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Cu(In 4

Ga)Se2 3

二氧化碳 3

光催化 3

5G 2

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氧化铈 2

碳中和 2

纳米颗粒 2

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(GaxIn1−x)2O3薄膜;带隙可调谐;磁控溅射 1

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High purity Mn

Xiaoqiang SHAN, Fenghua GUO, Wenqian XU, Xiaowei TENG

《能源前沿(英文)》 2017年 第11卷 第3期   页码 383-400 doi: 10.1007/s11708-017-0485-3

摘要: Developing electrodes with high specific energy by using inexpensive manganese oxides is of great importance for aqueous electrochemical energy storage (EES) using non-Li charge carriers such as Na-or K-ions. However, the energy density of aqueous EES devices is generally limited by their narrow thermodynamic potential window (~1.23 V). In this paper, the synthesis of high purity layered Mn O nanoparticles through solid state thermal treatment of Mn O spinel nanoparticles, resulting in a chemical formula of [Mn ][Mn O ], evidenced by Rietveld refinement of synchrotron-based X-ray diffraction, has been reported. The electro-kinetic analyses obtained from cyclic voltammetry measurements in half-cells have demonstrated that Mn O electrode has a large overpotential (~ 0.6 V) towards gas evolution reactions, resulting in a stable potential window of 2.5 V in an aqueous electrolyte in half-cell measurements. Symmetric full-cells fabricated using Mn O electrodes can be operated within a stable 3.0 V potential window for 5000 galvanostatic cycles, exhibiting a stable electrode capacity of about 103 mAh/g at a C-rate of 95 with nearly 100% coulombic efficiency and 96% energy efficiency.

关键词: manganese oxides Mn5O8     high voltage     aqueous Na-ion storage    

On the monolayer dispersion behavior of Co<sub>3sub>O<sub>4sub> on HZSM-5 support: designing applicablecatalysts for selective catalytic reduction of nitrogen oxides by ammonia

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1741-1754 doi: 10.1007/s11705-023-2332-x

摘要: Based on monolayer dispersion theory, Co3O4/ZSM-5 catalysts with different loadings have been prepared for selective catalytic reduction of nitrogen oxides by ammonia. Co3O4 can spontaneously disperse on HZSM-5 support with a monolayer dispersion threshold of 0.061 mmol 100 m–2, equaling to a weight percentage around 4.5%. It has been revealed that the quantities of surface active oxygen (O2) and acid sites are crucial for the reaction, which can adsorb and activate NOx and NH3 reactants effectively. Below the monolayer dispersion threshold, Co3O4 is finely dispersed as sub-monolayers or monolayers and in an amorphous state, which is favorable to generate the two kinds of active sites, hence promoting the performance of ammonia selective catalytic reduction of nitrogen oxide. However, the formation of crystalline Co3O4 above the capacity is harmful to the reaction performance. 4% Co3O4/ZSM-5, the catalyst close to the monolayer dispersion capacity, possesses the most abundant active O2 species and acidic sites, thereby demonstrating the best reaction performance in all the samples. It is proposed the optimal Co3O4/ZSM-5 catalyst can be prepared by loading the capacity amount of Co3O4 onto HZSM-5 support.

关键词: Co3O4/ZSM-5     NOx-SCR by NH3     monolayer dispersion threshold effect     surface acid sites     surface active O2 anions    

CO<sub>2sub> methanation and co-methanation of CO and CO<sub>2sub> over Mn-promoted Ni/Al<sub>2sub>O<sub>3sub> catalysts

Kechao Zhao,Zhenhua Li,Li Bian

《化学科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 273-280 doi: 10.1007/s11705-016-1563-5

摘要: A series of Mn-promoted 15 wt-% Ni/Al O catalysts were prepared by an incipient wetness impregnation method. The effect of the Mn content on the activity of the Ni/Al O catalysts for CO methanation and the co-methanation of CO and CO in a fixed-bed reactor was investigated. The catalysts were characterized by N physisorption, hydrogen temperature-programmed reduction and desorption, carbon dioxide temperature-programmed desorption, X-ray diffraction and high-resolution transmission electron microscopy. The presence of Mn increased the number of CO adsorption sites and inhibited Ni particle agglomeration due to improved Ni dispersion and weakened interactions between the nickel species and the support. The Mn-promoted 15 wt-% Ni/Al O catalysts had improved CO methanation activity especially at low temperatures (250 to 400 °C). The Mn content was varied from 0.86% to 2.54% and the best CO conversion was achieved with the 1.71Mn-Ni/Al O catalyst. The co-methanation tests on the 1.71Mn-Ni/Al O catalyst indicated that adding Mn markedly enhanced the CO methanation activity especially at low temperatures but it had little influence on the CO methanation performance. CO methanation was more sensitive to the reaction temperature and the space velocity than the CO methanation in the co-methanation process.

关键词: Mn promotion     nickel catalysts     CO2 methanation     co-methanation of CO and CO2    

Li<sub>4sub>SiO<sub>4sub>-coated LiNi<sub>0.5sub>Mn<sub>1.5sub>O<sub>4sub> as the high performance

Shifeng YANG, Wenfeng REN, Jian CHEN

《能源前沿(英文)》 2017年 第11卷 第3期   页码 374-382 doi: 10.1007/s11708-017-0494-2

摘要: The preparation of Li SiO -coated LiNi Mn O materials by sintering the SiO -coated nickel-manganese oxides with lithium salts using abundant and low-cost sodium silicate as the silicon source was reported. The samples were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It was found that a uniform and complete SiO coating layer could be obtained at a suitable pH value of 10, which transformed to a good Li SiO coating layer afterwards. When used as the cathode materials for lithium-ion batteries, the Li SiO -coated LiNi Mn O samples deliver a better electrochemical performance in terms of the discharge capacity, rate capability, and cycling stability than that of the pristine material. It can still deliver 111.1 mAh/g at 20 C after 300 cycles, with a retention ratio of 93.1% of the stable capacity, which is far beyond that of the pristine material (101.3 mAh/g, 85.6%).

关键词: lithium-ion batteries     cathode material     LiNi0.5Mn1.5O4     lithium-ion conductor     coating    

Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1211-1223 doi: 10.1007/s11705-022-2145-3

摘要: The one-step highly selective oxidation of cyclohexane into cyclohexanone and cyclohexanol as the essential intermediates of nylon-6 and nylon-66 is considerably challenging. Therefore, an efficient and low-cost catalyst must be urgently developed to improve the efficiency of this process. In this study, a Co3O4–CeO2 composite oxide catalyst was successfully prepared through ultrasound-assisted co-precipitation. This catalyst exhibited a higher selectivity to KA-oil, which was benefited from the synergistic effects between Co3+/Co2+ and Ce4+/Ce3+ redox pairs, than bulk CeO2 and/or Co3O4. Under the optimum reaction conditions, 89.6% selectivity to KA-oil with a cyclohexane conversion of 5.8% was achieved over Co3O4–CeO2. Its catalytic performance remained unchanged after five runs. Using the synergistic effects between the redox pairs of different transition metals, this study provides a feasible strategy to design high-performance catalysts for the selective oxidation of alkanes.

关键词: Co3O4–CeO2 composite oxides     cyclohexanone     cyclohexanol     ultrasonic-assisted co-precipitation     selective oxidation     solvent-free    

Metal-organic framework loaded manganese oxides as efficient catalysts for low-temperature selective

Minhua Zhang, Baojuan Huang, Haoxi Jiang, Yifei Chen

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 594-602 doi: 10.1007/s11705-017-1668-5

摘要: A mild deposition method was used to fabricate Mn-based catalysts on a UiO-66 carrier for the selective catalytic reduction of NO by NH (NH -SCR). The catalyst with 8.5 wt-% MnO loading had the highest catalytic activity for NH -SCR with a wide temperature window (100–290 °C) for 90% NO conversion. Characterization of the prepared MnO /UiO-66 catalysts showed that the catalysts had the crystal structure and porosity of the UiO-66 carrier and that the manganese particles were well-distributed on the surface of the catalyst. X-ray photoelectron spectroscopy analysis showed that there are strong interactions between the MnO and the Zr oxide secondary building units of the UiO-66 which has a positive effect on the catalytic activity. The 8.5 wt-% MnO catalyst maintained excellent activity during a 24-h stability test and exhibited good resistance to SO poisoning.

关键词: metal-organic framework     selective catalytic reduction     manganese oxides     deNOx     SO2 resistance    

Rh<sub>2sub>O<sub>3sub>/hexagonal CePO<sub>4sub> nanocatalysts for N<sub>2sub>O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要: Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词: Rh2O3     CePO4     N2O decomposition    

Characterization and performance of V

Caiting LI, Qun LI, Pei LU, Huafei CUI, Guangming ZENG

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 156-161 doi: 10.1007/s11783-010-0295-x

摘要: A series of CeO supported V O catalysts with various loadings were prepared with different calcination temperatures by the incipient impregnation. The catalysts were evaluated for low temperature selective catalytic reduction (SCR) of NO with ammonia (NH ). The effects of O and SO on catalytic activity were also studied. The catalysts were characterized by specific surface areas (S ) and X–ray diffraction (XRD) methods. The experimental results showed that NO conversion changed significantly with the different V O loading and calcination temperature. With the V O loading increasing from 0 to 10 wt%, NO conversion increased significantly, but decreased at higher loading. The optimum calcination temperature was 400°C. The best catalyst yielded above 80% NO conversion in the reaction temperature range of 160°C–300°C. The formation of CeVO on the surface of catalysts caused the decrease of redox ability.

关键词: V2O5/CeO2 catalysts     NH3-SCR (selective catalytic reduction)     the incipient impregnation     low temperatures    

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 348-361 doi: 10.1007/s11783-011-0343-1

摘要: The UCD/CIT model was modified to include a process analysis (PA) scheme for gas and particulate matter (PM) to study the formation of secondary nitrate aerosol during a stagnant wintertime air pollution episode during the California Regional PM /PM Air Quality Study (CRPAQS) where detailed measurements of PM components are available at a few sites. Secondary nitrate is formed in the urban areas from near the ground to a few hundred meters above the surface during the day with a maximum modeled net increase rate of 4 μg·m ·d during the study episode. The secondary nitrate formation rate in rural areas is lower due to lower NO . In the afternoon hours, near-surface temperature can be high enough to evaporate the particulate nitrate. In the nighttime hours, both the gas phase N O reactions with water vapor and the N O heterogeneous reactions with particle-bound water are important for secondary nitrate formation. The N O reactions are most import near the surface to a few hundred meters above surface with a maximum modeled net secondary nitrate increase rate of 1 μg·m ·d and are more significant in the rural areas where the O concentrations are high at night. In general, vertical transport during the day moves the nitrate formed near the surface to higher elevations. During the stagnant days, process analysis indicates that the nitrate concentration in the upper air builds up and leads to a net downward flux of nitrate through vertical diffusion and a rapid increase of surface nitrate concentration.

关键词: secondary nitrate aerosol     N2O5 heterogeneous reaction     process analysis    

NiBO (B = Mn or Co) catalysts for NH-SCR of NO at low-temperature in microwave field

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1696-y

摘要:

● Microwave-assisted catalytic NH3-SCR reaction over spinel oxides is carried out.

关键词: Microwave field     Spinel oxides     NOx     Selective catalytic reduction    

Facile controlled synthesis of hierarchically structured mesoporous Li4Ti5O12/C/rGO composites as high-performance

Cehuang FU, Shuiyun SHEN, Ruofei WU, Xiaohui YAN, Guofeng XIA, Junliang ZHANG

《能源前沿(英文)》 2022年 第16卷 第4期   页码 607-612 doi: 10.1007/s11708-021-0798-0

摘要: In this paper, a facile strategy is proposed to controllably synthesize mesoporous Li4Ti5O12/C nanocomposite embedded in graphene matrix as lithium-ion battery anode via the co-assembly of Li4Ti5O12 (LTO) precursor, GO, and phenolic resin. The obtained composites, which consists of a LTO core, a phenolic-resin-based carbon shell, and a porous frame constructed by rGO, can be denoted as LTO/C/rGO and presents a hierarchical structure. Owing to the advantages of the hierarchical structure, including a high surface area and a high electric conductivity, the mesoporous LTO/C/rGO composite exhibits a greatly improved rate capability as the anode material in contrast to the conventional LTO electrode.

关键词: Li4Ti5O12     phenolic-resin-based carbon     mesoporous composite     graphene    

Chemical deactivation of V

Xiaodong WU, Wenchao YU, Zhichun SI, Duan WENG

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 420-427 doi: 10.1007/s11783-013-0489-0

摘要: V O -WO /TiO catalyst was poisoned by impregnation with NH Cl, KOH and KCl solution, respectively. The catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), N physisorption, Raman, UV-vis, NH adsorption, temperature-programmed reduction of hydrogen (H -TPR), temperature-programmed oxidation of ammonia (NH -TPO) and selective catalytic reduction of NO with ammonia (NH -SCR). The deactivation effects of poisoning agents follow the sequence of KCl>KOH>>NH Cl. The addition of ammonia chloride enlarges the pore size of the titania support, and promotes the formation of highly dispersed V=O vanadyl which improves the oxidation of ammonia and the high-temperature SCR activity. K ions are suggested to interact with vanadium and tungsten species chemically, resulting in a poor redox property of catalyst. More importantly, potassium can reduce the Br?nsted acidity of catalysts and decrease the stability of Br?nsted acid sites significantly. The more severe deactivation of the KCl-treated catalyst can be mainly ascribed to the higher amount of potassium resided on catalyst.

关键词: V2O5-WO3/TiO2     potassium chloride     poisoning     reducibility     acid sites    

Fe

Lifeng Zhang, Yifei Song, Weiping Wu, Robert Bradley, Yue Hu, Yi Liu, Shouwu Guo

《化学科学与工程前沿(英文)》 2021年 第15卷 第1期   页码 156-163 doi: 10.1007/s11705-020-1986-x

摘要: Unique self-assembled iron(II) molybdenum(IV) oxide (Fe Mo O ) mesoporous hollow spheres have been facilely constructed the bubble-template-assisted hydrothermal synthesis method combined with simple calcination. The compact assembly of small nanoparticles on the surface of the hollow spheres not only provides more active sites for the Fe Mo O , but also benefits the stability of the hollow structure, and thus improved the lithium storage properties of Fe Mo O . The Fe Mo O mesoporous hollow spheres exhibit high initial discharge and charge capacities of 1189 and 997 mA∙h∙g respectively, as well as good long-term cycling stability (866 mA∙h∙g over 70 cycles) when used as a lithium-ion battery anode. This feasible material synthesis strategy will inspire the variation of structural design in other ternary metal molybdates.

关键词: molybdates     Fe2Mo3O8     hollow spheres     lithium ion batteries     anodes    

Effects of gradient concentration on the microstructure and electrochemical performance of LiNi

Wenming Li, Weijian Tang, Maoqin Qiu, Qiuge Zhang, Muhammad Irfan, Zeheng Yang, Weixin Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 988-996 doi: 10.1007/s11705-020-1918-9

摘要: Nickel(Ni)-rich layered materials have attracted considerable interests as promising cathode materials for lithium ion batteries (LIBs) owing to their higher capacities and lower cost. Nevertheless, Mn-rich cathode materials usually suffer from poor cyclability caused by the unavoidable side-reactions between Ni ions on the surface and electrolytes. The design of gradient concentration (GC) particles with Ni-rich inside and Mn-rich outside is proved to be an efficient way to address the issue. Herein, a series of LiNi Co Mn O (LNCM622) materials with different GCs (the atomic ratio of Ni/Mn decreasing from the core to the outer layer) have been successfully synthesized via rationally designed co-precipitation process. Experimental results demonstrate that the GC of LNCM622 materials plays an important role in their microstructure and electrochemical properties. The as-prepared GC3.5 cathode material with optimal GC can provide a shorter pathway for lithium-ion diffusion and stabilize the near-surface region, and finally achieve excellent electrochemical performances, delivering a discharge capacity over 176 mAh·g at 0.2 C rate and exhibiting capacity retention up to 94% after 100 cycles at 1 C. The rationally-designed co-precipitation process for fabricating the Ni-rich layered cathode materials with gradient composition lays a solid foundation for the preparation of high-performance cathode materials for LIBs.

关键词: gradient concentration     Ni-rich     LiNi0.6Co0.2-Mn0.2O2     electrochemical performance     lithium-ion battery    

Simultaneous removal of NO and chlorobenzene on VO/TiO granular catalyst: Kinetic study and performance prediction

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1363-5

摘要:

• A V2O5/TiO2 granular catalyst for simultaneous removal of NO and chlorobenzene.

关键词: NOx     Chlorobenzene     Simultaneous removal     Kinetic study     Performance prediction     V2O5/TiO2     Graphical abstract    

标题 作者 时间 类型 操作

High purity Mn

Xiaoqiang SHAN, Fenghua GUO, Wenqian XU, Xiaowei TENG

期刊论文

On the monolayer dispersion behavior of Co<sub>3sub>O<sub>4sub> on HZSM-5 support: designing applicablecatalysts for selective catalytic reduction of nitrogen oxides by ammonia

期刊论文

CO<sub>2sub> methanation and co-methanation of CO and CO<sub>2sub> over Mn-promoted Ni/Al<sub>2sub>O<sub>3sub> catalysts

Kechao Zhao,Zhenhua Li,Li Bian

期刊论文

Li<sub>4sub>SiO<sub>4sub>-coated LiNi<sub>0.5sub>Mn<sub>1.5sub>O<sub>4sub> as the high performance

Shifeng YANG, Wenfeng REN, Jian CHEN

期刊论文

Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

期刊论文

Metal-organic framework loaded manganese oxides as efficient catalysts for low-temperature selective

Minhua Zhang, Baojuan Huang, Haoxi Jiang, Yifei Chen

期刊论文

Rh<sub>2sub>O<sub>3sub>/hexagonal CePO<sub>4sub> nanocatalysts for N<sub>2sub>O decomposition

Huan Liu, Zhen Ma

期刊论文

Characterization and performance of V

Caiting LI, Qun LI, Pei LU, Huafei CUI, Guangming ZENG

期刊论文

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

期刊论文

NiBO (B = Mn or Co) catalysts for NH-SCR of NO at low-temperature in microwave field

期刊论文

Facile controlled synthesis of hierarchically structured mesoporous Li4Ti5O12/C/rGO composites as high-performance

Cehuang FU, Shuiyun SHEN, Ruofei WU, Xiaohui YAN, Guofeng XIA, Junliang ZHANG

期刊论文

Chemical deactivation of V

Xiaodong WU, Wenchao YU, Zhichun SI, Duan WENG

期刊论文

Fe

Lifeng Zhang, Yifei Song, Weiping Wu, Robert Bradley, Yue Hu, Yi Liu, Shouwu Guo

期刊论文

Effects of gradient concentration on the microstructure and electrochemical performance of LiNi

Wenming Li, Weijian Tang, Maoqin Qiu, Qiuge Zhang, Muhammad Irfan, Zeheng Yang, Weixin Zhang

期刊论文

Simultaneous removal of NO and chlorobenzene on VO/TiO granular catalyst: Kinetic study and performance prediction

期刊论文