APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Bowen Zhang,Chongyang Wang,Saisai Zhang,Xiangli An,Zhiyong Zhao,Hari Bala,Zhanying Zhang
In this work, highly regular TiO 2 array films consisting of nanorods with a diameter of ∼119 nm were grown on FTO via a facile hydrothermal method. Then Pt nanoparticles with a size of ∼5 nm were modified on the surface of TiO 2 nanorods via an in-situ reduction process. The gas-sensing performances of pristine TiO 2 and Pt-modified TiO 2 samples were systematically tested. The introduction of Pt nanoparticles could enhance the response and stability toward CO gas and decrease the optimal operating temperature from 400 °C to 360 °C. And the Pt/TiO 2 -based sensor with a Pt content of 1.5 wt% exhibits the maximum CO sensitivity. Furthermore, the adsorption energies of Pt-modified or Pt-doped TiO 2 for CO molecules were calculated using first-principles calculations. The chemical sensitivity of Pt to CO molecules may be responsible for the improved CO sensitivity. Additionally, the unique nanorod array structure of Pt/TiO 2 and the nano-Schottky junction generated between them are helpful in enhancing the gas-sensing property.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Ke Wang,Pengfei Zhao,Ting Zhou,Yanjun Wu,Tianyu Wang,Paul S. Fennell,Edward J. Anthony
CO 2 capture and utilization to produce value-added fuels and chemicals offers a promising avenue to assist in the mitigation of the global warming crisis. However, there are economic challenges for the regeneration of some sorbents used in CO 2 capture, owing to sorbent sintering and high energy requirements, while direct conversion processes are hindered by the lack of cost-effective, efficient, selective, and stable catalysts. We demonstrate the use of sodium zirconate-looping (NaL) with the reverse-Boudouard (RB) reaction enabling high-temperature CO 2 capture and in-situ CO 2 conversion operating in a single isothermal reactor operating at 800 °C. While employing a mild combustion synthesis method, the dual-function material Na 2 ZrO 3 exhibited a high and stable CO 2 uptake capacity of 4.9 mmol CO 2 /g without the use of Ni catalysts. This is due to its fine particle size, macroporous structure, and well-dispersed ZrO 2 stabilizer within the Na 2 O matrix. The resulting Na 2 CO 3 -ZrO 2 and regenerated Na 2 ZrO 3 phases (as synergistic self-catalysts) mixed with renewable and cost-effective biochar (as a reductant) facilitated exceptional in-situ CO 2 conversion efficiency (~90 %), as well as high CO selectivity (approaching 100 %), and relative stability (~80 %) even after multiple cycles. Importantly, theoretical calculations aligned with mechanistic studies revealed that the activation energy barriers at two specific oxygen sites for the monatomic C-assisted CO 2 dissociation/gasification were lower than the desorption energy of CO 2 on the Na 2 ZrO 3 (101) surface, demonstrating the self-catalytic mechanism. Thus, this cost-effective and energy-efficient strategy provides a compelling prospect to make local emissions from large stationary sources CO 2 neutral without requiring carbon sequestration.
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Chenglong Wen,Mohong Lu,Mengyang Zhao,Jie Zhu,Mingshi Li,Jian Shang,Yuhua Shan,Chunshan Song
CeO2 with three different morphologies of nanorods (CeO2-r), particles (CeO2-p), and cubes (CeO2-c) was prepared, and the guaiacol hydrodeoxygenation over their corresponding Co-based catalysts was performed at 160–220 °C, 2 MPa, a H2 flow rate of 80 mL/min, and a weight hourly space velocity of 0.7 h–1. Compared with Co/CeO2-p and Co/CeO2-c, Co/CeO2-r has smaller Co particle sizes, a higher Brunauer–Emmett–Teller surface area, and larger amount of Co active centers, oxygen vacancies, and weak acid sites. These better physicochemical properties for Co/CeO2-r provide more Co active sites for guaiacol hydrodeoxygenation, favor the adsorption and activation of guaiacol, and contribute to the cleavage of C–O. Therefore, Co/CeO2-r presents a maximum guaiacol conversion of 97.1% and the highest yield of cyclohexanol of 91.7% among these catalysts. The result shows that the shape structure of CeO2 has an important influence on the guaiacol hydrodeoxygenation performance over its corresponding catalysts.
研究领域:
催化化学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Jing Wang,Tianqinji Qi,Zhibin Li,Wei She,Xuewei Li,Jingfang Li,Pengfei Yan,Weizuo Li,Guangming Li
Three novel N-doped carbon supported Co/Co 3 O 4 catalysts, namely, Co@CN- hmta , Co@CN- larg and Co-Co 3 O 4 @CN- bipy , with sheet-, worm-, honeycomb-like morphologies respectively, have been fabricated by the pyrolysis of well-defined coordination polymers (CPs). Upon the as-prepared catalysts were applied for the reaction of N-alkylation of nitroarenes with ethanol, a direct two-step tandem reaction is realized, in which the Co@CN- hmta delivers 100% conversion/selectivity of N-ethylaniline/N , N-diethylaniline from the direct N-alkylation of nitroarenes with ethanol. The kinetic studies were conducted to confirm that the N-alkylation of aniline with ethanol is the rate-determining step in the two-step tandem reaction. The SEM/EDX, XRD, Raman, TEM, XPS, and CO 2 -TPD characterization results have revealed that sizes and dispersion of metallic Co, amount of structural defects and surface Lewis basicity towards three catalysts can be tuned by changing the structures of Co-based CPs designed by different organic linkers, which may also help to understand the preparation of industrial catalysts on a molecular level. The optimized Co@CN- hmta catalyst is easily recycled by using the external magnet for successive reuses without any loss in both activity and selectivity. To the best of our knowledge, this is the first carbon-nitrogen species supported Co/Co 3 O 4 catalysts derived from the CPs, which could effectively catalyzed the N-alkylation of nitroarenes with ethanol to produce the secondary amines and/or tertiary amines. This low-cost, recyclable and easy scale-up N-doped carbon supported catalyst may be of potential application in various heterogeneous catalytic reactions.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2015
·
IF 4.762
Dengrong Sun,Fangxiang Sun,Xiaoyu Deng,Zhaohui Li
Different amounts of Co-substituted Ni-MOF-74 have been prepared via a post-synthetic metal exchange. Inductively coupled plasma mass spectrometry, powder X-ray diffraction (XRD), N2 adsorption/desorption, and extended X-ray absorption fine structure (EXAFS) analyses indicated the successful metathesis between Co and Ni in Ni-MOF-74 to form the solid-solution-like mixed-metal Co/Ni-MOF-74. It was found that introduction of active Co into the Ni-MOF-74 framework enabled the inert Ni-MOF-74 to show activity for cyclohexene oxidation. Since Co was favorably substituted at positions more accessible to the substrate, the mixed-metal Co/Ni-MOF-74 showed superior catalytic performance, compared with pure Co-MOF-74 containing a similar amount of Co. This study provides a facile method to develop solid-solution-like MOFs for heterogeneous catalysis and highlights the great potential of this mixed-metal strategy in the development of MOFs with specific endowed functionalities.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
Science China-Chemistry
·
2022
·Vol. 65
·期 10
·2038-2044
·
IF 10.138
Wang Yanan,Pei Chunlei,Zhao Zhi-Jian,Gong Jinlong
Rational design and performance promotion are eternal topics and ultimate goals in catalyst preparation. In contrast, trial—and—error is still the common method people take. Therefore, it is important to develop methods to intrinsically enhance the performance of catalysts. The most effective solutions are the one from a kinetic perspective based on clear knowledge of the reaction mechanism. This paper describes rate-determining step cognition and modulation to promote CO oxidation on highly dispersed Pt on CeO 2 . The different degrees of metal—support interactions due to variation of hydroxyl density of support could alter the structure of active species and the ability of oxygen activation apparently, further shift the rate-determining step from oxygen activation to oxygen reverse spillover kinetically. The transformation of rate-determining step could enhance the intrinsic activity significantly, and decrease the T 50 approximately 140 °C. The findings of this research exemplify the universal and effective method of performance elevation by rate-determining step modulation, which is promising for application in different systems.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2024
·Vol. 154
·期 7
·3787-3797
·
IF 2.3
Han Zhaohao,Chu Qingyan,Wang Hao,Jia Xiaoqiong,Jiang Peng,Li Tong
We successfully synthesized a bifunctional alkaline catalyst (Co@CTS-1), on the one hand, which demonstrates exceptional catalytic performance in the aerobic oxidation of alkenes, particularly in the epoxidation of styrene, in the absence of both an initiator and a co-reducing agent, achieving a conversion rate of 74.94%, a selectivity of 71.84% for styrene oxide; on the other hand, the catalyst maintained its high activity throughout a cyclic reaction run lasting up to 2500 min, demonstrating exceptional stability in the epoxidation of styrene. The Co@CTS-1 catalyst utilizes TS-1 as the carrier, and it is modified with cobalt and cerium elements. Through the embedding of cobalt elements within the TS-1 cage, the catalyst gains the ability to activate O 2 , and by inserting cerium elements into the atomic positions of silicon, the conversion rate is further enhanced. This encapsulated structure stabilizes cobalt nanoparticles, overcoming the short lifespan issues caused by sintering and leaching in conventional supported catalysts. This work provides practical clues for the development and application of novel catalysts, and will inspire the advancement of olefin air epoxidation. Graphical
研究领域:
催化化学
·
材料科学
·
化学工程
·
无机化学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2024
·
IF 1.8
Li Tian,Ronghua Chen,Yabin Zhang,Qiang Zheng,Xingyu Wang,Jiang Tan,Junhong Guo,Bo Mu,Xuemei Bao
A functionalized cross-linked polyphosphazenes microsphere (Salen-PZN-Ni@Co-MOF) was fabricated by enveloping Salen-Ni-based polyphosphazenes (Salen-PZN-Ni) with a type of hybrid flame retardant (Co-MOF) to enhance the flame retardant, smoke suppression properties and mechanical properties of epoxy (EP) composites. Thermogravimetric analysis indicated that the incorporation of Salen-PZN-Ni@Co-MOF significantly enhanced the thermal stability of the EP composites. The existence of Salen-PZN-Ni@Co-MOF enhanced both the vertical burning rating and resulted in a higher limiting oxygen index. The addition of 5 wt% Salen-PZN-Ni@Co-MOF conspicuously improved the fire safety of EP, as evidenced by the results of the cone calorimeter. For instance, the peak heat release rate and total heat release rate of the EP composites were decreased by 25.3% and 44.97%, respectively. In addition, the incorporation of Salen-PZN-Ni@Co-MOF significantly inhibited the generation of toxic carbon monoxide and other volatile compounds. Furthermore, a synergistic effect between Salen-PZN-Ni and Co-MOF was observed. The proposed flame retardant mechanism of Salen-PZN-Ni@Co-MOF is attributed to the synergistic catalytic carbonization effect and the formation of thermally stable components. Consequently, enhanced fire safety in EP composites is achieved through the synergistic interaction among various components (nickel and Co-MOF) with polyphosphazene microspheres. Meanwhile, the excellent compatibility between Salen-PZN-Ni@Co-MOF and EP enhances the mechanical properties of EP composites.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 17
·5467-5474
·
IF 7.367
Yue Sun,Yunjie Zhou,Cheng Zhu,Lulu Hu,Mumei Han,Aoqi Wang,Hui Huang,Yang Liu,Zhenhui Kang
Highly efficient electrocatalysts remain huge challenges in direct methanol fuel cells (DMFCs). Here, a Pt–Co3O4–CDs/C composite was fabricated as an anode electrocatalyst with low Pt content (12 wt%) by using carbon dots (CDs) and Co3O4 nanoparticles as building blocks. The Pt–Co3O4–CDs/C composite catalyst shows a significantly enhanced electrocatalytic activity (1393.3 mA mg−1 Pt), durability (over 4000 s) and CO-poisoning tolerance. The superior catalytic activity should be attributed to the synergistic effect of CDs, Pt and Co3O4. Furthermore, the Pt–Co3O4–CDs/C catalyst was integrated into a single cell, which exhibits a maximum power density of 45.6 mW cm−2, 1.7 times the cell based on the commercial 20 wt% Pt/C catalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Powder Materials
·
2023
·
IF 0
Cheng Li,Yatian Deng,Liping Yang,Bo Liu,Dong Yan,Liyuan Fan,Jian Li,Lichao Jia
Sr 2 FeCo 0.2 Ni 0.2 Mo 0.6 O 6-δ (SFCNM) and Sr 2 FeNi 0.4 Mo 0.6 O 6-δ (SFNM) were prepared as the hydrogen electrode materials for solid oxide cells (SOCs) and comparatively investigated by density function theory (DFT) and experiments to demonstrate the benefit of Co addition. The reduced SFCNM (R-SFCNM) and SFNM (R-SFNM) contain exsolved Fe–Co–Ni and Fe–Ni nanoparticles, respectively. DFT indicates that Fe–Co–Ni has optimized combination of the d-band center (descriptor of catalyst activity) and adsorption behavior for H 2 O, H 2 , H, and OH. The cell with SFCNM hydrogen electrode, La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM) electrolyte, and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) oxygen electrode (Cell-SFCNM) demonstrates a higher performance than that with an SFNM hydrogen electrode (Cell-SFNM) at temperatures between 700 and 850 °C in both solid oxide fuel cell (SOFC, 3% H 2 O-97% H 2 /air) and solid oxide electrolysis cell (SOEC, 20% H 2 O-80% H 2 /air) modes. At 850 and 700 °C, the peak power density is 1.23 and 0.48 W·cm −2 in SOFC mode, while the current density is 1.25 and 0.37 A·cm −2 at 1.3 V in SOEC mode, respectively. The performance degradation rates at 750 °C are 0.17 mV·h −1 in SOFC and 0.15 mV·h −1 in SOEC modes within 150 h, which are improved by Co doping.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
FUEL
·
2023
·
IF 7.4
Jie Yu,Zhuoran Hou,Huayu Zhang,Xinsheng Zhou
The fabrication of electrode materials with a high specific capacitance is essential for the development of enhanced performance supercapacitors. A novel binder-free electrode material, composed of MnS/Ni 3 S 2 and Co(OH) 2 , was synthesized on nickel foam by hydrothermal, sulfuration, and electrodeposition techniques. The MnS/Ni 3 S 2 exhibited a unique flower-like structure, resulting in a high specific capacitance of 1780 F g −1 at 1 A/g. By optimizing the synthesis conditions through several characterization and electrochemical tests, the MnS/Ni 3 S 2 @Co(OH) 2 composite was obtained, which displayed an ultrahigh specific capacitance of 2495 F g −1 at 1 A/g and a capacitance retention rate of 86.1% after 5000 cycles at 10 A/g in three-electrode system. The synergistic coupling of MnS/Ni 3 S 2 and Co(OH) 2 , along with the conductive nickel foam substrate, donated towards the excellent electrochemical performance. Furthermore, the MnS/Ni 3 S 2 @Co(OH) 2 //AC asymmetric supercapacitor (ASC) device was constructed with MnS/Ni 3 S 2 @Co(OH) 2 as positive electrode, activated carbon (AC) as negative electrode and 1 M KOH solution as electrolyte, demonstrated a high energy density of 68.6 Wh kg −1 at 750 W kg −1 and excellent cycle stability with 91.2% capacitance retention after 10,000 cycles at 15 A/g. The outstanding electrochemical properties observed in both the pre-electrodeposition and post-electrodeposition samples indicate the effectiveness of reasonable design and construction of composite as a pathway for producing electrode materials with exceptional performance.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2023
·Vol. 26
·期 4
·557-565
·
IF 3.1
Jiaqiang Ding,Bingyu Xiao,Jinqiu Wu,Dongliang Chen,Dongling Huang,Zuochun Xiong
Poly(ε-caprolactone-co-trimethylene carbonate) (PCLTMC) is a biodegradable copolymer, which is widely used for medicine and tissue repair systems, and its morphology, degradation and mechanical properties have been extensively investigated. However, its crystallization behavior with different copolymerization ratios has not been studied systematically, which is of great significance for the study of property regulation and an understanding of the crystallization behavior of random copolymers. In this paper, the relationship between the crystallization temperature Tc, melting point temperature Tm and crystallinity Xc of copolymers with different molar ratios was determined by differential scanning calorimetry (DSC) using a non-isothermal crystallization method. The results show that the melting point and crystallinity of the copolymer decrease with an increase in TMC composition. The equilibrium melting point of the copolymers was predicted by an isothermal crystallization method, using the Hoffman–Weeks extrapolation method and crystallization rate growth fitting method both based on Lauritzen–Hoffman theory. It is proved that Lauritzen–Hoffman theory is of great significance for guiding the kinetic behavior of PCLTMC crystallization.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）