JOURNAL OF RARE EARTHS
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2017
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IF 2.429
Linying Du,Weiwei Wang,Han Yan,Xu Wang,Zhao Jin,Qisheng Song,Rui Si,Chunjiang Jia
Copper-ceria sheets catalysts with different loadings of copper (2 wt.%, 5 wt.% and 10 wt.%) supported on ceria nanosheets were synthesized via a deposition–precipitation (DP) method. The prepared catalysts were systematically characterized with various structural and textural detections including X-ray diffraction (XRD), Raman spectra , transmission electron microscopy (TEM), X-ray absorption fine structure (XAFS), and temperature-programmed reduction by hydrogen (H 2 -TPR), and tested for the CO oxidation reaction. Notably, the sample containing 5 wt.% of Cu exhibited the best catalytic performance as a result of the highest number of active CuO species on the catalyst surface. Further increase of copper content strongly affects the dispersion of copper and thus leads to the formation of less active bulk CuO phase, which was verified by XRD and H 2 -TPR analysis. Moreover, on the basis of in-situ diffuse reflectance infrared Fourier transform spectroscopy ( in-situ DRIFTS) results, the surface Cu + species, which are derived from the reduction of Cu 2+ , are likely to play a crucial role in the catalyzing CO oxidation. Consequently, the superior catalytic performance of the copper-ceria sheets is mainly attributed to the highly dispersed CuO x cluster rather than Cu-[O x ]-Ce structure, while the bulk CuO phase is adverse to the catalytic activity of CO oxidation.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2019
·Vol. 72
·期 6
·417-424
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IF 1.226
Changna Gan,Yunhao Wang,Chenliang Ye,Cuili Guo,Changna Gan,Yunhao Wang,Chenliang Ye,Cuili Guo
A series of CuZnAl catalysts derived from layered double hydroxide precursors with different Cu/Zn molar ratios were synthesised by a co-precipitation method for methyl acetate hydrogenation. The best catalytic performance was obtained when the Cu/Zn molar ratio reached 0.25 : 1. After fixing the Cu/Zn molar ratio at 0.25 : 1, the effect of aging methods, including ultrasound, high shear mixer stirring, and magnetic stirring, were investigated, which showed that 0.25CuZnAl-u and 0.25CuZnAl-h exhibited a higher conversion and selectivity than that of 0.25CuZnAl-m, especially under low reaction temperatures. The physicochemical properties of the CuZnAl catalysts were characterised by X-ray diffraction, inductively coupled plasma–atomic emission spectroscopy, N2 physisorption, N2O chemisorption, transmission electron microscopy, H2-temperature-programmed reduction, X-ray photoelectron spectroscopy, and H2-temperature-programmed desorption. It was found that compared with 0.25CuZnAl-m, 0.25CuZnAl-u and 0.25CuZnAl-h possessed a stronger interaction between Cu and the support, smaller copper particle size, and higher copper dispersion, which improved the catalytic performance.
研究领域:
化学工程
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催化材料科学
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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Jing Liu,Yinzhao Jia,Sen Wang,Jinchuan Fan,Wei Huang
The impact of nanomaterial morphology on the structures of catalysts has drawn intense interest. Based on previous work, we discovered that ZnO plays an essential role in the ethanol production . In this research, we discussed the impact of ZnO with different morphology (rod-like, granular-like and flower-like) on the performance of CuZnAl slurry catalysts for the ethanol production. The catalytic performance was evaluated at H 2 /CO = 2, 250 °C and 4.0 MPa, and the catalyst structures were tested by XPS, in situ DRIFT and so on. The results show that CuZnAl catalysts prepared with rod-like and granular-like ZnO show the better selectivity of methanol and DME, which is assigned to the highly dispersion of Cu species and more quantity of acidic sites, respectively. CuZnAl catalyst prepared with flower-like ZnO possesses the higher total alcohol selectivity (45.0%) and the highest ethanol proportions in total alcohol (50.0%). Flower-like ZnO that exposed more polar (002) facets results in more surface defect structures (oxygen vacancy, Zn (2-δ) ) and high ratio of Cu 0 /Cu + in this catalyst, all of which are related to the formation of ethanol.
研究领域:
催化化学
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纳米材料科学
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Qing Zhang,Didi Li,Zhaocong Jiang,Haoyuan Gu,Mengyuan Zhu,Shiqing Jin,Minghui Zhu
Acknowledged as an ideal method for in situ hydrogen generation, methanol steam reforming (MSR) requires high-performance catalysts to enhance production efficiency. Herein, we prepared a series of Zr-modified Cu-based catalysts by a coprecipitation method and conducted a systematic analysis of the impacts of structural variations on MSR performance. Extensive characterization reveals a strong dependence of the catalyst’s surface structure on Zr content. Introducing a moderate amount of Zr to the Cu/ZnO catalysts forms ZnZrO x solid solution and increases Cu dispersion, forming more Cu-ZnZrO x and Cu-ZnO interfacial sites with higher H 2 production rate. Further increases in Zr content enlarge Cu nanoparticles and multiply Cu-ZrO 2 interfacial sites. The optimal catalyst with a Zn/Zr molar ratio of 5, with the richest Cu-ZnO/Cu-ZnZrO x interfacial sites, achieves the highest H 2 production rate of 117.4 mmol H 2 g cat -1 h -1 at 200 °C, which is 1.3 times and 6.8 times higher than those of Cu/ZnO and Cu/ZrO 2 , respectively.
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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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Fanjing Wei,Weizhou Jiao,Bo Liu,Hao Qin,Guisheng Qi,Jing Guo,Zhiguo Yuan,Liping Chang,Junjie Liao,Ting Li
Cu-ZnO is a promising sorbent for the removal of thiophene. However, the aggregation and growth of copper grains during the heating reaction leads to the sintering deactivation of the sorbent. Although various strategies have been proposed to introduce supports to mitigate these defects, the impact of supports on the desulfurization performance of sorbent remains poorly understood. In this study, Cu-ZnO/Al 2 O 3 sorbents were synthesized with excellent performance by incorporating Al 2 O 3 (derived from Al(NO 3 ) 3 , γ-Al 2 O 3 and AlOOH as aluminum sources) using co-precipitation and fractional precipitation methods. The thiophene removal evaluation was conducted in a fixed bed reactor. The results indicates that the breakthrough adsorption capacity for thiophene ( Q b-thiophene ) of sorbent synthesized using γ-Al 2 O 3 and AlOOH is approximately 25 % higher than that of those synthesized with Al(NO 3 ) 3 . In comparison to Al(NO 3 ) 3 , γ-Al 2 O 3 and AlOOH exert less influence on the precipitation and crystallization processes of Cu 2+ and Zn 2+ . Sorbents synthesized with γ-Al 2 O 3 and AlOOH as aluminum sources demonstrate higher copper dispersion, larger specific surface area and smaller grain size, all of which significantly enhance the desulfurization activity of sorbent. Furthermore, the use of γ-Al 2 O 3 and AlOOH as aluminum sources contributes to an increase in ZnO and unsaturated Zn δ+ contents on sorbent surface. This improvement enhances hydrogen storage capacity and promotes hydrogen spillover at the Cu-ZnO interface; additionally, it facilitates both the adsorption activation of thiophene and the stable fixation of sulfur species. These findings provide an important theoretical basis for the design and large-scale application of efficient desulfurization sorbents.
研究领域:
化学工程
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材料科学
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环境科学
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无机化学
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产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2017
·
IF 4.292
Chen Zhang,Haiyan Yang,Peng Gao,He Zhu,Liangshu Zhong,Hui Wang,Wei Wei,Yuhan Sun
A series of Cu/ZnO/Al 2 O 3 catalysts with the total weight percentage of Cu and ZnO from 9.94 wt.% to 44.5 wt.% have been prepared by ammonia deposition −precipitation method and tested for methanol synthesis from CO 2 hydrogenation. A Cu/Zn/Al layered double hydroxides (LDHs) precursor can be formed in situ on the surface of microspherical Al 2 O 3 which acts as both support and sole source of Al 3+ cations. With increase of total Cu and ZnO loading, the dispersion of copper and reducibility of CuO decline continuously, while the exposed copper surface area increases gradually. In addition, the formation of LDHs results in a stronger both basicity and acid strength on the catalyst surface. It is found that the CO 2 conversion increases linearly with increase of the Cu and ZnO loading. The methanol selectivity for the catalyst with low total metal loading (9.94 wt.%) is much lower than those for other catalysts, though it increases with increasing loading, which can be mainly assigned to the much smaller Cu particle size (<5 nm) and the higher ratio of isolated CuO phase. Moreover, the Cu/ZnO/Al 2 O 3 catalyst with relatively high total metal loading (44.50 wt.%) still exhibits a considerable stable catalytic performance due to the formation of LDH structure.
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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环境化学
✓ 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）