TRANSACTIONS OF TIANJIN UNIVERSITY
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2018
·Vol. 24
·期 6
·547-554
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IF 0
Fang Chunyu,Zhong Huixian,Wei Ying,Wang Jiaming,Zhang Siran,Zhang Lihong,Liu Yuan
A new scheme for the preparation of highly dispersed precious metal catalysts is proposed in this work. Samples of LaCo 1− x Pt x O 3 /SiO 2 ( x = 0.03, 0.05, 0.07, 0.09, and 0.10) were prepared through a simple method of citrate acid complexation combined with impregnation. In a nanocrystallite of LaCo 1− x Pt x O 3 , ions of lanthanum, cobalt, and platinum are evenly mixed at the atomic level and confined within the nanocrystallite. In the reduction process, platinum ions were reduced and migrated onto the surface of the nanocrystallite, and the platinum should be highly dispersed owing to the even mixing of the platinum ions in the precursor. When x = 0.05 or lower, the highest dispersion of Pt could be achieved. The highly dispersed Pt is stable, because of the strong interaction between Pt atoms and the support. The catalysts were characterized by BET surface area, temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, CO temperature-programmed desorption, and turnover frequency. Compared with general precious metal Pt catalysts, the LaCo 0.95 Pt 0.05 O 3 /SiO 2 catalyst exhibited better activity for CO oxidation, and it maintained stability at a high temperature of 400 °C for 250 h with complete CO conversion.
研究领域:
材料科学
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催化化学
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环境科学
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产品关联
DOI
RSC Advances
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2020
·Vol. 10
·期 28
·16515-16525
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IF 3.119
Junya Cao,Fenggang Han,Liguo Wang,Xiaoyu Huang,Yan Cao,Peng He,Huanhuan Yang,Jiaqiang Chen,Huiquan Li
A series of Ru/g-C3N4 materials with highly dispersed Ru were firstly prepared by an ultrasonic impregnation method using carbon nitride as a support. The catalysts were characterized by various techniques including BET and elemental analysis, ICP-AES, XPS, XRD, CO2-TPD and TEM. The results demonstrated that Ru/g-C3N4 materials with a mesoporous structure and highly dispersed Ru were successfully prepared. The chemo-selective hydrogenation of p-phenylenediamine (PPDA) to 1,4-cyclohexanediamine (CHDA) over Ru/g-C3N4 as a model reaction was investigated in detail. PPDA conversion of 100% with a CHDA selectivity of more than 86% could be achieved under mild conditions. It can be inferred that the carbon nitride support possessed abundant basic sites and the Ru/g-C3N4-T catalysts provided suitable basicity for the aromatic ring hydrogenation. Compared to the N-free Ru/C catalyst, the involvement of nitrogen species in Ru/g-C3N4 remarkably improved the catalytic performance. In addition, the recyclability of the catalyst demonstrated that the aggregation of Ru nanoparticles was responsible for the decrease of the catalytic activity. Furthermore, this strategy also could be expanded to the selective hydrogenation of other aromatic diamines to alicyclic diamines.
研究领域:
催化
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化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
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IF 22.1
Shujie Liang,Xiaohui Zhong,Zuqi Zhong,Hong Deng,Wai-Yeung Wong
Photoconversion of CO 2 into value-added fuels has aroused widespread interest; however, this process is significantly limited by the inefficient thermodynamics and sluggish reaction dynamics in the diluted CO 2 . To circumvent these obstacles, we design a bipyridine-based polyimide polymer for anchoring single Ni site for diluted CO 2 photoreduction. The desired Ni single atomic catalysts achieve high generation activity of ∼ 2262 μmol/h with apparent quantum efficiency (A.Q.E.) of 0.20% for CO 2 -to-CO in 0.1 atm CO 2 pressure. No measurable H 2 is produced in the catalytic process, affording nearly 100% CO selectivity over water splitting. This superior activity and selectivity outperform most previous atomical catalysts. Mechanistic analyses elucidate that the highly dispersed Ni atoms act as active sites for effective CO 2 binding and activation, and stabilize the rate-determining step of intermediates for CO generation. This work discloses the relationship between catalytic properties and single atoms for efficient solar-driven diluted CO 2 reduction.
研究领域:
催化
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光催化
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材料科学
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化学工程
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环境科学
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2023
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IF 6.6
Liangchen Yue,Hao Guo,Junjie Hua,Miao Yu,Keliang Liu,Xian Yang,Jianzhong Liu,Jun Cheng
To develop a low-cost acidic water electrolysis catalyst with high efficiency and stability and low Ir content, a catalyst with highly dispersed Ir/Fe complex sites (∼ 5 wt% Ir) was synthesized by a simple carbonization and oxidation process. N-defective g-C 3 N 4 (N CN) was introduced to enhance the support effect between metal nanoparticles and CN bases and the intrinsic catalytic activity for the oxygen evolution reaction (OER). N CN provided more active sites and adjusted the electronic structure of CN. Compared with the original single Ir catalyst, the electrons of the Ir-Fe metal catalyst were transferred from the base to the metal, which maintained the high OER performance and stability of the catalyst. Density functional theory calculations demonstrated that the Gibbs free energy of Ir/Fe@N CN was greatly reduced during O*→OOH* as the rate-determining step. The overpotential of the Ir/Fe@N CN catalyst was 242 mV at 10 mA/cm 2 , and its mass activity (612.6 A/g) was much higher than that of IrO 2 (88.6 A/g), showing excellent OER performance. This study provides a new strategy for the design and optimization of highly efficient and low-cost acidic Ir/transition metal OER catalysts.
研究领域:
催化
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材料科学
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电化学
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能源材料
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2023
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IF 6.7
Menglin Li,Xinpeng Wang,Jian Zhang,Yonghao Gao,Wen Zhang
The capture of toxic radioiodine is an increasingly important priority for the safe development of nuclear energy. Copper is a promising alternative for expensive silver to capture iodine. To develop novel copper-based adsorbents and determine the effect of copper species on iodine adsorption, the metal–organic framework with dual-pyrazole ligands (MOF-303) is employed as the scaffold to bind Cu 2+ species. Cu 0 nanoparticles were formed after the reduction by NaBH 4 . The obtained Cu 2+ -MOF-303 and Cu 0 -MOF-303 show high iodine uptake capacities at 353 K, 747 mg·g −1 and 837 mg·g −1 , respectively. They also show high iodine uptake capacities of more than 300 mg·g −1 at a high temperature (423 K), which are better than other Cu-based adsorbents. Besides, the loading of Cu can enhance the iodine selectivity under humid vapor, and iodine adsorption rate in iodine-cyclohexane solutions. The Cu 0 on Cu 0 -MOF-303 can react with iodine directly via the redox mechanism. For Cu 2+ -MOF-303, the adjacent pyrazole ligands can chelate with Cu 2+ ions strongly and transfer charges to trapped iodine to form polyiodide anions, and thus stable CuI species could also be generated. The strategy of anchoring Cu species using MOF-303 provides large channels for iodine diffusion, and highly-dispersed Cu and N sites for iodine capture.
研究领域:
核能
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材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 149
·期 1
·180-189
·
IF 2.911
Hu Yin,Chen Wei,Ba Mingwei,Song Weiguo
Solvent-free selective hydrogenation of α -pinene to synthesize cis -pinane with high efficiency has always been a challenge in the catalytic research. The key to achieve this goal is the development of the highly efficient and recyclable catalysts. Cubic NaNbO 3 crystals were functionalized by (γ-aminopropyl)-triethoxysilane (APTS) and decorated with Ru species by a simple solvothermal approach combined with a sol-gel method. And this compound was applied to the catalytic hydrogenation of α -pinene. The crystal phase, chemical structure and surface components of the catalysts were analyzed by X-ray diffraction, field emission transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectra and thermogravimetric analysis. APTS-functionalization of the catalyst surface contributes to the highly dispersed and uniform Ru species with small particle size, leading to the outstanding conversion of α -pinene and selectivity of cis -pinane over NaNbO 3 /APTS/Ru catalyst. The performance of this catalyst is better than that of other similar catalysts, and is comparable to that of commercial Ru/C. The possible mechanisms of the formation of catalyst and the hydrogenation reaction were proposed and discussed. The decrease of catalytic performance after seven cycles should be ascribed to the decomposition and leaching of APTS during the hydrogenation process. The work provides an alternative strategy to design a kind of reusable catalyst with highly efficient hydrogenation performance based on the surface functionalization. Graphical Abstract
研究领域:
催化
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材料科学
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化学工程
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物理化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）