JOURNAL OF SOLID STATE CHEMISTRY
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2020
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IF 2.726
Yafei Guo,Guodong Wang,Xi Yao,Bingqian Liu
Several NiO–CuO–CeO 2 catalysts were prepared via different methods and characterized by different techniques. Structure-activity relationships of the catalysts were demonstrated, and the effect of preparation methods on CO oxidation behaviors was illustrated. Catalytic results evidenced that the NiCuCe-CP and NiCuCe-SG catalysts prepared by co-precipitation and sol-gel methods exhibited better CO oxidation activities and kinetic performance, as evidenced by their lower T 50 values (102 °C and 100 °C) and apparent activation energies (48.80 and 59.28 kJ/mol) as well as higher reaction rates (3.84 and 3.45 μmol/g/s). The XRD and HRTEM results suggested that the active species showed uniform dispersion with minimum crystallite size in the desired catalysts. The XRD, XPS , H 2 -TPR and Raman analysis suggested the formation of Ce 1- x Cu x O 2- δ and Ce 1- x Ni x O 2- δ solid solutions, indicating that the co-precipitation and sol-gel methods reinforced the interactions amongst the ternary metal oxides . This would afford the catalysts more oxygen vacancies for boosted CO oxidation activity. The mechanism was then proposed with the dual synergetic effects in solid solutions for facilitated oxygen mobility and the amorphous active metal oxides for promoted CO chemisorption . The desired NiCuCe-CP and NiCuCe-SG catalysts show potential application for CO abatement in closed-loop air revitalization.
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
产品关联
DOI
高影响因子
ACS Applied Nano Materials
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2022
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IF 6.14
Sainan Cao,Bingjie Zou,Jingxia Yang,Jinjie Wang,Huangdi Feng
A heterogeneous catalyst CuO–CeO2 with a hollow structure was successfully synthesized by assembling CuO on the outer surface of CeO2 hollow spheres through a layer-by-layer deposition strategy. Further reduction under a H2 atmosphere was carried out to modify its surface state, resulting in sample r-CuO–CeO2. The catalysts were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). SEM and TEM showed that the synthesized catalysts had a hollow sphere structure, which can expose more active sites and promote mass transfer. The results of XPS revealed that the content of Cu0&Cu+ increased from 13.6 to 19.0% after H2 reduction, which was conducive to the activation of terminal alkyne to promote the annulation/A3-coupling reaction. The conversion of this cascade reaction with the r-CuO–CeO2 catalyst can reach more than 95%, while the value was only 55% by using CuO–CeO2 as a catalyst. Moreover, the r-CuO–CeO2 catalyst showed a good recycle property and group compatibility in the general applicability of the cascade annulation/A3-coupling reaction, providing a series of propargylamine derivatives in good chemoselectivity.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Lijian Wang,Yanqun Zhu,Hui Yang,Yong He,Jun Xia,Yanwei Zhang,Zhihua Wang
The effect of several catalyst supports with large specific surface area (such as SiC, Al 2 O 3 , SiC–Al 2 O 3 –ball, and SiC–Al 2 O 3 ) on catalytic activity was evaluated in this study. CuO–CeO 2 supported on SiC–Al 2 O 3 exhibited high stability and activity, which was considerably close to the thermodynamic equilibrium curve at 625 °C during the stability test for 50 h. The SO 3 decomposition temperature decreased from 750 °C to 625 °C. SiC–Al 2 O 3 contained numerous micropores and mesopores and had a large specific area, indicating strong adsorption, as determined by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption measurement. X-ray photoelectron spectroscopy (XPS) revealed that the surface of SiC–Al 2 O 3 consisted of Al 2 O 3 , SiC, and SiO 2 and that the cerium oxide surface had the largest number of defects. Temperature-programmed reduction (H 2 -TPR) results indicated that the cerium–copper oxides on the surface of powdered SiC–Al 2 O 3 had the strongest redox potential and that CuO had the lowest reduction temperature.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Yuchuan Ye,Jing Xu,Liangjun Gao,Shaohong Zang,Liqiao Chen,Luhui Wang,Liuye Mo
The impregnation method is one of the most popular methods for preparing various types of supported catalysts. However, the preparation of highly active catalysts by the conventional impregnation method is still a great challenge. In this paper, a modified impregnation method (MI) was developed to prepare CuO/CeO 2 catalysts for the catalytic oxidation of ethyl acetate (EA). It was found that the 5 %CuO/CeO 2 catalyst (5-MI-500) prepared by MI method achieves 100% EA conversion at a low temperature of 200 °C. However, the temperature for 100% EA conversion over the 5 %CuO/CeO 2 catalyst prepared by the conventional method is as high as 300 °C. Notably, the 5-MI-500 catalyst exhibits the highest proportion of well-dispersed CuO and Cu-O-Ce structures, which synergistically enhance catalyst activity. The well-dispersed CuO particles enhance the redox ability of the catalyst, while the Cu-O-Ce structure provides high activated oxygen via oxygen vacancy and better thermal stability during catalytic reaction. Accordingly, the possible reaction mechanism over the 5-MI-500 catalyst for EA oxidation was proposed. This study demonstrates that the MI method reported in this paper can provide a feasible methodology to prepare highly active catalysts with unique structures.
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 HYDROGEN ENERGY
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2020
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IF 4.939
Tuya Naren,Guojuan Jing,Lei Xue,Qi Wang,Yuansong Zhao,Caixia Li,Suhong Lu,Jinfang Wu,Shanghong Zeng
The development of superior catalysts for preferential oxidation of CO has always maintained challenging in heterogeneous catalysis . Herein it is found that the Pt 0.05 /CuO–CeO 2 catalyst exhibited high activity and selectivity for preferential oxidation of CO at working temperature of proton-exchange membrane fuel cells (~80 °C). The studies indicate that the presence of platinum and cerium promote the generation of oxygen vacancy and the dissociation of O 2 molecules. Meanwhile, the introduction of platinum facilitates the reduction of copper and cerium species as well as enhances the quantity of lattice oxygen. The timely update of lattice oxygen promotes CO oxidation with the help of oxygen vacancy. The finding may provide new ideas for developing the excellent ternary catalyst for preferential oxidation of CO at the proton-exchange membrane fuel cells working temperature.
研究领域:
催化
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材料科学
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燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2025
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IF 2.5
Lu Ji,Conghui Che,Fang Li,Wei Xue,Xiaoshu Ding,Dongsheng Zhang,Jing Li,Xinqiang Zhao,Yanji Wang
Methoxycarbonylation of aniline (AN) with dimethyl carbonate (DMC) to produce methyl N-phenylcarbamate (MPC), a key intermediate in non-phosgene diphenylmethane diisocyanate (MDI) synthesis, is facilitated using a newly developed CuO–CeO2 catalyst. This catalyst demonstrated a high AN conversion rate of 95.1% and an MPC selectivity of 92.7% at an nDMC/nAN ratio of 10. The catalyst's effectiveness is attributed to the synergistic interaction between CuO and CeO2, which enhances oxygen vacancy generation and increases the acid amount, as well as Lewis acid sites. Weak Lewis acid sites are conducive to MPC synthesis. There are three distinct copper species present in the CuO–CeO2 catalyst, among which the copper species doped into the CeO2 lattice is beneficial to MPC synthesis. The deactivation of the catalyst, due to the reduction of CuO by methanol, and catalyst regeneration through calcination are discussed. The catalytic mechanism is explored with in situ FT-IR, providing deeper insight into the methoxycarbonylation process.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
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