RENEWABLE ENERGY
·
2024
·
IF 9
Daxin Jiang,Min Lin,Yuhao Yan,Lulu Zhan,Rui Li,Yulong Wu
Catalytic hydrodeoxygenation (HDO) is an effective way to produce high–value products from lignin-derived phenolic compounds. In this work, three different morphologies of Ni/CeO 2 catalysts (amorphous, cubic, and rod-shaped) have been prepared through the conventional wet impregnation method. They can be used for the HDO of guaiacol to prepare cyclohexanol, an important chemical raw material. The influence of different morphologies of CeO 2 on catalytic activity was explored. The research results indicate that Ni/CeO 2 –r catalysts with rod-shaped structures exhibit excellent catalytic properties. As a result, a 100 % conversion rate and 96.9 % cyclohexanol yield were achieved on the Ni/CeO 2 –r catalyst at 240 °C. The catalytic performance of the three catalysts follows this order: Ni/CeO 2 –r (rod-shaped) > Ni/CeO 2 –c (cubic) > Ni/CeO 2 –p (amorphous). The results of Raman and XPS indicate significant differences in the surface oxygen vacancy in catalysts with different morphologies. The Ni/CeO 2 –r catalyst has the highest oxygen vacancy concentration and defect. In addition, Ni/CeO 2 –r also has the largest specific surface area (S BET ) and the highest nickel dispersion, and forms more Ni 0 because of the strong interaction of Ni species and CeO 2 support. Therefore, Ni/CeO 2 –r exhibits the most excellent catalytic performance for the hydrogenation of guaiacol than the other two catalysts. Moreover, the cycling activity test was also investigated over the Ni/CeO 2 –r catalyst. After five cycles, the conversion rate of guaiacol and the yield of cyclohexanol hardly decrease. This work provides vital ideas for the development of higher-activity, higher-stability, and low-cost catalysts for the conversion of lignin-derived phenolic compounds in the future.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yu Fan,Bowen Lu,Ziqiang Han,Cong Luo,Liqi Zhang
CeO 2 support inhibits CaO sintering, and oxygen vacancy influences CO 2 hydrogenation performance, making CeO 2 widely applied in Integrated CO 2 capture and in-situ conversion technology for reverse water–gas shift (ICCC-RWGS). Oxygen vacancy concentration was dependent on the morphology of CeO 2 , which would affect metal dispersion and CO 2 hydrogenation conversion. However, Very little is known about the morphology effect of CeO 2 on the carbon capture and in-situ hydrogenation performance of DFMs. Here, Cu/CeO 2 with different CeO 2 morphologies was synthesized, and high Cu dispersion was achieved on Cu/CeO 2 -R, exhibiting the best CO 2 hydrogenation performance. Integrated Cu/CeO 2 with CaO by physical mixing method, CaO-Cu/CeO 2 was used to investigate the morphology effects of CeO 2 on the performance of CaO-Cu/CeO 2 for integrated CO 2 capture and conversion to CO. CaO-Cu/CeO 2 -R exhibited the best capture-hydrogenation performance (CO 2 conversion rate of 75 %, CO production rate of 9.72 mmol/g). The CeO 2 -R provided more surface oxygen vacancies, enhancing carbonate hydrogenation. The larger specific surface area and {1 1 0} crystal plane of CeO 2 -rod enhanced Cu dispersion, and the smaller particle size of CeO 2 -R enhanced its interaction with CaO, improving the cyclic stability of CaO-Cu/CeO 2 -R. The hydrogenation performance of CaO-Cu/CeO 2 was dependent on the morphology of CeO 2 , providing insights into the design of high-activity metal catalytic components in ICCC-RWGS.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Horizons
·
2023
·Vol. 8
·期 6
·812-826
·
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
Polymers
·
2021
·Vol. 13
·期 2
·183
·
IF 4.329
Xiaoyan Liu,Handuo Jie,Ruidan Liu,Yanqi Liu,Tianyu Li,Kai Lyu
Due to its special two-dimensional lamellar structure, graphene possesses an excellent shielding effect, hydrophobic characteristics and large specific surface area, which can effectively isolate the internal structure from the external corrosive media. However, lamellar graphene is easy to stack and agglomerate, which limits its anti-corrosion performance. In this paper, cerium oxide-graphene oxide (CeO2-GO) nanocomposites were prepared by a hydrothermal synthesis method. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) were applied for microstructure examination, showing that a large number of nanoscale granular cerium oxide grew on the lamellar graphene oxide surface, which improved the dispersion performance of graphene inside the matrix. The anti-corrosion properties of the coating were analyzed and illustrated by open circuit potential (OCP), frequency response analysis, Tafel curve and Mott–Schottky curve. The results indicated that the CeO2-GO (4:1) nanocomposite not only eliminated the agglomeration of graphene to some extent, but also prepared the graphene epoxy coating with good dispersion, which further promoted its anti-corrosion performance. The paper proposed a feasible solution for GO dispersion in cement-based materials and lays a solid theoretical foundation for the engineering application of cerium oxide-graphene oxide modified anticorrosive coating.Keywords:CeO2;GO;CeO2-GO;dispersion;anti-corrosion performance
研究领域:
材料科学
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腐蚀与防护
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
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2018
·
IF 6.759
Houlin Wang,Shuting Luo,Meisheng Zhang,Wei Liu,Xiaodong Wu,Shuang Liu
Though the catalytic oxidation of CO, NO and soot over CeO 2 could be understood within a similar Mars-van Krevelen-type mechanism, these reactions were likely to be driven by different active phases. In this work, several CeO 2 and Ag/CeO 2 nanorods with different contents of surface oxygen vacancies (V O-s ) and active oxygen species (O x − ) were designed as model catalysts. Their catalytic performance indicated that, CO oxidation was determined by pre-existing ceria V O-s , while O x − participated in NO and soot oxidation directly. Besides, by loading silver onto the high-temperature aged CeO 2 nanorods, Ag/CeO 2 catalysts with high availability of ceria lattice oxygen were obtained, whose low-temperature oxidation activity was proven comparable to that of the platinum catalysts. In this sense, the model designing in this work not only provided methods to find out proper reactivity descriptors, but also conferred low-cost catalysts with high practical potential.
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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环境化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Ting Yi,Yibo Zhang,Xiangguang Yang
Pt@CeO 2 /MCM-56 (PCM) and CeO 2 -CuO (9:1)/MCM-56 (CCM) were combined to purify the exhaust emissions from diesel vehicles in three configuration statuses, defined as configuration A—where CCM stays above PCM, configuration B—where PCM stays above CCM, and configuration C—where CCM mixes with PCM homogeneously in loose contact. Among these combined catalysts, the configuration A is most favorable for the selective catalytic reduction (SCR) reaction, with >80% NO x conversion obtained at the temperature range of 150–550 °C and gas hourly space velocity (GHSV) of 240,000 ml g −1 h −1 . NH 3 -TPD, H 2- TPR and NH 3 conversion measurements demonstrated that NH 3 can be selectively used to reduce NO x in the configuration A but is over-oxidized if the reaction is operated in configuration B or configuration C status, deteriorating the deNO x activity at temperature above 250 °C. Hence, configuration A not only takes advantage but also overcomes the shortcomings of PCM and CCM, leading to high NO x conversion and N 2 selectivity. A significant decrease in the onset temperature of soot combustion was also observed in this research.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
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2014
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IF 4.835
Sujie Chang,Shigang Ruan,Erlong Wu,Weixin Huang
Oxide-on-metal particles with exposed interfaces exhibit wealthy structures and functions, but their facile synthesis remains as a challenge. Herein we report a facile O2-assisted hydrothermal method to synthesize CeO2-on-Ag particles with different CeO2 thicknesses. In this novel approach Ag particles catalyze the O2 + H2O reaction to form surface hydroxyls that induce the preferential nucleation of Ce(OH)3 on the surfaces of Ag particles, eventually forming CeO2 adlayers on Ag particles. CeO2-on-Ag particles exhibit the CeO2 thickness-dependent SERS effect in which their best SERS effect is 2 orders stronger than that of Ag particles. They also exhibit CeO2 thickness-dependent catalytic performance in CO oxidation in which the best one is as active as traditional CeO2-supported Ag catalyst. These results open up new opportunities to synthesize oxide-on-metal particles and explore their functions by tuning the oxide adlayer thickness.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jialin Wu,Xuan Liu,Rumeng Zhang,Jianbin Zhang,Huayan Si,Zhaojun Wu
A simultaneous titration-calcination strategy was proposed to synthesize core–shell type (CaCO 3 /Ce(OH)CO 3 )@Ce(OH)CO 3 precursors by titrating Ca 2+ and Ce 3+ into aqueous CO 2 storage material (CO 2 SM) solution simultaneously without adding any templating agents or surfactants. After calcination at 900 °C, the novel core–shell type (CaO/CeO 2 )@CeO 2 composite adsorbent with the strong stability of adsorption cycle was synthesized. The effects of Ca/Ce doping ratio, CO 2 SM dosage, drop rate and temperature conditions on the CO 2 adsorption performance on the composite adsorbent during the calcium cycle were investigated. The synthetic adsorbent with a Ca/Ce doping ratio of 24: 1 had the strongest CO 2 capture performance during the calcium cycle, and it mainly consisted of CaO and CeO 2 . The CO 2 adsorption amount still maintained at about 430 mg/g after 15 cycles under the adsorption–desorption conditions at 750 °C and 900 °C. (CaO/CeO 2 )@CeO 2 composite adsorbent is a core–shell structure with CeO 2 as the shell and CaO/CeO 2 as the liner, in which CeO 2 is uniformly dispersed in CaO pore channels, which gives the adsorbent a stable pore structure and enhances the anti-sintering performance of Ca-based adsorbent. Due to the special property of CeO 2 , it can also promote the ion migration during the carbonation process, thus maintaining the adsorption activity. Density functional theory (DFT) calculations successfully explain why CeO 2 can be used as an inert dopant to promote the adsorption of CO 2 . After that, the synthesis mechanism of core–shell adsorbent and the reaction mechanism of CO 2 adsorption are proposed in conjunction with the series characterization. This work provides a new strategy for the efficient synthesis of Ca-based adsorbents with special morphology and a new idea for CO 2 capture.
研究领域:
材料科学
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环境工程
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化学工程
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计算化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Zhongchun Yuan,Tingting Cao,Min Deng,Jun Ma,Shuo Geng,Chunliang Yang,Yuan Ren,Mengqin Yao,Fei Liu,Xiaodan Wang
It is very crucial but still a huge challenge to develop efficient and durable catalysts to promote hydrogen production from formic acid (FA). Herein, three CeO 2 with structurally well-defined different shapes, i.e., sCeO 2 (spheres), rCeO 2 (rod) and oCeO 2 (octahedral), are prepared, and their effect on the crystal faces and oxygen vacancy over the constructed heterostructure catalysts (Pd-CeO 2 /C) have been intensively investigated in the FA dehydrogenation. Pd-sCeO 2 /C outperforms the other catalysts with a turnover frequency (TOF) value of 2691 h −1 and selectivity to hydrogen of 100 % at 30 °C. A synergism between the CeO 2 (1 1 0) facet and more oxygen vacancies is considered to be key to obtaining the high reactivity. Moreover, biomass carbon promotes the dispersion of Pd-CeO 2 heterostructures due to its large specific surface area and causes more defects in the Pd-CeO 2 /C. Combined with in-situ FTIR and density functional theory (DFT), it is speculated that FA is decomposed through formate pathway over the Pd-sCeO 2 /C. This work thus provides a reasonable design and controllable synthesis strategy for the effective application of FA as an available liquid phase hydrogen storage material.
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
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 4
·1007-1016
·
IF 2.372
Liu Pengcheng,Niu Ruyue,Li Wei,Wang Shuang,Li Jinping
Three Ru/CeO 2 catalysts with different morphologies of CeO 2 (cube spheres, microspheres and nano rods) were used to evaluate the support-morphology-dependent ammonia synthesis activity. Catalytic experiments show that the Ru/CeO 2 –CS catalyst has higher catalytic activity (27,000 µmol g −1 h −1 ) than Ru/CeO 2 –MS (21,000 µmol g −1 h −1 ) and Ru/CeO 2 –NR (15,000 µmol g −1 h −1 ) under the reaction conditions of 450 °C, 3 MPa, H 2 /N 2 = 3:1 (60 mL min −1 ). The transmission electron microscopy analysis showed that the dispersion of active metal Ru is affected by the morphology of CeO 2 . Brunauer–Emmett–Teller indicates that the 3–5 nm the pore size of CeO 2 supports contributes to the active metal Ru enters the pores of the CeO 2 support, which improves the dispersion of Ru and prevents the sintering and agglomeration of Ru in some extent. TPR studies shown that the reduction of ruthenium oxide is influenced by the morphology of CeO 2 . XPS and CO 2 -TPD demonstrated that the Ru/CeO 2 –CS catalyst exhibited higher surface oxygen vacancies, higher basic site density and lower Ru binding energy, indicating that Ru nanoparticles in Ru/CeO 2 –CS is more electron-rich and are more capable of back-donating electrons to adsorbed N 2 and subsequently activate N 2 . Our results indicate that the morphology effect of the CeO 2 supports on the Ru/CeO 2 catalyst is related to the pore size distribution and the surface oxygen vacancies of the CeO 2 supports, ratio of Ru n+ , basic site density. Graphical Abstract
The CeO 2 –CS (cube spheres) morphology facilitated the dispersion of the active metal Ru and the 3 nm the pore size of CeO 2 –CS contributed to the Ru enters the pores of the support. And the Ru/CeO 2 –CS catalyst exhibited higher surface oxygen vacancies and lower Ru binding energy, which enhanced the adsorption of hydrogen and nitrogen species and thus weakened the N≡N bond.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 3
·288
·
IF 3.444
Feihu Liu,Zhong Wang,Da Wang,Dan Chen,Fushan Chen,Xuebing Li
The CeO2ordinary amorphous, nanopolyhedrons, nanorods, and nanocubes were prefabricated by the hydrothermal method, and employed as carriers of Fe/W–CeO2catalysts to selectively catalyze the reduction of NO with ammonia. Characterization results indicated that the morphology of CeO2support originated from selectively exposing different crystal surfaces, which has a significant effect on oxygen vacancies, acid sites and the dispersion of Fe2O3. The CeO2nanopolyhedrons catalyst (Fe/W–CeO2–P) showed most oxygen vacancies, the largest the quantity of acid sites, the largest BET (Brunauer-Emmett-Teller) surface area and the best dispersion of Fe2O3, which was associated with predominately exposing CeO2(111) planes. Consequently, the Fe/W–CeO2–P catalyst has the highest NO conversion rate in the temperature range of 100–325 °C among the ordinary amorphous, nanorods, and nanocubes Fe/W–CeO2catalysts.Keywords:morphology;Fe/W–CeO2;nanopolyhedra;CeO2(111) planes
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2022
·Vol. 128
·期 7
·1-9
·
IF 2.983
Zhang Lei,Han Zhikun,Jia Yang,Han Yuzhen
Nitrogen oxides (NOx) could cause acid rain, photochemical smog, and even cause serious harm to human life and health and safety. Therefore, it was urgent to control and reduce NOx. In this paper, CeO 2 with a spherical structure was prepared by hydrothermal method, and the influence of different preparation conditions on the formation of CeO 2 was studied by orthogonal experiments. Then CeO 2 was used as the carrier, and a MnO 2 @CeO 2 core–shell catalyst with MnO 2 as the core and CeO 2 as the shell was developed. And it was successfully applied to SCO denitration. Through SEM, TEM and XRD characterization, the effects of different manganese-cerium ratios and core–shell morphology on the denitration performance were studied. The results showed that: (1) When the concentration of cerium chloride solution was 0.6 mol/L, urea was 30 g, glucose was 40 g, and the hydrothermal temperature is 200 ℃, the prepared CeO 2 catalyst had uniform particle size and high dispersibility. Its catalytic activity was better than that of catalysts prepared under other conditions, and the conversion rate of NO at 250 ℃ was up to 85%; (2) The denitration performance of the MnO 2 @CeO 2 composite3 catalyst was significantly better than that of the CeO 2 catalyst alone. At the same time, the MnO 2 @CeO 2 core–shell catalyst prepared with MnCl 2 ·4H 2 O as the manganese precursor had a better conversion rate of NO than that of the other two manganese precursor catalysts.
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）