APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
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IF 24.319
Haolan Liu,Zhili Chang,Jie Fu,Zhaoyin Hou
Cu-based catalysts play pivotal role in many industrial processes, however, its application under high temperature is restricted due to the low Tammann temperature of Cu. Improving the stability and activity of Cu-based catalysts at high temperature is a challenge. In this work, a stable Cu/ZnO@SiO 2 catalyst was prepared, in which silicon was introduced into CuZn-BTC precursor via a steam-assisted hydrolysis method before calcination and reduction. Characterizations found that Cu/ZnO@SiO 2 catalyst prepared via above strategy possesses increased surface area, more exposed active sites and excellent stability for ethanol dehydrogenation than Cu/ZnO (prepared from CuZn-BTC without SiO 2 ). It was confirmed that the space-time yield of acetaldehyde reached 9.0 g-acetaldehyde/g-cat/h, and Cu/ZnO@SiO 2 could maintain its activity within 200 h at 350 °C due to the ZnO decorated Cu particles (Cu/ZnO) were encapsulated in the octahedral shaped SiO 2 hollow.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
NANO
·
2022
·
IF 1.438
Hong Zhao,Zhenghua Du,Diandian Liu,Yijian Lai,Tao Yang,Mingyan Wang,Yuesheng Ning,Fujun Yin,Binyuan Zhao
The design and construction of semiconductor–metal heterojunctions are being considered to be an effective way to overcome the limited visible-light absorption of semiconductors. Herein, a facile and scale approach is reported for the first time to synthesize Cu/ZnO heterojunctions by one-step galvanic replacement between Zn and cuprous solution reaction. Two kinds of morphologies Cu/ZnO heterojunctions could be obtained by changing cuprous salt anion such as Br − , Cl − and I − . A flower-like Cu/ZnO heterostructured is chosen as a representative to demonstrate the facility and enhanced photocatalytic performance toward Rhodamine B degradation under visible-light irradiation. Results showed flower-like Cu/ZnO heterojunctions have higher photocatalytic performance than the other two morphologies. The galvanic replacement growth mechanism of Cu/ZnO heterojunctions was also further investigated. It is found that Cu/ZnO heterojunctions formed from Zn and Cu 2 O at an acid solution and room condition. This work indicates that galvanic replacement reaction at room temperature is an excellent technique to grow Cu/ZnO heterojunctions and demonstrates that the hole and electron transfer between Cu and ZnO can efficiently enhance their photocatalytic performance. This general method can also be further explored to guide the design of metal/metal oxide heterostructured on other substrates, such as Zn, Ni and Cu foils.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
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IF 2.8
Ji Yaxiong,Lin Shuang,Xu Guihong,Chen Tianen,Gong Jianchao,Meng Fanbin,Wang Yuanhao
Abstract Catalytic conversion of CO 2 to methanol with H 2 from renewable energy has attracted increasing interest as a promising strategy for reducing excessive CO 2 emissions. However, the performance of reported various catalysts still suffers from low methanol yield with a passable CO 2 conversion. In this work, Cu–ZnO–La 2 O 3 interfaces are constructed with various La 2 O 3 mole ratio. Compared to Cu/ZnO, the optimized catalyst (i.e., Cu 0.6 Zn 0.2 La 0.4 ) exhibits a much higher mass-specific methanol formation rate (159.3 g MeOH /kg cat /h) at 240 °C and 3 MPa. A series of ex-situ and in-situ characterizations, such as X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N 2 O titration measurements, and in-situ diffuse reflectance Fourier transform infrared spectroscopy ( in-situ DRIFTS) study, are used to investigate its structure and mechanism study. The dispersion of Cu over Cu/ZnO/La 2 O 3 catalyst is significantly enhanced, forming more Cu–ZnO–La 2 O 3 interfaces. LaO x species favor CO 2 activation and generate more carbon intermediates species for CO 2 hydrogenation. Furthermore, more Cu + is bonded, which stabilizes the key intermediate, inhibits its desorption, and facilitates its further hydrogenation to methanol. This work is expected to offer an effective strategy to develop new catalysts with high performance for CO 2 hydrogenation to methanol. Graphical Abstract
研究领域:
催化化学
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能源化学
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材料科学
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DOI
高影响因子
JACS Au
·
2025
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IF 8.7
Xuan Bie,Yukun Pan,Xiaowei Wang,Shiyu Zhang,Jiahui Hu,Xiaoxiao Yang,Qinghai Li,Yanguo Zhang,Robert E. Przekop,Yayun Zhang,Hui Zhou
Gas sources rich in CO2 derived from biomass/waste gasification, anaerobic digestion, or industrial carbon capture often contain impurities such as H2S, H2O, and NH3, which can significantly hinder catalyst performance. Here, we show the role of NH3 on the reverse water–gas shift (RWGS) reaction over a commercial Cu/ZnO/Al2O3 catalyst, examining its effects on both the catalytic activity and the catalyst structure. We found that NH3 reversibly decreases CO2 conversion immediately by suppressing carbonate hydrogenation and CO desorption. This effect intensifies with an increase in NH3 concentration but decreases at higher temperatures. However, prolonged exposure (over 100 h) to RWGS conditions in the presence of 1.4% NH3 leads to near-total and irreversible deactivation of the Cu/ZnO/Al2O3 catalyst. Under NH3 exposure, the catalyst loses Cu+ sites on the surface, causing a spatial separation of Cu and ZnO. Finally, to address this challenge, we propose a novel strategy to mitigate NH3 inhibition by decomposing NH3 into N2 and H2.
研究领域:
化学工程
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催化科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2021
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IF 5.062
Tianqinji Qi,Weizuo Li,Hong Li,Ke Ji,Shaoyun Chen,Yongchun Zhang
Revealing the origin of the enhanced performance on yttria (Y 2 O 3 ) promoted Cu/ZnO based catalyst for methanol synthesis via CO 2 hydrogenation is still challenging. To shed light upon the promotion effect of Y 2 O 3 modifier on binary Cu/ZnO catalyst for CO 2 hydrogenation reaction, a ternary Cu/ZnO/Y 2 O 3 catalyst was synthesized via a citric acid coordination-assisted strategy. The developed Cu/ZnO/Y 2 O 3 catalyst exhibited a remarkably higher Weight-time yeild of methanol (236.8 g MeOH g cat −1 ∙ h − 1 ) and methanol selectivity (81.1%) in comparison to Cu/ZnO catalyst (159.6 g MeOH g cat −1 ∙ h − 1 and 73.9%, respectively). Various characterizations results have uncovered the enhanced catalytic activity of Cu/ZnO/Y 2 O 3 catalyst for methanol synthesis was associated with small size and highly dispersed Cu species and abundant surface adsorption sites as well as more Cu-ZnO interfaces with strong interaction. Moreover, the Cu/ZnO/Y 2 O 3 catalyst displayed a superior weight-time yield of methanol with a time-on-stream of 100 h in comparison with classic Cu/ZnO catalyst. We anticipate that this basic design strategy will provide a novel alternative to expand opportunities to explore scalable, cost-effective catalysts for industrial methanol synthesis.
研究领域:
化学工程
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催化科学
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Ning Liu,Na Lu,Kun Zhao,Pengxiao Liu,ZhuMei Sun,Jing Lu
The conversion of methane (CH 4 ) and carbon dioxide (CO 2 ) into high-value products under mild conditions is crucial for addressing the greenhouse effect and advancing C1 chemistry. In this study, Cu/ZnO catalysts were prepared through a one-step wet reduction process, and the catalytic conversion of CH 4 and CO 2 into acetic acid molecules (CH 3 COOH) was achieved via photon activation at ambient temperature. The yield of acetic acid was 411.6 μmol/Lg cat −1 h −1 with a selectivity of 89.5 % under optimal conditions (100 mWcm −2 light intensity, 25 ± 2 °C, 2 MPa pressure, and a 1:1 CH 4 :CO 2 volume ratio). Enhanced solubility of CH 4 in aqueous under increased pressure and temperature was observed to improve acetic acid production. Additionally, the catalytic mechanism involved surface chemisorption of CH 4 and CO 2 , facilitated by ZnO and Cu in the catalyst, leading to C-C coupling and subsequent acetic acid formation, driven by photogenerated electron-hole migration. This study provides a foundational understanding for the synthesis of value-added chemicals through CH 4 and CO 2 conversion via C-C coupling in mild environments.
研究领域:
环境科学
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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
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Chenxu Guo,Miao Li,Wenming Guo,Jiawei Xie,Hang Qin,Moyu Liao,Yi Zhang,Pengzhao Gao,Hanning Xiao
Methanol steam reforming (MSR) is considered as a promising approach to provide hydrogen for proton-exchange membrane fuel cells. However, it is challenging to develop effective and durable Cu-based catalysts. Herein, Cu-ZnO catalysts are prepared by facile quenching of ZnO in copper nitrate solution followed by reduction to obtain the desired metal loading and induce the doping of surface metal heteroatoms for producing more vacancies. Catalysts enriched with oxygen vacancies can efficiently activate H 2 O and rapidly transform C-containing intermediates, resulting in higher methanol conversion and lower CO selectivity. As a result, the quenched optimal catalyst achieves 100 % methanol conversion and 0.05 % CO selectivity at 280 ℃, exhibiting the excellent catalytic performance in MSR reaction. In practical applications, structured catalysts are more attractive for large-scale catalytic reactions owing to the low pressure drop and high utilization efficiency. Therefore, ZnO-Cu 3 catalyst is coated on cordierite honeycomb ceramics with 100 % methanol conversion and 0.04 % CO selectivity at 280 ℃. After 100 h of the reaction, the structured catalyst remains ∼ 92.3 % with CO selectivity varying from 0.02 to 0.06 %, demonstrating the good catalytic stability in the long-term experiment. In addition, the evolution of reactants and intermediates on the catalyst surface are briefly described by FTIR spectra. This study offers a novel and efficient approach to obtain highly active and durable catalysts with great potential for industrial-scale preparation and application.
研究领域:
催化化学
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能源材料科学
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燃料电池技术
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DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
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2017
·Vol. 122
·期 2
·1129-1143
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IF 1.264
Hou Miaomiao,Jiang Hong,Liu Yefei,Chen Rizhi
The work aims to investigate the role of initial water content in the glycerol hydrogenolysis to 1,2-propanediol over Cu–ZnO in depth by characterizing the fresh and spent catalysts in detail with ICP, XRD, XPS, EDS, HRTEM, N 2 sorption, N 2 O chemisorption, H 2 -TPD and NH 3 -TPD. The glycerol conversion and 1,2-propanediol selectivity gradually reduce simultaneously with increasing initial water content. At higher initial water content, more CuO are formed, bringing about a decrease in the 1,2-propanediol selectivity. The sizes of Cu and ZnO crystallites increase tremendously with increasing initial water content, lowering the active surface area and acidity. Furthermore, the surface Cu content reduces along with the increase of surface Zn content at higher initial water content. The two aspects make a decrease in the glycerol conversion. This work would aid the glycerol hydrogenolysis to 1,2-propanediol over Cu–ZnO with high catalytic efficiency.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Haitao Yan,Didi Li,Zhaocong Jiang,Haoyuan Gu,Mengyuan Zhu,Yi-Fan Han,Minghui Zhu
Cu-based catalysts have been extensively used in the methanol steam reforming (MSR) reaction owing to low cost and high efficiency. In this work, we investigated the promotional effect of Fe on the Cu/ZnO/Al 2 O 3 catalysts prepared by an incipient-wetness impregnation method using a series of (quasi) in situ characterization techniques. The form of the Fe species was found to strongly depend on the Fe content. Fe species are present as highly dispersed FeO x in small amount of Fe with improved the dispersion of Cu. As Fe content increases, Fe species gradually transition to CuFe alloy and eventually to Fe 3 O 4 particles, leading to a decrease in Cu dispersion. With the gradual increase in Fe content, the apparent activity shows a volcanic trend, with CuAl-0.1Fe showing highest activity, whereas the intrinsic activity gradually decreases. Compared with CuAl- x Fe, adding moderate Fe to Cu/ZnO/Al 2 O 3 promotes the dispersion of Cu and Zn, forming abundant Cu-ZnO x interfacial sites, which improves both apparent and intrinsic activities. The best catalytic performance was obtained with the CuZnAl-0.1Fe catalyst, achieving the highest H 2 production rate of 134.7 mmol g cat −1 h −1 at 200 °C. This study reveals the role of Fe in Cu-based catalysts for MSR and inspires the design of improved Cu-based catalysts.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
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IF 5.2
Yangxian Ou,Tao Zhang,Li Lv,Wenxiang Tang,Shengwei Tang
CO 2 hydrogenation is one of the reactions to realize effective utilization of CO 2 , while Cu-Zn based catalyst is widely adopted for CO 2 hydrogenation to value-added chemicals like methanol. However, this process is less efficient since the poor performance of catalyst due to its poor dispersion or sintering issue. In this study, three kinds of SiO 2 supports (SBA-15, MCM-41 and Nano-SiO 2 ) with different porous structure were conducted to load same amount of 5.0 wt% Cu-ZnO active component (the molar ratio of Cu/Zn is 2.0), which were further applied for CO 2 hydrogenation. All catalysts were characterized chemically, morphologically and structurally by different techniques such as XRD , BET, TEM , H 2 -TPR and CO 2 -TPD. The results showed that the structure of three catalysts was basically preserved and the surface aera kept stable after loading active component, while the active component had the best dispersion when SBA-15 was used as the support and space-time yield of methanol is about 705.6 g MeOH •kg Cu −1 •h −1 ,which is higher than that of Nano-SiO 2 -5% (532.9 g MeOH •kg Cu −1 •h −1 ) and MCM-41–5% (213.2 g MeOH •kg Cu −1 •h −1 ). Due to the confined effect of mesoporous channel structure provided by SBA-15 support, the Cu-Zn interaction could be significantly enhanced with increasement of medium and strong alkaline sites, further improving CO 2 activation ability. This work provides a useful strategy to improve the catalytic efficiency of classical Cu-Zn catalyst for the CO 2 hydrogenation process.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
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IF 8.1
Guiming Xie,Xingyang Bai,Yanrui Niu,Zhangjun Bai,Qingyuan Yang,Jian Liu,Zhou-jun Wang
ZIF-8 was employed as partial Zn source to prepare high-performance Cu/ZnO/Al 2 O 3 catalysts for methanol synthesis via carbon dioxide (CO 2 ) hydrogenation. Among the CuZnAl-x catalysts (x = 1, 0.75, 0.5, 0.25 and 0, denoting molar ratio of ZIF-8/(ZIF-8 + Zn(NO 3 ) 2 ·6H 2 O), the CuZnAl-0.5 catalyst possessed the highest space time yield of methanol ( STY MeOH ), which recorded 416.4 g MeOH kg cat −1 h −1 at 250 °C and 3.0 MPa. Using ZIF-8 as partial Zn source was found to increase the specific surface area, induce oxygen vacancies, intensify metal-oxide interactions and enrich medium basic sites, which may rationalize the excellent methanol synthesis activity of the CuZnAl-0.5 catalyst. Besides, the CuZnAl-0.5 catalyst showed good stability for 30 h of reaction. This work offers a unique route to fabricate catalysts with the aid of MOFs precursors and highlights the significance of oxygen vacancies in methanol synthesis catalysts.
研究领域:
化学工程
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催化材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Xiaoxia Zhang,Zhipeng Zhou,Junjie Liao,Liping Chang,Jiancheng Wang,Weiren Bao
The ultra-deep removal of thiophene from coke oven gas (COG) is critical for the conversion of COG to methane. Currently, Cu/ZnO/Al 2 O 3 is considered as a promising sorbent for thiophene removal; however, its desulfurization performance is currently unable to meet the requirements for industrial applications. Here, a zirconium modification strategy is proposed to overcome this problem, allowing zirconium loaded copper-based sorbents (Cu/ZnO/Al 2 O 3 /ZrO 2 ) with significantly improved thiophene removal performance and high activity to be obtained. Characterization results showed that zirconium improved both the dispersion of copper and the concentration of Lewis acid sites on the sorbent surface. A ZrO 2 concentration of 2 % resulted in stronger Cu-Zn interaction, and the dispersion of Cu on the surface of the sorbent reached its maximum value (49.20 %). Additionally, the Lewis acid strength was also maximized, which greatly improved the desulfurization activity and resulted in a breakthrough adsorption capacity of thiophene (Q b-thiophene ) of 36.24 mg/g, which was about 17 % higher than that of the unmodified Cu/ZnO/Al 2 O 3 sorbent. These results demonstrate that the sulfur capacity of the sorbent can be increased by increasing the number of acidic sites on its surface, paving the way for ultra-deep thiophene removal in industrial applications.
研究领域:
化学工程
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环境科学
✓ 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）