CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Hao Xu,Hongxia Zhang,Lin Cui,Xinshuo Zhao,Jiao Xiao,Jian Zhang,Yong Qin,Jiankang Zhang
Constructing high-efficiency catalysts with high activity and selectivity is the long-term pursuit in heterogeneous catalysis field. Metal–oxygen vacancy (Ov) synergy provides a promising route to realizing the goal. In this study, the Pt/CoO x catalysts with Pt–Ov dual sites are designed by atomic layer deposition (ALD) for selective hydrogenation of cinnamaldehyde, and the Ov property, Pt size and the spatial relationship of Pt and CoO x can be well modulated. Experimental and theoretical investigations indicate that the substrate and hydrogen can be activated on Ov and Pt nanoparticles, respectively. The Ov introduced by ALD not only preferentially activates C O bond of CALD to achieve high selectivity to CALA, but also enhances the ability to dissociate hydrogen on Pt nanoparticles through Pt-Ov electron transfer. Importantly, the optimized Pt40/CoO x -Ov catalysts with suitable Ov coordination and Pt sizes (2.5 nm) show lower adsorption energy for reactant molecules, obtaining significantly enhanced activity with a turnover frequency value of 202.5 mol CALD ·mol Pt -1 ·min −1 and obviously improved selectivity of desired products (93 %). This work offers a fundamental understanding of Pt–Ov synergy toward hydrogenation of unsaturated compounds.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·
IF 13.3
Shuyang Peng,Di Liu,Keyu An,Zhiqin Ying,Mingpeng Chen,Jinxian Feng,Kin Ho Lo,Hui Pan
Green hydrogen is considered to be the key for solving the emerging energy and environmental issues. The photoelectrochemical (PEC) process for the production of green hydrogen has been widely investigated because solar power is clean and renewable. However, mass production in this way is still far away from reality. Here, a Si photoanode is reported with CoO x as co-catalyst for efficient water oxidation. It is found that a high photovoltage of 350 mV can be achieved in 1.0 m K 3 BO 3 . Importantly, the photovoltage can be further increased to 650 mV and the fill factor of 0.62 is obtained in 1.0 m K 3 BO 3 by incorporating Mo into CoO x . The Mo-incorporated photoanode is also highly stable. It is shown that the incorporation of Mo can reduce the particle size of co-catalyst on the Si surface, improve the particle-distribution uniformity, and increase the density of particles, which can effectively enhance the light absorption and the electrochemical active surface area. Importantly, the Mo-incorporation results in high energy barrier in the heterojunction. All of these factors are attributed to improved the PEC performance. These findings may provide new strategies to maximize the solar-to-fuel efficiency by tuning the co-catalysts on the Si surface.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 27
·11557-11565
·
IF 3.288
Chao Miao,Junjie Liu,Jinxian Zhao,Yanhong Quan,Tao Li,Yongli Pei,Xiaoliang Li,Jun Ren
A rational approach for the optimization of cobalt based catalysts suitable for VOC combustion is to modulate the pore structure and increase the dispersion of active species. In this study, we have prepared CeO2–CoOx composite aerogels with a continuous porous structure using an epoxide-initiated gelation process and evaluated them in the catalytic combustion of toluene. The influence of the Ce/Co ratio on the structural properties and catalytic activities of the CeO2–CoOx aerogels was investigated using various characterization methods. The surface area of the CeO2–CoOx aerogels showed a volcanic curve versus the Ce content. A higher specific surface area of 172 m2 g−1 was observed for the CeO2–CoOx-10 catalyst with a Ce/Co ratio of 1/10. In addition, the presence of Ce modified the redox properties and the surface chemical states of the CeO2–CoOx aerogels, such as the surface Co3+/Co2+ ratios, and surface absorbed oxygen species (O− and O2−), which played key roles in their catalytic activity. In comparison with different cobalt-based catalysts for toluene oxidation in the previous literature studies, the CeO2–CoOx-10 catalyst in this work exhibited better catalytic performance, reaching an optimal toluene conversion of 90% at 248 °C as well as the highest stability during the durability test under different temperature stages.
研究领域:
材料科学
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环境催化
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 11
·期 1
·316-329
·
IF 14.511
Jinxian Feng,Lulu Qiao,Pengfei Zhou,Haoyun Bai,Chunfa Liu,Chon Chio Leong,Yu-Yun Chen,Weng Fai Ip,Jun Ni,Hui Pan
Hydrogen evolution reaction (HER) is a vital step for green-hydrogen production in commercial alkaline water electrolyzers. Although various electrocatalysts have been developed, the relationship between the structure and HER activity has not been clearly understood. Herein, we report nanocrystalline CoOx glass composed of mixed amorphous parts and crystalline domains on Ni foam (NF) (denoted as (10CeCrP)CoOx–NF–HER) for alkaline HER. We find that (10CeCrP)CoOx–NF–HER exhibits high catalytic activity (for example, −0.354 V at 200 mA cm−2 without iR correction) and good stability at high current density. Our experimental results reveal that the synergistic effects between the nanocrystalline domains and amorphous matrix improve the HER kinetics dramatically because: (1) the amorphous CoOx enhances the pseudocapacitive K+ adsorption, leading to high surface water affinity, (2) the mixed crystalline and amorphous structure improves the stability of CoOx in the HER process, leading to long-term catalytic stability, and (3) the high water and hydrogen concentrations on its surface provide abundant feedstocks for HER and promote the hydrogen transportation and conversion. Our findings may provide an insightful understanding for the enhanced catalytic performance of poor-crystalline electrocatalysts in HER, and open a new avenue for the design of high-performance HER electrocatalysts.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2025
·Vol. 54
·期 8
·3467-3477
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IF 3.3
Wenhui Hu,Zhongxin Song,Lingna Sun,Lei Zhang,Qianling Zhang,Xiangzhong Ren,Yongliang Li
Efficient separation of photogenerated charge carriers is essential for maximizing the photocatalytic efficiency of semiconductor materials in oxygen evolution reactions (OER). This study presents a novel trimetallic photocatalyst, MIL-100(Fe)/TiO2/CoOx, synthesized through a facile microwave-assisted hydrothermal method followed by atomic layer deposition (ALD). The porous MIL-100(Fe) serves as a support for the sequential deposition of TiO2 and CoOx layers via ALD, which enhances electron–hole pair separation and minimizes their recombination. Characterization using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirms the uniform deposition of TiO2 and CoOx layers on the MIL-100(Fe) surface. The optimized photocatalyst, processed with 20 deposition cycles of Co, exhibits exceptional photocatalytic OER performance, with an oxygen evolution rate of 558.3 μmol g−1 h−1. This enhancement in activity is attributed to the synergistic interaction between the spatially separated TiO2 and CoOx cocatalysts, which facilitates efficient charge transfer and increases the number of active sites. These findings highlight the potential of ALD-fabricated heterostructures in the development of advanced photocatalysts for sustainable energy production.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Hairong Tang,Yong He,Peixi Liu,Jiaming Shao,Fawei Lin,Zhihua Wang
Zeolitic-imidazolate framework precursors (ZIF-67) were synthesized in an inorganic solution with triethylamine as a deprotonating agent for N2O decomposition, and the catalytic activities of the pyrolysis products under different conditions were investigated. Among them, the Co/CoOx@carbon catalyst pyrolyzed at 650 °C in a N2 atmosphere (Co-650N) exhibited excellent low-temperature catalytic activity and stability, achieving 50% decomposition efficiency at 305 °C and ∼100% at 400 °C, which benefitted from its large specific surface area, great reduction performance, abundant cobalt active sites, and surface oxygen species. Further, utilizing temperature-programmed desorption (TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS) results, it was found that N2O molecules preferentially combined with oxygen species bound to cobalt sites. The absorbed N2O was decomposed into N2 and oxygen species, and the latter was subsequently transferred to carbon frameworks. Interestingly, the amorphous graphitic carbon frameworks played an important role in transferring/storing active oxygen and regenerating cobalt sites. Moreover, Co-650N exhibited better resistance to SO2, and the efficiency could be recovered via heating and finally stabilized at 100%. Finally, the mechanisms of N2O decomposition and sulfur poisoning-reactivation on Co/CoOx@carbon catalysts were proposed for the first time.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
International Journal of Environmental Science and Technology
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2020
·Vol. 17
·期 5
·3055-3064
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IF 2.54
Liu S.-S.,Luo D.-M.,Yang X.,Tong C.-X.,Tao L.-G.,Ding H.-P.,Zhang J.
A series of graphitic carbon nitrides (g-C 3 N 4 ) were prepared using different precursors; these g-C 3 N 4 -supported CoOx catalysts exhibited different catalytic performances in toluene catalytic combustion reaction. The structure of samples was detected by XRD, TEM, SEM, XPS, H 2 -TPR, nitrogen adsorption and desorption technique, to build up the structure–performance relationship and uncover the key property of g-C 3 N 4 that mostly influences the catalytic performance of CoOx/g-C 3 N 4 . CoOx with average particle size of 12.7 nm supported on g-C 3 N 4 prepared by dicyandiamide showed better catalytic performance than on other supports, 100% toluene conversion could be achieved at ~ 285 °C, characterization results showed that Co was directly connected with N, and the integrity of g-C 3 N 4 sheet affects the dispersion of CoOx; the content of sp 2 -N (within C=N–C structure) determines the interaction between g-C 3 N 4 and CoOx; these two factors together affect the performance of CoOx/g-C 3 N 4 catalysts in the catalytic combustion of toluene.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Shujian Wang,Chunzheng Wu,Hongbo Yu,Tong Li,Xuedong Yan,Bo Yan,Hongfeng Yin
Nanosized Ir catalysts suffer from serious side reactions and poor stability during hydrogenation of substituted nitroaromatics to produce aromatic amines. In this work, core–shell nanostructures with sub-4 nm Ir-CoOx hybrid cores and mesoporous SiO2 shells were designed and prepared to overcome these problems. The Ir-CoOx hybrid cores were converted from IrCo alloy nanoparticles (NPs) inside SiO2 through in situ calcination and reduction pretreatments. The SiO2 mesoporous shells in Ir-CoOx@SiO2 nanoreactors prevented the agglomeration/sintering of IrCo NPs, while allowing the free reactants and products (big molecules). The synergy between Ir and CoOx species improved H2 adsorption, thus affecting the reaction rate as well as the selectivity to aromatic amines. As a result, the obtained Ir-CoOx@SiO2 nanocatalyst showed tremendous improvement in catalytic activity, selectivity, and stability.
研究领域:
材料科学
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化学工程
·
催化反应
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2020
·
IF 4.632
Xiao Zhang,Yaohua Xu,Hao Liu,Wenrui Zhao,Anjie Ming,Feng Wei
A homogeneous porous Co 3 O 4 -ZnO nanomaterial (Zn-CoO x ) was successfully fabricated by precipitation-annealing route. The as-prepared Zn-CoO x exhibited good response, reliable reversibility and good selectivity towards alcohols, which attributed to the porous structure and p-n heterojunction formed between Co 3 O 4 and ZnO. In particular, the different Fermi levels of Co 3 O 4 and ZnO leaded to a further increase the depth of the space charge layer, which improved the gas sensitivity of the material from 10% to 480%. Besides, the continuous Co 3 O 4 leaded to a relatively lower operating temperature and resistance. This material preparation method and bimetallic oxides could be widely used in the research and development of metal oxide gas sensitive materials and sensors.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Yuqian Wang,Defeng Zhou,Weiyi Zhang,Jie Yang,Qingyuan Sheng,Xiaofei Zhu,Jinghe Bai
The advancement and application of mesophilic solid oxide fuel cells (IT-SOFCs) rely heavily on enhancing cathode materials to achieve greater efficiency. In this paper, Pr 0.4 Sr 0.6 Co 0.2 Fe 0.8 O 3-δ (PSFC) and transition metal oxide CoOx were selected as cathode materials, which not only combined the high catalytic activity of Pr 6 O 11 but also took advantage of the structural stability and economy of Fe-based perovskite. The samples underwent analysis using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and X energy dispersion spectrometer (EDS) for structural examination. The electrochemical workstation was used to test the conductivity of the material and the stability of the cell. The results indicate that an appropriate amount of CoO X composite can effectively enhance the level of oxygen vacancies, thereby enhancing the ORR activity of the cathode. Among these composites, Pr 0.4 Sr 0.6 Co 0.2 Fe 0.8 O 3-δ -CoO x -I exhibits the fastest rate of oxygen exchange at the surface and the best electrochemical performance. At 700 °C, the polarization resistance ASR of Pr 0.4 Sr 0.6 Co 0.2 Fe 0.8 O 3-δ -CoO x -I is 0.0749 Ω cm 2 ; In single-cell fuel mode with NiO-YSZ as anode, YSZ electrolyte, and GDC as cell layer, the peak power density (PDD) is 0.97W cm −2 . The PSCF-CoO x composite cathode holds promise as a high electrocatalytic active material for Solid Oxide Fuel Cells (SOFCs).
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 29
·18204-18213
·
IF 10.7
Qingsheng Zhang,Shuya Yuan,Huabing Yin,Jianjun Yang,Zhongjie Guan
The photocatalytic pure water splitting performance of photocatalysts is still restricted by the low utilization efficiency of photogenerated holes. Recent studies suggest that metal oxide clusters can efficiently abstract holes from a bulk photocatalyst via discrete energy bands. However, the decay dynamics of excited states in such a heterostructure have not been explored. Herein, ultra-small CoOx clusters decorated on ZnIn2S4 (ZIS) are prepared for pure water splitting. Experimental characterization studies confirm that CoOx clusters efficiently capture holes from ZnIn2S4, thus inhibiting charge recombination. Femtosecond transient absorption spectroscopy (fs-TAS) reveals that the lifetime of holes trapped by CoOx clusters is prolonged to 911.6 ps, enabling more opportunities to participate in the surface reaction. Moreover, density functional theory calculation suggests that the CoOx cluster is the preferential adsorption site for H2O to boost surface water oxidation. Benefiting from the above factors, the optimized CoOx/ZIS shows improved H2 and H2O2 evolution rates of 404.1 μmol g−1 h−1 and 371.9 μmol g−1 h−1 under visible light irradiation, respectively, which are about ten times higher than that of pure ZIS. The study highlights the significance of efficient hole extraction for improving photocatalytic pure water splitting performance.
研究领域:
材料科学
·
光催化
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Jing Zhao,Hucheng Zhang,Haiyan Wang,Jianji Wang
A highly attractive aim is to turn CO 2 into useful chemicals selectively and efficiently, but it still retains great challenging to understand the relations between catalytic performances and interface properties. Here, we report an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases on the Pd-CoO x interfaces. CoO∙TiO 2 /TiO 2 and CoO x /TiO 2 possess the wide spectrum of Lewis acid/base centres, and give the low selectivity and conversion. The introduction of Pd can focus them on the intrinsic centres, and makes Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent the ideal catalysis. With temperature-programmed desorptions of CO 2 , CO and NH 3 , it is evidenced that the catalytic hydrogenations of CO 2 to CO, CH 4 and CH 3 OH depend on the cooperation of the Lewis acidic/alkaline centres on the interfaces. The studies provide guidelines for rational design and synthesis of heterogeneous catalysts including but not limited to CO 2 hydrogenation.
研究领域:
化学工程
·
催化科学
✓ 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）