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different acid anions on highly efficient Ce-based catalysts for selective catalytic reduction of NO with NH₃

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1399-1411 doi: 10.1007/s11705-023-2345-5

摘要： Three kinds of Ce-based catalysts (CePO₄, CeVO₄, Ce₂(SO₄)₃) were synthesized and used for the selective catalytic reduction (SCR) of NO by NH₃. NH₃-SCR performances were conducted in the temperature range of 80 to 400 °C. The catalytic efficiencies of the three catalysts are as follow: CePO₄ > CeVO₄ > Ce₂(SO₄)₃, which is in agreement with their abilities of NH₃ adsorption capacities. The highest NO conversion rate of CePO₄ could reach about 95%, and the catalyst had more than 90% NO conversion rate between 260 and 320 °C. The effect of PO₄^3–, VO₄^3– and SO₄^2– on NH₃-SCR performances of Ce-based catalysts was systematically investigated by the X-ray photoelectron spectroscopy analysis, NH₃ temperature programmed desorption, H₂ temperature programmed reduction and field emission scanning electron microscopy tests. The key factors that can enhance the SCR are the existence of Ce⁴⁺, large NH₃ adsorption capacity, high and early H₂ consumptions, and suitable microstructures for gas adsorption. Finally, CePO₄ and CeVO₄ catalysts also exhibited relatively strong tolerance of SO₂, and the upward trend about 8% was detected due to the sulfation enhancement by SO₂ for Ce₂(SO₄)₃.

关键词： CePO₄ CeVO₄ Ce₂(SO₄)₃ selective catalytic reduction NO removal

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On the monolayer dispersion behavior of Co₃O₄ on HZSM-5 support: designing applicable

《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 NO_x 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 NO_x-SCR by NH₃ monolayer dispersion threshold effect surface acid sites surface active O₂^– anions

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Removal of ammonium and nitrate through Anammox and FeS-driven autotrophic denitrification

《环境科学与工程前沿（英文）》 2023年第17卷第6期 doi: 10.1007/s11783-023-1674-4

摘要：

● Simultaneous NH₄⁺/NO₃^– removal was achieved in the FeS denitrification system

关键词： Anammox Denitrification FeS NH₄⁺/NO₃⁻ Sulfammox

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Denitrification performance and sulfur resistance mechanism of Sm–Mn catalyst for low temperature NH-SCR

《化学科学与工程前沿（英文）》 2023年第17卷第5期页码 617-633 doi: 10.1007/s11705-022-2258-8

摘要： MnO_x and Sm–Mn catalysts were prepared with the coprecipitation method, and they showed excellent activities and sulfur resistances for the selective catalytic reduction of NO_x by NH₃ between 50 and 300 °C in the presence of excess oxygen. 0.10Sm–Mn catalyst indicated better catalytic activity and sulfur resistance. Additionally, the Sm doping led to multi-aspect impacts on the phases, morphology structures, gas adsorption, reactions process, and specific surface areas. Therefore, it significantly enhances the NO conversion, N₂ selectivity, and sulfur resistance. Based on various experimental characterization results, the reaction mechanism of catalysts and the effect of SO₂ on the reaction process about the catalysts were extensively explored. For 0.10Sm–Mn catalyst, manganese sulfate and sulfur ammonium cannot be generated broadly under the influence of SO₂ and the amount of surface adsorbed oxygen. The Bronsted acid sites strengthen significantly due to the addition of SO₂, enhancing the sulfur resistance of the 0.10Sm–Mn catalyst.

关键词： MnO_x Sm–Mn catalyst NH₃-SCR sulfur resistance

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Effective regeneration of thermally deactivated commercial V-W-Ti catalysts

Xuesong SHANG, Jianrong LI, Xiaowei YU, Jinsheng CHEN, Chi HE

《化学科学与工程前沿（英文）》 2012年第6卷第1期页码 38-46 doi: 10.1007/s11705-011-1167-z

摘要： An effective method for the regeneration of thermally deactivated commercial monolith SCR catalysts was investigated. Two types of regenerated solutions, namely NH Cl (1 mol/L) and dilute H SO (0.5 mol/L), were employed to treat the used catalyst. The effects of temperature and the regeneration process on the structural and textural properties of the catalysts were determined by X-ray diffraction, scanning electron microscopy, N adsorption/desorption, elemental analysis and Fourier transform infrared spectroscopy. The results suggest that the anatase phase of the used catalyst is maintained after exposure to high temperatures. Some of the catalytic activity was restored after regeneration. The catalyst regenerated by aqueous NH Cl had a higher activity than that of the catalyst treated by dilute H SO . The main reason is that the NH generated from the decomposition of NH Cl at high temperatures can be adsorbed onto the catalyst which promotes the reaction. The aggregated V O were partially re-dispersed during the regeneration process, and the intrinsic oxidation of ammonia with high concentrations of O is a factor that suppresses the catalytic activity.

关键词： V₂O₅-WO₃/TiO₂ catalysts thermal deactivation regeneration NH₄Cl dilute H₂SO₄ solution

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Phase equilibrium of the ternary system of NH 4 Cl—CaCl 2 —H 2 O at 50°C

Xia LI, Junsheng YUAN, Zhiyong JI, Jianxin CHEN,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 75-77 doi: 10.1007/s11705-009-0296-0

摘要： The equilibrium data on the ternary system of NHCl—CaCl—HO at 50°C were investigated using the wet-residue method. The experimental results show that there are three pure phase crystal areas of NHCl, 2NHCl·CaCl·3HO and CaCl·2HO, two mixture phase crystal areas of NHCl and 2NHCl·CaCl·3HO, and 2NHCl·CaCl·3HO and CaCl·2HO in the system. A new hydration double salt (2NHCl·CaCl·3HO) was found in the ternary equilibrium system for the first time.

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以NH₃OH⁺/NH₂NH₃⁺作为B位阳离子的无金属六方钙钛矿含能材料 Article

尚宇, 余志鸿, 黄瑞康, 陈劭力, 刘德轩, 陈晓娴, 张伟雄, 陈小明

《工程（英文）》 2020年第6卷第9期页码 1013-1018 doi: 10.1016/j.eng.2020.05.018

摘要：文中通过合理地选择分子组分，经由易于规模放大的简单合成路线，以NH₃OH⁺和NH₂NH₃⁺分别作为B位点阳离子构筑了两例无金属六方钙钛矿含能材料(H₂dabco)B(ClO₄)₃（分别命名为DAP-6和DAP-7，其中H_{2<与基于NH₄⁺阳离子构筑的立方钙钛矿类似物(H₂dabco)(NH₄)(ClO₄)₃相比，DAP-6和DAP-7有较高的晶体堆积密度和生成焓，从而具有更高的爆轰性能。}

关键词：含能材料单质炸药固体推进剂无金属六方钙钛矿

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CeO doping boosted low-temperature NH-SCR activity of FeTiO catalyst: A microstructure analysis and reaction

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-022-1539-2

摘要：

• CeO₂ doping significantly improved low-temperature NH₃-SCR activity on FeTiO_x.

关键词： NH₃-SCR CeO₂ doping Low-temperature NO_x removal Improved redox property In situ XAFS analysis

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用以产生高纯度涡旋波束的宽带圆极化透射阵 Correspondence

邱靓婕1,2,3,4,李秀萍1,2,3,4,齐紫航1,2,3,4,赵文禹1,2,3,4,黄雨菡5

《信息与电子工程前沿（英文）》 2023年第24卷第6期页码 927-934 doi: 10.1631/FITEE.2200539

摘要：测试的峰值增益为22.3 dBic，3-dB轴比带宽为27.6%。测试结果表明，本文提出的透射阵有潜力应用于高容量无线通信和高质量雷达成像方面。

关键词：轨道角动量；涡旋波束；透射阵；宽带；高纯度

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Enabling nickel ferrocyanide nanoparticles for high-performance ammonium ion storage

《化学科学与工程前沿（英文）》 2023年第17卷第2期页码 226-235 doi: 10.1007/s11705-022-2198-3

摘要： Prussian blue and its analogs are extensively investigated as a cathode for ammonium-ion batteries. However, they often suffer from poor electronic conductivity. Here, we report a Ni₂Fe(CN)₆/multiwalled carbon nanotube composite electrode material, which is prepared using a simple coprecipitation approach. The obtained material consists of nanoparticles with sizes 30–50 nm and the multiwalled carbon nanotube embedded in it. The existence of multiwalled carbon nanotube ensures that the Ni₂Fe(CN)₆/multiwalled carbon nanotube composite shows excellent electrochemical performance, achieving a discharge capacity of 55.1 mAh·g^–1 at 1 C and 43.2 mAh·g^–1 even at 15 C. An increase in the ammonium-ion diffusion coefficient and ionic/electron conductivity based on kinetic investigations accounts for their high performance. Furthermore, detailed ex situ characterizations demonstrate that Ni₂Fe(CN)₆/multiwalled carbon nanotube composite offers three advantages: negligible lattice expansion during cycling, stable structure, and the reversible redox couple. Therefore, the Ni₂Fe(CN)₆/multiwalled carbon nanotube composite presents a long cycling life and high rate capacity. Finally, our study reports a desirable material for ammonium-ion batteries and provides a practical approach for improving the electrochemical performance of Prussian blue and its analogs.

关键词： nickel ferrocyanides NH₄⁺ electrochemistry Prussian blue aqueous ammonium ion batteries

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Ammonia adsorption on graphene and graphene oxide: a first-principles study

Yue PENG, Junhua LI

《环境科学与工程前沿（英文）》 2013年第7卷第3期页码 403-411 doi: 10.1007/s11783-013-0491-6

摘要： Motivated by the recent realization of graphene sensor to detect gas molecules that are harmful to the environment, the ammonia adsorption on graphene or graphene oxide (GO) was investigated using first-principles calculation. The optimal adsorption and orientation of the NH molecules on the graphene surfaces were determined, and the adsorption energies ( ) as well as the Mulliken charge transfers of NH were calculated. The for the graphene are small and seem to be independent of the sites and orientations. The surface epoxy or hydroxyl groups can promote the adsorption of NH on the GO; the enhancement of the for the hydroxyl groups is greater than that for the epoxy groups on the surface. The charge transfers from the molecule to the surfaces also exhibit the same trend. The Br?nsted acid sites and Lewis acid sites could stably exist on the GO with surface hydroxyl groups and on the basal, respectively.

关键词： graphene oxide first-principles calculations NH₃ adsorption

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Rh₂O₃/hexagonal CePO₄ nanocatalysts for N₂O 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

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新闻媒体眼中的中国：新冠肺炎疫情下的案例研究 Research Article

黄宏1,2,3,4,陈哲学1,2,3,4,石宣化1,2,3,4,王晨旭1,2,3,4,何泽鹏1,2,3,4,金海1,2,3,4,张明新5,李宗亚5

《信息与电子工程前沿（英文）》 2021年第22卷第11期页码 1443-1457 doi: 10.1631/FITEE.2000689

摘要：我们主要想回答3个问题：（1）新冠肺炎疫情期间，国际媒体关注的焦点是什么？（2）媒体报道中国时的立场是什么？（3）媒体谈论中国时的态度是什么？例如，新冠肺炎疫情期间，国际媒体更加关注中国民生；在3月和4月，“中国疫苗进展”“特定药物和治疗”“美国病毒爆发”成为媒体最常见话题；在新闻态度方面，古巴、马来西亚、委内瑞拉对中国持正面态度，而法国、加拿大

关键词：国家形象；新冠肺炎；主题挖掘；实体；新闻立场；情感

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Pd/Fe3O4 supported on bio-waste derived cellulosic-carbon as a nanocatalyst for C–C coupling and electrocatalytic

《化学科学与工程前沿（英文）》 2022年第16卷第10期页码 1514-1525 doi: 10.1007/s11705-022-2158-y

摘要： The current work describes the synthesis of a new bio-waste derived cellulosic-carbon supported-palladium nanoparticles enriched magnetic nanocatalyst (Pd/Fe₃O₄@C) using a simple multi-step process under aerobic conditions. Under mild reaction conditions, the Pd/Fe₃O₄@C magnetic nanocatalyst demonstrated excellent catalytic activity in the Hiyama cross-coupling reaction for a variety of substrates. Also, the Pd/Fe₃O₄@C magnetic nanocatalyst exhibited excellent catalytic activity up to five recycles without significant catalytic activity loss in the Hiyama cross-coupling reaction. Also, we explored the use of Pd/Fe₃O₄@C magnetic nanocatalyst as an electrocatalyst for hydrogen evolution reaction. Interestingly, the Pd/Fe₃O₄@C magnetic nanocatalyst exhibited better electrochemical activity compared to bare carbon and magnetite (Fe₃O₄ nanoparticles) with an overpotential of 293 mV at a current density of 10 mA·cm^–2.

关键词： bio-waste cellulosic-carbon Pd/Fe₃O₄ Hiyama cross-coupling hydrogen evolution reaction recyclability

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Preparation and property characterization of PAA/Fe3O4 nanocomposite

WEI Shanshan, ZHANG Yi, XU Jiarui

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 233-237 doi: 10.1007/s11705-007-0042-4

摘要： PAA/FeO nanocomposites were prepared by mixing nano-FeOvent. The materials were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscope (FTIR), thermogravimetry analysis (TGA), dynamic ultra-micro hardness tester (DUMHT) and superconducting quantum interference device (SQUID) magnetometer. Results showed that PAA coordinated with nano-FeO to form a cross-linking structure. The presence of nano-FeO enhanced the thermal stability of the nanocomposite. The elasticity and hardness of the nanocomposite increased, and the indentation depth reduced with the increase of FeO content in the composites. The nanocomposites showed superparamagnetic properties at 300 K.

关键词： magnetometer superparamagnetic ultra-micro thermogravimetry transmission