APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Na Ye,Pengcheng Zhao,Xiaoying Qi,Riguang Zhang,Binhang Yan,Wenchao Sheng,Zhao Jiang,Tao Fang
Engineering high-performance inexpensive TaN-modified Pd-based nanostructures for alkaline methanol oxidation reaction(MOR) has attracted extensive attention, yet the related enhancement mechanism of TaN for MOR remains lacked. The core-shell like Pd 3 Ni 1 -TaN/C catalyst decorated with Ni(OH) 2 /NiOOH that contains highly dispersed Ni sites and nitrogen defects has been fabricated for the first time. The unsaturated coordination environment and core-shell like morphology of Pd 3 Ni 1 -TaN/C bring fruitful active sites and a down-shifted d -band center, making it a highly-efficient electrocatalyst for alkaline MOR (17.3-fold that of commercial Pd/C). Besides the electronic effects and surface defect sites of Pd 3 Ni 1 -TaN/C, TaN also helps MOR proceed via HCOO ad pathway (non-CO) accompanied by enhanced OH adsorption induced by the addition of Ni. DFT(Density Functional Theory) calculations also further confirm the energy barrier of the formation of HCOO ad intermediate and desorption energy of CO on Pd 3 Ni 1 -TaN/C are reduced. The introduction of Ni species and nitrogen vacancies enhances the CO tolerance evidently.
研究领域:
材料科学
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电化学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Shan-Lu Chen,Wei-Ming Guo,Shi-Kuan Sun,Yuji Masubuchi,Ming Lv,Hua-Tay Lin,Cheng-Yong Wang
In this work, nearly single phase SrTaO 2 N powder was directly prepared from strontium carbonate (SrCO 3 ) and tantalum mononitride (TaN), instead of the nitridation of the oxide precursors using NH 3 . The phase evolution and reaction mechanism together with the chemical composition, crystal structure and particle size of SrTaO 2 N product were investigated. Similar to the reactions between SrCO 3 and Ta 3 N 5 , the evolution of CO 2 , CO and N 2 was detected during the reactions. The results revealed that this novel reaction was able to successfully synthesize orange-coloured SrTaO 2 N powder with nearly pure phase at 1200 °C and the powder possessed the uniform size distribution with the mean diameter of 6.63 µm.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 21
·30039-30042
·
IF 4.527
Leihao Feng,Qiwei Hu,Li Lei,Lei Qi,Leilei Zhang,Meifang Pu,Zili kou,Fang Peng,Duanwei He,Yohei Kojima,Hiroaki Ohfuji,Tetsuo Irifune
High-hardness TaN compacts with a diameter and height of 6 mm were synthesized through the phase transformation of CoSn-type into WC-type TaN under experimental conditions of high temperature and high pressure . The Vickers hardness of WC-type TaN compacts obtained at the pressure of 5 GPa and the temperature of 1873 K is found to be ~21.5 ± 1.5 GPa with a load of 3 Kg, which is comparable to that of the pure tungsten carbide compact (~20 GPa) and higher than those of ultrahigh temperature ceramics ZrB 2 and HfB 2 under the same load. The high hardness of WC-type TaN compacts presented in this work is attributed to the deviatoric strain and well-bonded nanograins . The synthesized WC-type TaN compacts also possess a high oxidation temperature (1072 K). These results suggest that the WC-type TaN with high hardness and high thermal stability holds great promise for industrial applications.
研究领域:
材料科学
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无机非金属材料
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超硬材料
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高温材料
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固态化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Na Ye,Pengcheng Zhao,Xiaoying Qi,Wenchao Sheng,Zhao Jiang,Tao Fang
The C C bond cleavage remains a main challenge for alkaline EOR (ethanol oxidation reaction). In this work, we report an efficient PdSn-TaN/C electrocatalyst to split the C C bonds in ethanol. Structurally, a series of characterization results confirm the presence of the low-coordinated Pd sites on the PdSn-TaN/C interface. The PdSn-TaN/C catalyst exhibits very high activity (almost 26.9 times of commercial Pd/C), good durability and high selectivity to CO 2 (20.5%) towards alkaline EOR. Specifically, in-situ ATR-SEIRAS (Attenuated total reflection-surface enhanced infrared absorption spectroscopy) results indicate that TaN facilitates the cleavage of C C bonds, whereas Sn promotes the further oxidation of ethanol fragments. DFT (density functional theory) calculations indicate the activation barriers of the C H bond cleavage in CH 3 CH 2 OH, CH 3 CHOH, CH 3 CHO, CH 3 CO, CH 2 CO and the C C bond cleavage in CH 3 CO, CH 2 CO, CHCO are reduced evidently and the removal of adsorbed CH 3 CO and CO becomes easier on the PdSn-TaN/C catalyst surface.
研究领域:
电化学
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催化材料
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理论计算
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Weixuan Zeng,Sheng Cao,Lulu Qiao,Anquan Zhu,Pengfei Tan,Yongjin Ma,Yuan Bian,Rui Dong,Ziyu Wang,Jun Pan
Rationally and skillfully constructing semiconductor heterostructured photocatalysts , benefited from the facilitated the carrier separation and transfer, have attracted intensive attention and been demonstrated as a manageable and effective strategy to develop high-performance photocatalysts. Herein, a novel SrTaO 2 N/Ta 3 N 5 heterostructured photocatalyst were fabricated by one-pot nitridation of Sr 2 Ta 2 O 7 /Ta 2 O 5 precursor under ammonia flow. The as-prepared SrTaO 2 N/Ta 3 N 5 is a type-II heterostructure with an intimate interface contact, and the photocatalytic hydrogen production over the optimized heterostructure SrTaO 2 N(0.1)/Ta 3 N 5 is about 14.1 times higher than that of individual SrTaO 2 N. The experimental results suggest that the formation of type-II heterostructure and intimate interface contact between Ta 3 N 5 and SrTaO 2 N accelerates the separation and transfer of electrons and holes under visible light irradiation, consequently contribute to the improved hydrogen production rate. Moreover, we highlight that one-pot nitridation has the great potential to apply as an underlying general strategy of designing and fabricating other types of high-efficiency tantalum oxynitride-based heterostructured photocatalysts.
研究领域:
材料科学
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光催化
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无机化学
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能源化学
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半导体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
·
IF 5.316
Zhuo Yu,Qichen Li,Jun Liao,Yong Zhang,Lin Zhang,Wenkun Zhu
Three kinds of nano-manganese oxide materials were prepared at different temperature (500, 600 and 700 °C) using chitosan as the template agent. The results showed that there was no sintering and agglomeration in the calcination of nano-manganese oxide at 600 °C, while the manganese oxide material calcined at 700 °C showed pore collapse and agglomeration and the template agent was incompletely removed in the manganese oxide material calcined at 500 °C. The adsorption properties of uranium (VI) on the three manganese oxide materials were investigated. The experimental results showed that the adsorption behavior conformed to the pseudo-second-order kinetics and Langmuir isotherm models, revealing that the adsorption behavior of uranium (VI) on manganese oxide materials was a uniform and monolayer chemical adsorption process . The adsorption capacity of MnO-600 was 635.4 mg/g and the adsorption efficiency was above 90% after five cycles. In conclusion, the novel manganese oxide materials would have a prospect for application in wastewater treatment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Shengnan Wang,Xu Chu,Xiaoyan Xiang,Yan Cao
This study focused on the fluorescence antenna-sensitizing effect of graphene quantum dots (GQDs) in a case on the detection of terbium ions. A simple one-step chemical oxidation method was applied for the preparation of GQDs starting from the regular multilayer graphene oxide (GO) via the refluxing in a concentrated mixture of strong acids. The as-prepared GQDs were further evaluated as a fluorescent sensitizer to the terbium ion. An expanded in-deep mechanism study on the fluorescence phenomena during the interaction of the as-prepared GQDs and REEs was made. The highly selective antenna effect of GQDs on one of REEs’ aqueous media, which was terbium (III), was identified. The excited terbium ion emitted its long-living fluorescence based on its own characteristic line-typed f-f transition, contrasting to a undetectable fluorescence in a very poor quantum yield in its aqueous solution induced by water collisions. This study, in the first place, identified the significant sensitization effect of the as-prepared GQDs on the terbium ion in a high selectivity in aqueous media. The detectable linear range and the detection limit of the terbium ion was 0–30 × 10 −6 mol L −1 (R 2 = 0.9960) of 0.3 × 10 −6 mol L −1 , respectively. The excitation wavelength and the optimal fluorescence wavelength were 230 nm 546 nm, respectively. Further material characterizations, involving XPS, FTIR, Raman and the Zeta potential , verified the important participation of carboxyl function groups on the as-prepared GQDs.
研究领域:
材料科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Na Ye,Zhao Jiang,Tao Fang
The low-palladium Pd/TaN–C catalyst is synthesized by a surfactant-free solvothermal approach and exhibits high activity (2613.18 mA mg Pd −1 ), durability and CO tolerance for MOR (methanol oxidation reaction) in alkaline media , 12.4 folds that of the commercial Pd/C. XPS and electrochemical results indicate that the interfacial Pd–TaNO bond is generated. This also brings the enhancement of OH ad adsorption responsible for anti-CO poisoning ability. Density Functional Theory (DFT) calculations indicate that the reaction pathway and the rate-determining step are changed for methanol decomposition to CO on the Pd 4 /TaN(001) surface compared with Pd (111). The preferred pathway can be described as: CH 3 OH→CH 3 O→CH 2 O→CHO→CO. Furthermore, the results indicate that the adsorption of OH is enhanced and the energy barrier of COOH formation from CO + OH is reduced with the high concentration of hydroxyl on the Pd 4 /TaN(001) surface, further confirming the bi-functional effect of hydroxyl on the CO tolerance.
研究领域:
电化学
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催化材料
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yanxin Bai,Na Ye,Zhao Jiang,Riguang Zhang,Tao Fang
Developing the efficient and durable non-platinum based electrocatalysts for methanol oxidation reaction is critical for the application of direct methanol fuel cells (DMFCs). Here, a series of Ni-based catalysts are synthesized via the microwave-assisted ethylene glycol reduction method, which couples the oxyphile metals with transition metal nitrides (TaN), to study the electrocatalytic behavior for methanol oxidation reaction in alkaline media. The results of transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that the existence of geometric and electronic effects among Ni, Cu/Sn and TaN. Electrochemical measurements indicate that NiCu-TaN/C and NiSn-TaN/C exhibit high activity with 256.02 and 224.03 mA·cm −2 , high surface coverage of redox species, abundant active sites, long-term durability and fast reaction kinetics. In situ ATR-SEIRAS results imply that methanol oxidation reaction mainly goes through the direct pathway on the synthesized catalysts. Combined with the structural characterization and electrochemical measurements, it can be found that the enhanced catalytic performance of bimetallic catalysts can be ascribed to the synergistic effect with coupling the oxyphile metals with TaN. The introduction of Cu/Sn and TaN will change the electronic structure of Ni and coverage of Ni(OH) 2 /NiOOH redox species on the catalyst surface, which modify the adsorption characteristic of reaction intermediates and formation of HCOO, CO 2 and OH species following the direct path in alkaline MOR.
研究领域:
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2023
·Vol. 15
·期 15
·e202300300
·
IF 4.5
Yanxin Bai,Hui Xiong,Zhao Jiang,Riguang Zhang,Tao Fang.
Graphical The TNNs-modified Ni/C catalysts (TM=V, Mo, Nb, Ta) exhibited higher activity, kinetics, charge transfer and stability for alkaline MOR. Ni/VN−C showed the highest catalytic activity, nearly three times higher than that of Ni/C due to the highest coverage of the surface component NiOOH. A volcano plot existed between the d-band center and activity of the corresponding catalysts. Transition metal nitrides are considered as the promising materials in the energy conversion processes due to the similar electronic structures to Pt. In this work, a series of Ni/TMN−C (TM=V, Mo, Nb, Ta) catalysts were synthesized and investigated the catalytic performance for methanol oxidation reaction in alkaline media. The electrochemical measurements indicated that the TNNs-modified Ni/C catalysts exhibited higher activity, kinetics, charge transfer and stability for alkaline MOR compared with Ni/C. It was found that the incorporation of TMNs improved the activity and stability for MOR in various degree. Specially, Ni/VN−C showed the highest catalytic activity, nearly three times higher than that of Ni/C due to the highest coverage of the surface component NiOOH, consistent with the Tafel and EIS results that it exhibited the fastest charge transfer kinetics and reaction rate. XPS characterization indicated that the obvious electron interaction occurred between the TMNs and Ni species and Ni would transfer electrons to the transition metal nitrides, resulting in the electron-rich states of TMNs. Interestingly, combining the d-band center and activity of the corresponding catalysts, it could be found that a volcano plot existed between them, suggesting that the introduction of appropriate nitrides would change the electronic structure of Ni and enhance the catalytic performance for MOR in alkaline media.
研究领域:
材料科学
·
电化学
·
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）