with enhanced catalytic performance for thermal decomposition of AP. The AP decomposition temperature is decreased to 318 °C and heat release is increased from 491 J g −1 to 1280 J g −1 .
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Lingyu Liu,Zihua Wang,Xue Zhong Wang
A modified sol-gel method employing alginic acid (H-ALG) granule as gelation media was developed for the synthesis of cobalt oxides in this investigation. High-temperature decomposition mechanism of alginic acid was studied using simultaneous thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry (MS). The main emissions were water, carbon dioxide and carbon monoxide with − 7444.8 J/g heat flow measured at temperatures between 200 and 500 °C. In contrast, the energy released using the cobalt alginate (Co-ALG) sample was determined as − 8296.2 J/g at this temperature range. The oxidation states of the Co-ALG sample gradually changed, resulting in a conversion from Co 3 O 4 to CoO at high temperatures. According to the powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis, single phase cubic Co 3 O 4 were produced with particle size ~25 nm after calcination at 500 °C for 2 h. The ability of H-ALG to attract metal ions, such as Co, could be considered as a low cost and simple route for a large scale production of high purity metal oxides at significantly low temperatures due to the tremendous amount of energy released during the combustion reaction of the alginate structure.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Keke Yang,Guilin Song,Yuanyuan Li,Qingda An,Shangru Zhai,Zuoyi Xiao
Nowadays there is much room for improvement in the designed synthesis of high-performance electromagnetic wave absorbers by combining metal-organic frameworks (MOFs) and biomass components. Herein, 3D N-doped porous carbon cobalt/cobalt oxide (NPC/Co/CoO) composites were successfully prepared by transforming in-situ grown ZIF-67 clusters on a chitosan matrix. Analysis results showed that the N-doped carbonaceous composites obtained had unique porosity, high specific surface area, and defect-enriched structure, which provided numerous paths for electron transfer , leading to big benefits to interfacial polarization and dipole polarization. Most importantly, the ferromagnetic resonance and magnetic coupling were enhanced by ZIF-67-derived Co/CoO nanoparticles . By adjusting the content of metallic cobalt salt, pyrolysis temperature, and sample filling content, the optimal impedance matching properties of the composites could be optimized. When the matching thickness is 2 mm, the RL min of NPC/Co/CoO-10/700–30 wt% achieved − 48.97 dB at 13.52 GHz, and the effective absorption bandwidth exceeds 5.36 GHz. The composites with excellent performance prepared by a controllable process using chitosan and ZIF-67 might be a promising alternative for the large-scale preparation of high-frequency electromagnetic wave absorbers.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 99
·97055-97062
·
IF 3.289
Shan Fan,Wen Wang,Hua Ke,Jian-Cun Rao,Yu Zhou
A heterostructured Co3O4/CoFe2O4 nanocomposite material is synthetised via the solid–solid reaction of an iron precursor with urchin-like Co3O4 which was prepared via hydrothermal treatment. The coupling of Co3O4 to the hard ferrimagnet CoFe2O4 leads to reinforcement for the magnetic interaction of the interfaces and the mismatched surface spin in the Co3O4/CoFe2O4 nanocomposite is greatly reduced. The magnetic performance of the exchange-coupled anti-ferromagnetic/ferrimagnetic (AFM/FM) system is investigated with superconducting quantum interference device magnetometry. In an applied magnetic field, the low-temperature magnetization loops of the nanocomposite heterostructure exchange bias under cooling. The antiferromagnetic ordering temperature of Co3O4 is increased owing to the adjacent hard magnetic CoFe2O4 phase. The Co3O4/CoFe2O4 nanocomposite behaves as an exchange coupled system with cooperative magnetic switching.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yingdong Wu,Yan Wang,Pei Zhu,Xiao Ye,Ruonan Liu,Wangfeng Cai
Effective controllable manufacturing oxygen vacancy and polypyrrole coating can optimize the capacitive and cyclic properties of Co 3 O 4 . Herein, composition of O v -Co 3 O 4 @PPy with Co 3 O 4 rich in oxygen vacancy defects and polypyrrole was synthesized using NaBH 4 reduction and chronoamperometry. O v -Co 3 O 4 was synthesized while regulating the concentration of the reducing agent NaBH 4 solution, and then O v -Co 3 O 4 @PPy was synthesized by electrodeposition of PPy. The specific capacitance of O v -Co 3 O 4 @PPy formed at an optimal NaBH 4 concentration and electrodeposition time was about three times that of Co 3 O 4 without reduction treatment and unwrapped PPy. The capacitance retention rate of O v -Co 3 O 4 @PPy was close to 80.5% after 5000 cycles. In addition, O v -Co 3 O 4 @PPy//AC asymmetric supercapacitor was assembled with the as-prepared O v -Co 3 O 4 @PPy as the positive electrode material and activated carbon as the negative electrode, which yielded specific energy density up to 74.55 Wh kg −1 at 850 W kg −1 power density and a capacitance retention rate close to 110% after 10,000 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）