RSC Advances
·
2021
·Vol. 11
·期 34
·21057-21065
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IF 3.361
Dongren Cai,Bin Chen,Zhongliang Huang,Xiaoli Zeng,Jingran Xiao,Shu-Feng Zhou,Guowu Zhan
Herein, a series of metal oxide/CeO2 (M/CeO2) nanocomposites derived from Ce-benzene tricarboxylate (Ce-BTC) adsorbing with different metal acetylacetonate complexes were prepared for CO oxidation under four different CO gas atmospheres. It was demonstrated that Cu/CeO2 exhibited the highest catalytic activity and stability in CO oxidation. Remarkably, both O2 selectivity and CO selectivity to CO2 are 100% in most of the investigated conditions. Several analytical tools such as N2 adsorption–desorption and powder X-ray diffraction, were employed to characterize the prepared catalysts. In addition, the excellent catalytic performance of Cu/CeO2 in CO oxidation was revealed by H2 temperature-program reduction experiment, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy. The result showed that high oxygen vacancy and high CO adsorption capacity (Cu+–CO) caused by the electron exchanges of Cu2+/Cu+ and Ce3+/Ce4+ pairs (Ce4+ + Cu+ ⇆ Ce3+ + Cu2+) are two key factors contributing to the high oxidation performance of Cu/CeO2 catalyst.
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
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Bowen Lu,Tai Zhang,Liqi Zhang,Yongqing Xu,Zewu Zhang,Fan Wu,Xiaoshan Li,Cong Luo
CeO 2 -based catalysts have been widely used in the CO 2 hydrogenation process. The oxygen vacancies on CeO 2 resulted from Na ion incorporation play a vital role in CO 2 conversion activity, the effect of Na + ion-doped in CeO 2 during CO 2 hydrogenation was rarely studied. In this work, the LN-CeO 2 catalysts with different n NaOH :n Ce ratios were prepared with liquid nitrogen(Liquid Nitrogen-CeO 2 , LN-CeO 2 ), and the effect of the n NaOH :n Ce ratio on the microstructure of the LN-CeO 2 catalysts were evaluated. The best CO 2 hydrogenation performance was achieved by LN-CeO 2 -100 with a CO production rate of 3.90 mol/g cat· h at 800 °C (100% CO selectivity). The kinetic results indicated that the CO 2 hydrogenation performance difference among these LN-CeO 2 catalysts resulted from the CO 2 activation process. Oxygen vacancies could enhance CO 2 activation on the surface of LN-CeO 2 , and oxygen vacancies displayed a linear correlation relationship with the Na content doped in LN-CeO 2 . The highest concentration of oxygen vacancies resulted from Na ion incorporated and lower CO 2 reaction order was closely related to CO 2 hydrogenation performance of LN-CeO 2 -100. These results will give insight into the Na effect on the CO 2 hydrogenation mechanism over CeO 2 .
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
Nanoscale Horizons
·
2023
·Vol. 8
·期 6
·812-826
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IF 9.7
Junqing Ye,Meizan Jing,Yu Liang,Wenjin Li,Wanting Zhao,Jianying Huang,Yuekun Lai,Weiyu Song,Jian Liu,Jian Sun
Exploring eco-friendly and cost-effective strategies for structure engineering at the nanoscale is important for boosting heterogeneous catalysis but still under a long-standing challenge. Herein, multifunctional polyphenol tannic acid, a low-cost natural biomass containing catechol and galloyl species, was employed as a green reducing agent, chelating agent, and stabilizer to prepare Au nanoparticles, which were dispersed on different-shaped CeO2 supports (e.g., rod, flower, cube, and octahedral). Systematic characterizations revealed that Au/CeO2-rod had the highest oxygen vacancy density and Ce(III) proportion, favoring the dispersion and stabilization of the metal active sites. Using isopropanol as a hydrogen-transfer reagent, deep insights into the structure–activity relationship of the Au/CeO2 catalysts with various morphologies of CeO2 in the catalytic nitrobenzene transfer hydrogenation reaction were gained. Notably, the catalytic performance followed the order: Au/CeO2-rod (110), (100), (111) > Au/CeO2-flower (100), (111) > Au/CeO2-cube (100) > Au/CeO2-octa (111). Au/CeO2-rod displayed the highest conversion of 100% nitrobenzene and excellent stability under optimal conditions. Moreover, DFT calculations indicated that nitrobenzene molecules had a suitable adsorption energy and better isopropanol dehydrogenation capacity on the Au/CeO2 (110) surface. A reaction pathway and the synergistic catalytic mechanism for catalytic nitrobenzene transfer hydrogenation are proposed based on the results. This work demonstrates that CeO2 structure engineering is an efficient strategy for fabricating advanced and environmentally benign materials for nitrobenzene hydrogenation.
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
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
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
GREEN CHEMISTRY
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2023
·Vol. 25
·期 13
·5150-5159
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IF 9.8
Yuzhen Hu,Yanbin Cui,Shuoxiao Zhao,Xuelai Zhao,Xiaohong Hu,Zhenlong Song,Wei Fan,Qi Zhang
Selective cleavage of C–C bonds in the lignin structure is crucial for the depolymerization of lignin and producing value-added chemicals. In this study, we reported that Pd/CeO2 catalysts can selectively catalyze the Cα–Cβ bond cleavage of oxidized lignin model components and authentic lignin in an aqueous phase under mild conditions (50 °C, ambient pressure). A variety of β-O-4 and β-1 ketones with representative Cα–Cβ bonds were successfully cleaved yielding aromatic acids and phenols in 76.8–94.9% yields. Their unique catalytic properties are derived from the electron transfer between Pd and CeO2 support which facilitates active Pd2+ sites and reactive oxygen species formation. A mechanistic study elucidates that base-mediated C–H bond activation via enolization and in situ reactive oxygen species (˙O2−) formation are the key steps for the selective Cα–Cβ cleavage. Furthermore, the applicability of the system for the bond cleavage in an authentic lignin sample was demonstrated. Nearly 54.2 wt% of oxidized bamboo lignin was converted, generating aromatic monomer yields up to 35.9 wt%, with a high selectivity for aromatic aldehydes.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Jingheng Gao,Yifei Xiong,Qian Zhang,Yiwen Jiang,Jing Wang,Sibei Zou,Mingli Fu,Junliang Wu,Yun Hu,Daiqi Ye
MnO x -CeO 2 composite catalysts have attracted interest from all over the world as promising catalysts for carbon black oxidation. The contact between carbon black and catalyst, and the surface physicochemical properties of the catalyst, are the main factors in carbon black oxidation, while the contact is a basic one affecting the ignition of the oxidation. In this work, MnO x -CeO 2 catalysts with different geometric morphologies (nanorod and nanoparticle) are prepared to determine the effect of geometric morphology on the contact probability between catalysts and carbon black. Compared with the nanorod catalyst, nanoparticle catalyst is significantly advanced in catalytic activity (T 10 = 314 °C, T 50 = 346 °C, T 90 = 383 °C) and relative contact probability (9.549, compared to the 7.639 of nanorod catalyst, according to the 3D geometric modeling). O 2 -TPD, H 2 -TPR, and In-situ UV Raman experiments reveal that the concentration of surface intrinsic oxygen vacancy of the two catalysts are approximative. The consumption of oxygen vacancy is based on the active sites provided, which is relative to the morphology. The better consumption results in better utilization of intrinsic active oxygen species in nanoparticle sample. This finding proves the correlation between contact probability and carbon black catalytic activity, and witnesses that the consumption efficiency of surface intrinsic oxygen vacancy is an initial factor in carbon black oxidation.
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
FUEL
·
2021
·
IF 6.609
Xincheng Cao,Feng Long,Qiaolong Zhai,Jiaping Zhao,Junming Xu,Jianchun Jiang
To develop an efficient Ni-based catalyst for converting renewable fatty acids into high value-added fatty alcohols under mild reaction conditions, the scope of metal oxide modified nickel catalysts was scrutinized. The results show that MoO x modified Ni/CeO 2 catalyst exhibits the excellent catalytic performance in the conversion of fatty acids to form corresponding alcohols at mild reaction conditions (235 °C, 3.0 MPa H 2 ). Using stearic acid as a model substrate, Ni-MoO x /CeO 2 catalyst shows the 98.0% conversion and 96.2% selectivity to stearyl alcohol, which is significantly higher than that of Ni/CeO 2 catalyst and of a physical mixture of both Ni/CeO 2 and MoO x /CeO 2 . Detailed characterization (XRD, Raman, XPS, in situ CO-FTIR, HRTEM, and EPR) indicates that NiMoO 4 is the mainly active phase in the pre-reduced bimetallic catalysts. After reduction at 500 °C in a H 2 flow, the surface of Ni metal is decorated by the MoO x species, the phenomenon is similar to the strong metal-support interaction (SMSI) previously observed on reducible oxides. The presence of MoO x species in the bimetallic Ni-MoO x /CeO 2 catalyst not only improves the dispersion of metallic Ni, but also promotes the charge transfer from Ni to Mo. The electronic interaction at the interface of Ni and MoO x provides synergistic catalysis sites of electron-deficient Ni and MoO x species, which is primarily responsible for the excellent catalytic performance of the bimetallic Ni-MoO x catalyst. Additionally, the introduction of Mo species provides much oxygen vacancy sites for the adsorption of fatty acids, which results in high activity for the conversion of fatty acids. The insights into the synergistic catalysis between Ni and MoO x will provide new possibilities in the design of efficient Ni-based catalysts for selective hydrogenation of other biomass-derived compounds containing carboxylic group.
研究领域:
催化化学
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可再生资源转化
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材料科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Mingzhen Huang,Jinxin He,Kaiji Xu,Dongren Cai,Guowu Zhan
The supported Pt/CeO 2 catalysts are widely used for the catalytic oxidation of CO at ambient conditions. Herein, we reported a new strategy for modifying the interaction between Pt and CeO 2 support via pulsed steam treatment, which significantly optimized the catalytic performance of Pt/CeO 2 for CO oxidation. Specifically, the hollow CeO 2 nanospheres were prepared by using carbon spheres as sacrificial templates and then subjected to pulsed steam treatment at 150 °C for different times to obtain the CeO 2 -xH support (x means the time of pulsed steam treatment, min). It was found that the complete oxidation of CO can be achieved at 90 °C over the Pt/CeO 2 –50H sample, which was much lower than that (130 °C) on Pt/CeO 2 without pulsed steam treatment. The XPS and in-situ DRIFTS characterizations were conducted to reveal the high performance of the Pt/CeO 2 –50H catalyst for CO oxidation. It was found that the valence state of Pt significantly controlled by pulsed steam treatment was critical to the catalytic activity, whereby the presence of two types of active sites (Pt 0 -CO and Pt δ+ -CO) over Pt/CeO 2 –50H greatly promoted the combination of adsorbed CO and O 2 to generate CO 2 . Accordingly, this study provides a facile method to regulate the Pt valence state by pulsed steam treatment for CeO 2 support, which is critical to the CO oxidation activity.
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
Molecular Catalysis
·
2024
·
IF 3.9
Dongyang Yang,Bingxiao Feng,Hongxin Wang,Qingjuan Xie,Yaping Liu,Hengjun Gai,Hongbing Song
Selective oxidation of alcohols to aldehydes by molecular oxygen is one of the most important transformations in multiphase catalysis. In this paper, a catalyst with selective oxidation ability was designed and synthesized for the selective catalytic oxidation of benzyl alcohol. N-doped carbon materials were prepared by high-temperature calcination using hydrothermal reaction products of citric acid and melamine as a carbon source, and a bimetallic catalyst supported by Ru-CeO 2 was constructed using the mixture as the carrier for the selective oxidation of benzyl alcohol to benzaldehyde. The results showed that the introduction of CeO 2 could effectively improve the oxidizing ability and catalytic activity of the catalyst. The Ru-Ce 0.05 /NC170–600 catalyst was able to convert 85.5 % benzyl alcohol into benzaldehyde at 140 °C, 6 h, and 2 MPa, and the selectivity for benzaldehyde was 100 %. It was demonstrated by DFT that it was theoretically feasible to generate benzaldehyde by extracting hydrogen atoms from benzyl alcohol molecules. Further, the selective oxidation experiments on other alcohols showed that the catalyst has high activity for the oxidation of various alcohols to generate the corresponding carbonyl products, and it is a catalyst with broad-spectrum selective oxidation ability. In this study, a green synthesis route of benzaldehyde was proposed to solve the problems in the traditional process. Meanwhile, it provides a new idea for the synthesis of carbonyl products by selective oxidation of alcohols.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2015
·
IF 3.368
Xiaole Weng,Xiaoxia Dai,Qingshan Zeng,Yue Liu,Zhongbiao Wu
Heteropoly acids (HPAs) have been effectively utilized in selective catalytic reduction (SCR) of NO to improve the NH 3 absorption capacity and alkaline/alkali metal resistance for SCR catalysts. However, despite the promise on super-acidities, their other properties that would work on SCR process are still lack of exploration. In this study, a 12-tungstaphosphoric acid (H 3 PW 12 O 40 , HPW) was selected to modify a well-reported CeO 2 catalyst. The resulted CeO 2 /HPW catalyst was subsequently utilized for SCR of NO with excess NH 3 , which revealed a significantly promoted performance in SCR reaction. DRIFT analyses showed that the unique NO 2 absorption capacity of HPW could prevent the NO 2 being further oxidized into nitrate species and the abundant Brønsted acid sites could effectively retain the NH 3 , avoiding them being over-oxidized at evaluated temperatures. The presence of NO 2 was demonstrated able to induce a so called “fast SCR” reaction over the CeO 2 /HPW catalyst, which effectively facilitated the SCR reaction. Furthermore, we have also constructed a CeO 2 @HPW catalyst, which showed an enhanced SO 2 poisoning resistance in SCR reaction.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
PubMed
高影响因子
Progress in Natural Science-Materials International
·
2017
·
IF 2.038
Hongbin Dai,Yujie Zhong,Ping Wang
The synthesis of highly active and selective catalysts is the central issue in the development of hydrous hydrazine (N 2 H 4 ·H 2 O) as a viable hydrogen carrier. Herein, we report the synthesis of bimetallic Ni-Ir nanocatalyts supported on CeO 2 using a one-pot coprecipitation method. A combination of XRD, HRTEM and XPS analyses indicate that the Ni-Ir/CeO 2 catalyst is composed of tiny Ni-Ir alloy nanoparticles with an average size of around 4 nm and crystalline CeO 2 matrix. The Ni-Ir/CeO 2 catalyst exhibits high catalytic activity and excellent selectivity towards hydrogen generation from N 2 H 4 ·H 2 O at mild temperatures. Furthermore, in contrast to previously reported Ni-Pt catalysts, the Ni-Ir/CeO 2 catalyst shows an alleviated requirement on alkali promoter to achieve its optimal catalytic performance.
研究领域:
催化化学
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材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Pijun Gong,De Fang,Feng He,Junlin Xie,Haitao Wu
Cake-like MnO 2 @CeO 2 catalyst with hierarchical nanosheets structure has been successfully constructed by in situ methods. The relationship between structure and activity of the MnO 2 @CeO 2 catalyst was characterized using various analytical techniques. It is identified that rich surface oxygen species and better reducibility were generated due to the strong synergistic effect between MnO 2 and CeO 2 , and hence nearly T 90 toluene conversion can be obtained for the 10%-MnO 2 @CeO 2 catalyst under 240–300 °C. In addition, it is found that after loading MnO 2 on the multi-layer CeO 2 support to form a hierarchical cake-like structure, the oxygen vacancies, Ce 3+ /Ce 4+ and BET surface area of MnO 2 @CeO 2 increased significantly, which is beneficial to toluene adsorption and reaction. Furthermore, the in situ DRIFTS study demonstrated that the lattice oxygen and surface oxygen both participate in the toluene oxidation , whereas surface active oxygens adsorbed on the oxygen vacancies will lead to deep oxidation by forming abundance intermediates.
研究领域:
催化化学
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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）