FUEL
·
2023
·
IF 7.4
Zhihan Wu,Kuan Ding,Guiying Lin,Hongqi Sun,Shu Zhang
Ketonization of oxygenated compounds in pyrolytic products of biomass is an effective means for deoxygenation and upgrading of bio-oils. However, the ketonization potential of biomass-derived sugars and the mechanism underneath remain unclear. On this basis, a series of Fe doped CeO 2 catalysts were synthesized and employed for catalytic ketonization of xylan. Characterization of the catalysts proved the successful formation of the Fe-CeO x solid solution. Doping an appropriate amount of Fe (20–33%) ions on CeO 2 could obviously increase the number of oxygen vacancy and basic sites by up to 56.31% and 29.6%, respectively. During the catalytic reaction of xylan, pure CeO 2 exhibited a good ketonization ability during xylan pyrolysis, and the introduction of a certain amount of Fe further enhanced the ability. The highest yield of ketones was obtained by 33%Fe-CeO 2 , which was 38% higher than pure CeO 2 . The selectivity to linear ketones (acetone and 2-butanone) reached a maximum of 85% for 57%Fe-CeO x . Thus, oxygen-rich compounds had been converted to low oxygen containing and high-quality ketone components. Introducing Fe into CeO 2 favored the production of ethylene glycol rather than 2,3-dihydroxy propanal, and thus promoted the yield of acetone. This investigation provides fundamentals for the deoxygenation of biomass through catalytic ketonization, aiming at the production of value-added ketone products.
研究领域:
催化
·
化学工程
·
可再生能源
·
生物质转化
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhen-Yu Zhang,Tao Xie
Solar-driven photo-thermal dry reforming of methane (DRM) is an environmentally friendly production route for high-value-added chemicals. However, the lack of thorough understanding of the mechanism for photo-thermal reaction has limited its further development. Here, we systematically investigated the mechanism of photo-thermal DRM reaction with the representative of Ru/CeO 2 catalyst. Through in situ DRIFTs and transient experiments, comprehensive investigation into the reaction steps and their reactive sites in the process of DRM reaction were conducted. Besides, the excitation and migration direction of photo-electron was determined by ISI-XPS experiments, and the change of surface defect structure induced by light was characterized by ISI-EPR experiments. Based on the above results, the photo-enhancement effect on each micro-reaction step was determined. This study provides a theoretical basis for the industrialization of photo-thermal DRM reaction and its development of catalysts.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Lianbo Wang,Shilong Xing,Zizhen Shen,Huabing Liu,Chuanhai Jiang,Vincent Ji,Yuantao Zhao
In current work, Ni-Ti-CeO 2 nanocomposite coatings were achieved by co-adding Ti microparticles and CeO 2 nanoparticles. Designed experiments and COMSOL computer simulation were applied to reveal the synergistic role of Ti microparticles and CeO 2 nanoparticles in tailoring the spatial microstructures and properties of Ni-Ti-CeO 2 nanocomposite coating. Unilaterally, the conductive Ti microparticles conducted the growth behavior of Ni grains by current density concentration, distorting electronic field lines and heterogeneous nucleation. Individual domains consisting of inner nanograins and outer radial columnar grains surrounded Ti microparticles, where Ti microparticles acted as seeds. Ti microparticles tended to be aggregated, leading to spatial heterogeneity of microstructures. Ni deposits buried the Ti microparticles in forms of “covering model”, contributing to the formation of inside voids and rough surface and aggregation of Ti microparticles; on the other hand, the non-conductive CeO 2 microparticles hardly changed the distribution of current density and electronic field lines on the cathode surface. Ni deposits buried the CeO 2 microparticle in forms of “stacking model”, avoiding the inside voids and aggregation of particles. The incorporation of CeO 2 microparticle brought in microstructure evolutions only on its top side without disturbing the growth behavior of Ni grains on its lateral side or bottom, suggesting the limited effects. This was correlated with the presence of current concentration above the CeO 2 microparticle at the last stage of burying CeO 2 microparticle. The co-addition of Ti microparticles and CeO 2 nanoparticles into Ni deposits exploited the complementary action of the two particles, which gave birth to satisfied spatial microstructures and improved hardness. Ti microparticles took major responsibility for microstructure evolutions, while the CeO 2 nanoparticles were mainly in charge of the microstructure homogeneity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Congcong Shi,Huanhuan Zhang,Jiajia Jia,Xin Xing,Ting Li,Yujuan Zhang,Shengmao Zhang
Nano additives exhibit efficient anti-wear and friction reducing properties for various friction materials, thus having broad application prospects in engine oil. The synergistic mechanism between friction modifiers and nano additives is a key issue in the development of energy-saving engine oil. In this paper, the tribological properties of oleylamine (OM) modified CeO 2 nanoparticles and commercial organic friction modifiers glyceryl monooleate (GMO), glycol oleate (T403B), benzotriazole aliphatic amine (T406E) and molybdenum dithiocarbamate (MoDTC) in PAO/DLC solid-liquid composite lubricating system were investigated. It was found that only when CeO 2 nanoparticles were combined with GMO, the anti-wear and friction reduction performance of the system was better than that of nano additives, any friction modifiers, and their combination additives. The synergistic effect was demonstrated in the boundary lubrication range under reciprocating sliding conditions and fully lubricated range in the S-curve experiment under rotating sliding mode. Three-dimensional topography, EDS typical element distribution, and Raman analysis were performed on the worn surface, and the adsorption behavior of additives on metal and DLC surfaces was studied using quartz crystal microbalance (QCM-D). It was found that only lubricated with CeO 2 + GMO, a viscoelastic composite adsorption layer with both high adsorption quality and high adsorption layer density could be formed on the metal and DLC surfaces simultaneously. The adsorption layer has excellent tribological properties of high load-bearing capacity and low friction, which not only overcomes the high friction problem of CeO 2 nanoparticle solid tribofilm, but also avoids the high wear defect of tribofilm formed by friction modifier.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Shaodan Xu,Huanxuan Li,Jia Du,Junhong Tang,Liang Wang
We report the synthesis of subnanometric Au clusters with average diameters at 1.2 nm on a low-crystallinity CeO2 support (sub-Au/LC-CeO2), which exhibit high activities and selectivities in the aerobic oxidation of C–H bonds on a series of petroleum-derived hydrocarbons under solvent-free conditions. This phenomenon is strongly related to the maximized strong metal–support interactions between subnanometric Au and the LC-CeO2 support.
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
ENERGY & FUELS
·
2024
·
IF 5.2
Yanbin Zhang,Xifei Yin,Chenghu Zhang,Ying Li,Yinghui Sun,Jie Bai
Dry reforming of methane (DRM) provides an effective method for converting the two main greenhouse gases to hydrogen and carbon monoxide. In this work, Co-CeO2 and CoM-CeO2 (M = Ru, Pd, Pt) catalysts prepared by electrospinning technology were used for DRM. Due to the excellent catalytic performance of Pt itself, the CoPt-CeO2 catalyst had the highest DRM catalytic performance at 850 °C, with a methane (CH4) conversion of 94.12%, and remained stable in 24 h stability testing with almost no carbon deposition. The surface properties of the samples were characterized by Brunauer–Emmett–Teller (BET), temperature programmed reduction with H2 (H2-TPR), temperatureprogrammed desorption of CO2 (CO2-TPD), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that part of the reason for the excellent catalytic performance exhibited by adding noble metals to the catalyst is closely related to the high dispersion of active metals. More importantly, the addition of noble metals significantly increased the medium and strong alkaline sites of the catalysts. The abundant oxygen vacancies in CeO2 itself and the increased alkaline sites of noble metals were conducive to the CO2 adsorption and dissociation and the oxidation of deposited carbon. Moreover, the addition of noble metals promoted the interaction between the active metal and support. The results of this study provide a reference for the design of high-performance Co-based DRM catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Ziheng Zhen,Antai Li,Youwei Yang,Ying Hu,Jing Lv,Shouying Huang,Yue Wang,Xinbin Ma
Cu/CeO 2 catalysts have been wildly used for the hydrogenation of carbon-oxygen bonds reactions due to their excellent catalytic performance. It is widely accepted that the Cu 0 -Cu σ+ interface could be the primary active sites during the reaction, but how to form and maintain highly dispersed such species remains challenging under the reaction conditions of high temperature and H 2 partial pressure. In this work, we proposed an effective strategy to construct stable Cu 0 -Cu σ+ interface sites over the Cu/CeO 2 catalysts by in situ N 2 O-involved oxidation treatment . It was evidenced that the sequential oxidation-reduction by N 2 O and H 2 broke the grain boundaries of Cu nanoparticles and therefore facilitated the formation of the active Cu 0 -Cu σ+ sites, leading to an enhanced activity. However, a rapid deactivation was observed after this temporary enhancement due to the aggregation of copper species. We further introduced some additional cerium species during catalyst preparation. The 16Cu/CeO 2 -1Ce catalyst prepared by post-impregnation of 1 wt% cerium achieved a stable performance of 90.6% MA conversion after the N 2 O-involved oxidation treatment, which was much higher than that of 26.2% over the 16Cu/CeO 2 catalyst. It was demonstrated that the strong interaction between the formed CeO 2 and reconstructed Cu species prevented the metal sintering and increased the fraction of the Cu 0 -Cu σ+ sites. This method that combined in situ N 2 O-involved oxidation treatment and cerium modification may offer potential in engineering stable active sites for high-performance catalysts in the hydrogenation of carbon-oxygen bonds.
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
CHEMISTRY-A EUROPEAN JOURNAL
·
2017
·Vol. 23
·期 44
·10690-10697
·
IF 5.317
Yue Yu,Li Gao,Xianchun Liu,Yuanhong Wang,Shuangxi Xing
Graphical In the frame : Incorporating CeO 2 nanoparticles in zeolitic imidazolate framework-8 (ZIF-8) followed by high-temperature pyrolysis generated CeO 2 @N-doped carbon materials (see figure), which showed excellent activity in the oxygen reduction reaction, high tolerance to methanol crossover, and high stability. Incorporation of CeO 2 nanoparticles into the cavity of zeolitic imidazolate framework-8 (ZIF-8) was followed by high-temperature pyrolysis to generate CeO 2 @N-doped carbon materials. Introduction of the CeO 2 nanoparticles greatly enhanced the catalytic activity of the ZIF-8-derived carbon materials in the oxygen reduction reaction (ORR) owing to the presence of Ce 3+ and oxygen vacancies with high content of chemisorbed oxygen in CeO 2 and the well-maintained skeleton of the original ZIF-8 with uniform mesoporous structure. The material treated at 900 °C (CeO 2 @N-C-900) showed excellent ORR catalytic activity in both acidic and alkaline electrolyte. The ORR onset and half-wave potentials of CeO 2 @N-C-900 were 1.003 and 0.908 V versus RHE, respectively, in 0.1 m KOH aqueous solution, which are comparable to those of Pt/C catalysts. Furthermore, it exhibited much better stability and methanol crossover tolerance than Pt/C, indicative of its good potential for applications in energy conversion.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 22
·20495-20512
·
IF 2.22
Jiang Haopeng,Li Xin,Chen Songtao,Wang Huiqin,Huo Pengwei
g-C 3 N 4 quantum dots (CN QDs)-decorated mesoporous CeO 2 composite photocatalyst was prepared by hydrothermal method. The characterized results exhibit that the CN QDs are successfully coupled with mesoporous CeO 2 , and the photoelectronic response is effectively enhanced. The photocatalytic activity was tested by CO 2 reduction, and the results showed that when the loading of CN QDs was 0.75 wt%, the composite photocatalyst has the best photocatalytic activity. After 10 h of UV irradiation, the yields of CO and CH 4 were 22.48 µmol/g and 15.81 µmol/g, respectively. Some of the electrons generated within m-CeO 2 participated in the CO 2 reduction reaction and some were transferred to CN QDs through the two-phase interface to participate in the CO 2 catalytic reaction. The oxygen vacancies in m-CeO 2 can adsorb CO 2 and the introduced CN QDs can excite more oxygen vacancies with m-CeO 2 heterostructure, thereby adsorbing more CO 2 and photoreduction electrons.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xing Yi,Yan Wang,Zongpeng Zou,Yuan He,Li Lv,Wenxiang Tang,Tao Zhang,Shengwei Tang
The microreactor coupled mini-channel microdroplets extraction and separation technology (MES) was developed by adding polyvinyl alcohol (PVA) into microdroplets, realizing the controllable synthesis of a series of mono-component and multi-component metal oxide nano particles (MONPs). A double-layer surfactant structure composed of Span20 (oil phase surfactant) and PVA (water phase surfactant) was designed as a barrier to intercept and collect the precipitated salt at the microdroplet interface, the addition of PVA reduces the loss of salt components during the extraction process from 41.7 wt% to 1.1 wt%. The size control of mono-component MONPs (CuO, Co 3 O 4 , and NiO) was achieved using MES method. Furthermore, in the application direction of preparing multi-component MONPs, the advantages of MES in preparing multi-component catalysts (Ni/CeO 2 ) were verified. TEM, XRD, H 2 -TPR, CO 2 -TPD, XPS, BET et al. characterizations have shown that Ni entered the lattice of CeO 2 during precipitation to form a Ni-O-Ce solid solution and was therefore highly dispersed in CeO 2 . Ni/CeO 2 -MES showed high CO 2 conversion and CO selectivity in reverse water gas shift (RWGS) testing compared to Ni/CeO 2 catalysts prepared by impregnation method which has excellent thermal stability and can maintain over 99 % CO selectivity even after 50 h of reaction at 600 °C. The MES method was proved to be an efficient synthesis technology for MONPs and can be extended to a variety of metal oxides catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Dong Wang,Rong Tan,Haibo Yu,Hong Chen,Xiao Ma,Huizhang Zhao,Xingyu Kang,Hairui Fang
Real-time monitoring of toxic and harmful hydrogen sulfide (H 2 S) is crucial in the extraction process of fossil fuels. However, in the process of detecting H 2 S, there will be difficulties in desorption, low response, poor anti-interference ability, and poor long-term stability. The multidimensional copper oxide (CuO) composite cerium oxide (CeO 2 ) was synthesized by hydrothermal method and calcination techniques, and a gas sensor with easy desorption, high response, strong anti-interference ability, and excellent long-term stability for monitoring H 2 S was effectively prepared. Through various characterization tests such as X-ray diffraction (XRD) and scanning electron microscope (SEM), it was found that the composite material has multidimensional characteristics. When detecting 100 parts per million (ppm) of H 2 S at the optimal operating temperature of 180℃, the CuO/CeO 2 gas sensor with the optimal ratio (n Cu : n Ce =1:1) showed an extremely high response (2010). At the same time, the gas sensor has extremely strong anti-interference ability and excellent long-term stability. In addition, these excellent H 2 S sensing properties are attributed to the excellent oxygen storage characteristics of CeO 2 and the synergistic effect of CuO and CeO 2 . This provides more active sites for the absorption of H 2 S. Finally, to achieve real-time monitoring and alarm of H 2 S, a portable real-time monitoring and alarm device was made. When detecting different concentrations of H 2 S, it will flash corresponding color lights and give an alarm to achieve the monitoring function and ensure the safety and health of workers. The multi-dimensional CuO/CeO 2 prepared has excellent gas sensing performance, providing a new method for H 2 S detection.
研究领域:
材料科学
·
传感器技术
·
环境监测
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2018
·
IF 2.179
Guofang Zhang,Yiming Li,Zhonghui Hou,Jianyi Xv,Qingchun Wang,Yanghuan Zhang
The Cu 2+ and Zn 2+ co-doped CeO 2 -based solid solutions were synthesized via hydrothermal method . The microstructure and the spectra features of the solid solutions were characterized systematically. The XRD results showed that the dopants were incorporated into the CeO 2 lattice to form Ce 1-x Cu 0.5x Zn 0.5x O 2 solid solutions when x was lower than 0.14. The cell parameters and the crystalline size decreased linearly, and the lattice strain gradually increased with increasing the doping level. The TEM patterns showed that the particle size in the solid solution was lower than 10 nm which is in accordance with the XRD results. The ICP analysis indicated that the real doped content in the solid solution was close to the nominal proportion. XPS proved that the Ce 3+ component was increased by doping. The Raman and PL spectra indicated that the lattice distortion and the oxygen vacancies also increased following the same trend. At the same time, the synergistic effects of two ions co-doped solid solutions were studied by comparing them with that of single ions doped samples. The catalysis effects of Cu 2+ and Zn 2+ co-doped CeO 2 -based solid solutions on the hydrogen storage electrochemical and kinetic properties of Mg 2 Ni alloys were detected. The electrochemistry properties of the Mg 2 Ni-Ni-5 wt% Ce 1-x Cu 0.5x Zn 0.5x O 2 composites indicated that the doped catalysts could provide better optimizations to improve the maximum discharge capacities and the discharge potentials. On the other hand, the charge transfer abilities on the surface and diffusion rate of H atoms in the bulk of alloys also got improved. The DSC measurements showed that the hydrogen desorption activation of the hydrogenated composites with Ce 0.88 Cu 0.06 Zn 0.06 O 2 solid solutions decreased to 77.03 kJ mol −1 , while that of the composites with pure CeO 2 was 97.62 kJ mol −1 . The catalysis effect was enhanced by the doped content increase that means that the catalysis mechanism had close links to the oxygen vacancy concentration and the lattice defects in the solid solutions. On the other hand, the doped Cu 2+ and Zn 2+ ions could also play an important role in the catalytic process.
研究领域:
材料科学
·
电化学
·
催化作用
✓ 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）