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Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendlyslow synthesis methodology

《能源前沿(英文)》   页码 751-762 doi: 10.1007/s11708-023-0895-3

摘要: Dehydrogenation of formic acid (FA) is considered to be an effective solution for efficient storage and transport of hydrogen. For decades, highly effective catalysts for this purpose have been widely investigated, but numerous challenges remain. Herein, the PdxAu1−x (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) alloys over the whole composition range were successfully prepared and used to catalyze FA hydrogen production efficiently near room temperature. Small PdAu nanoparticles (5–10 nm) were well-dispersed and supported on the activated carbon to form PdAu solid solution alloys via the eco-friendly slow synthesis methodology. The physicochemical properties of the PdAu alloys were comprehensively studied by utilizing various measurement methods, such as X-ray diffraction (XRD), N2 adsorption–desorption, high angle annular dark field-scanning transmission electron microscope (HAADF-STEM), X-ray photoelectrons spectroscopy (XPS). Notably, owing to the strong metal-support interaction (SMSI) and electron transfer between active metal Au and Pd, the Pd0.5Au0.5 obtained exhibits a turnover frequency (TOF) value of up to 1648 h−1 (313 K, nPd+Au/nFA = 0.01, nHCOOH/nHCOONa = 1:3) with a high activity, selectivity, and reusability in the FA dehydrogenation.

关键词: FA dehydrogenation     face-centred cubic structures     PdAu solid solution alloy nanoparticles     slow synthesis methodology     SMSI effect    

Synthesis of

Lili ZHANG, Ming LIU, Shijun MA, Yaodong HUANG, Yongmei WANG

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 408-414 doi: 10.1007/s11705-013-1343-4

摘要: Two new -symmetric primary-secondary diamines were synthesized via the reaction of ( , )-1,2-diphenyl ethylene diamine with 3,5-ditert-butyl salicylaldehyde and salicylaldehyde, respectively, followed by reduction with NaBH . The combination of the ligand from 3,5-ditert-butyl salicylaldehyde with CuBr could effciently catalyze the Henry reaction to afford -nitroalkanols in moderate to good yields (up to 87%) and high enantioselectivities (up to 88% ). A possible mechanism of the reaction was proposed.

关键词: enantioselective Henry reaction     C1-symmetric diamines     asymmetric reaction     nitroalkanol    

Events and reaction mechanisms during the synthesis of an Al

M. ABDELLAHI, M. ZAKERI, H. BAHMANPOUR

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 123-129 doi: 10.1007/s11705-013-1325-6

摘要: An Al O -TiB nanocomposite was successfully synthesized by the high energy ball milling of Al, B O and TiO . The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermodynamic calculations showed that the composite formed in two steps via highly exothermic mechanically induced self-sustaining reactions (MSRs). The composite started to form at milling times of 9–10 h but the reaction was not complete. The remaining starting materials were consumed by increasing the milling time to 15 h. The XRD patterns of the annealed powders showed that aluminum borate is one of the intermediate products and that it is consumed at higher temperatures. Heat treatment of the 6-h milled sample at 1100 C led to a complete formation of the composite. Increasing the milling time to 15 h led to a refining of the crystallite sizes. A nanocomposite powder with a mean crystallite size of 35–40 nm was obtained after milling for 15 h.

关键词: ball milling     nanocomposite     Al2O3     TiB2    

Thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction

Xiashuang LUO, Yangge GUO, Hongru ZHOU, Huan REN, Shuiyun SHEN, Guanghua WEI, Junliang ZHANG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 767-777 doi: 10.1007/s11708-020-0667-2

摘要: Shape-controlled Pt-Ni alloys usually offer an exceptional electrocatalytic activity toward the oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells (PEMFCs), whose tricks lie in well-designed structures and surface morphologies. In this paper, a novel synthesis of truncated octahedral PtNi alloy catalysts that consist of homogeneous Pt-Ni alloy cores enclosed by NiO-Pt double shells through thermally annealing defective heterogeneous PtNi alloys is reported. By tracking the evolution of both compositions and morphologies, the outward segregation of both PtO and NiO are first observed in Pt-Ni alloys. It is speculated that the diffusion of low-coordination atoms results in the formation of an energetically favorable truncated octahedron while the outward segregation of oxides leads to the formation of NiO-Pt double shells. It is very attractive that after gently removing the NiO outer shell, the dealloyed truncated octahedral core-shell structure demonstrates a greatly enhanced ORR activity. The as-obtained truncated octahedral Pt Ni core-shell alloy presents a 3.4-folds mass-specific activity of that for unannealed sample, and its activity preserves 45.4% after 30000 potential cycles of accelerated degradation test (ADT). The peak power density of the dealloyed truncated octahedral Pt Ni core-shell alloy catalyst based membrane electrolyte assembly (MEA) reaches 679.8 mW/cm , increased by 138.4 mW/cm relative to that based on commercial Pt/C.

关键词: dealloyed Pt-Ni alloys     truncated octahedron     double-shell     thermal annealing     oxygen reduction reaction (ORR)    

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

《能源前沿(英文)》 doi: 10.1007/s11708-023-0908-2

摘要: The Haber-Bosch process is the most widely used synthetic ammonia technology at present. Since its invention, it has provided an important guarantee for global food security. However, the traditional Haber-Bosch ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. Under the serious pressure of energy and environment, a green, clean, and sustainable ammonia synthesis route is urgently needed. Electrochemical synthesis of ammonia is a green and mild new method for preparing ammonia, which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar, wind, or water energy, without greenhouse gas and toxic gas emissions. Herein, the basic mechanism of the nitrogen reduction reaction (NRR) to ammonia and nitrate reduction reaction (NO3 RR) to ammonia were discussed. The representative approaches and major technologies, such as lithium mediated electrolysis and solid oxide electrolysis cell (SOEC) electrolysis for NRR, high activity catalyst and advanced electrochemical device fabrication for NO3 RR and electrochemical ammonia synthesis were summarized. Based on the above discussion and analysis, the main challenges and development directions for electrochemical ammonia synthesis were further proposed.

关键词: electrochemical ammonia synthesis     nitrogen     nitrate     nitrogen reduction reaction (NRR) to ammonia     nitrate reduction reaction (NO–3 RR)    

Synthesis and characterization of magnesium hydroxide by batch reaction crystallization

Xingfu SONG, Shuying SUN, Dengke ZHANG, Jin WANG, Jianguo YU

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 416-421 doi: 10.1007/s11705-011-1125-9

摘要: Magnesium hydroxide with high purity and uniform particle size distribution was synthesized by the direct precipitation method using MgCl and NaOH as reactive materials and NaCl as additive to improve the crystallization behavior of the product. The particle size distribution, crystal phase, morphology, and surface area of magnesium hydroxide were characterized by Malvern laser particle size analyzer, X-ray diffraction (XRD), scanning electron microscope (SEM) and Branauer-Emmett-Teller (BET) method, respectively. The purity of products was analyzed by the chemical method. The effects of synthesis conditions on the particle size distribution and water content (filtration cake) of magnesium hydroxide were investigated. The results indicated that feeding mode and rate, and reaction temperature had important effects on water content and the particle size distribution of the product, and sodium chloride improved the crystallization behavior of magnesium hydroxide. The ball-like magnesium hydroxides with the particle size distribution of 6.0–30.0 μm and purity higher than 99.0% were obtained. This simple and mild synthesis method was promising to be scaled up for the industrial production of magnesium hydroxide.

关键词: magnesium hydroxide     direct precipitation method     industrial crystallization     particle size distribution    

Synthesis of vinylferrocene and the ligand-exchange reaction between its copolymer and carbon nanotubes

Ran SHI,Hai WANG,Ping TANG,Yuezhen BIN

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 171-178 doi: 10.1007/s11705-014-1428-8

摘要: To improve the dispersibility of carbon nanotubes (CNTs), poly(vinylferrocene- -styrene) (poly(Vf- -St)), was grafted onto the surface of CNTs by a ligand-exchange reaction. Poly(Vf- -St) was obtained by a radical copolymerization reaction using styrene and vinylferrocene as the monomers. The vinylferrocene was synthesized from ferrocene via a Friedel-Crafts acylation. The molecular weight, molecular weight distribution, and amount of Vf in the poly(Vf- -St) were 1.32 × 10 , 1.69 and 17.6% respectively. The degree of grafting of the copolymer onto the CNTs surface was calculated from thermogravimetric analysis and varied from 27.1% to 79.7%. The addition of the poly(Vf- -St) greatly promoted the dispersibility of the modified CNTs in anhydrous alcohol. The electrical conductivity of composites prepared from the polymer-grafted CNTs and copolymer (acrylonitrile, 1,3-butadiene and styrene, ABS) strongly depended on the degree of grafting. These results show that the amount of polymer grafted onto the surface of CNTs can be controlled and that the electrical properties of composites prepared with these grafted polymers can be tuned.

关键词: vinylferrocene     poly (Vf-co-St)     CNTs     dispersibility    

One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

《化学科学与工程前沿(英文)》 2009年 第3卷 第2期   页码 201-205 doi: 10.1007/s11705-009-0052-5

摘要: Sucrose char sulfonic acid efficiently catalyzed the one-pot three-component Mannich reaction of ketones, aromatic aldehydes and amines in ethanol to afford the corresponding -amino carbonyl compounds in good to excellent yields. A series of heteroaromatic -amino carbonyl compounds can be obtained when using 2-acetylpyrazine as substrate. This reaction can be performed under mild reaction conditions with clean reaction profiles and a simple workup procedure.

关键词: One–pot synthesis     b-amino ketone     char sulfonic acid     2-acetylpyrazine     catalysis    

Design, synthesis and HIV-RT inhibitory activity of novel thiazolidin-4-one derivatives

Hua CHEN, Zaihong GUO, Qingmei YIN, Xiaoxu DUAN, Yunjing GU, Xiaoliu LI

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 231-237 doi: 10.1007/s11705-010-1022-7

摘要: A series of 2-aryl-3-(4,5,6-trimethylpyrimidin-2-yl) thiazolidin-4-ones ( – ) and their derivatives bearing a lipophilic substituent, like acetoxy group ( – ), propionyloxy group ( – ), methyl ( and ) at C-5 on thiazolidin-4-one ring were designed, synthesized and evaluated for their HIV-RT inhibitory activity. Using self-catalyzed Pummerer reaction, compounds – and – were obtained in good yield (63.1% 75.2%). Preliminary anti-HIV-RT test of these derivatives indicated that compounds – , (propionyloxy group at C-5) showed moderate HIV-RT inhibitory activity and compounds and with methyl at C-5 showed a weak HIV-RT inhibitory activity. Structure activity relationship analysis suggested that the substituted groups on C-5 would be unfavorable to anti-HIV-RT activity and that the steric effect might play a critical role in the anti-HIV RT activity.

关键词: 5-subsituted thiazolidin-4-ones     Pummerer reaction     anti-HIV-RT activity     SARs    

Technology for the preparation and application of cermet coatings and claddings in thermal power plants

Zongde LIU, Miao LIU, Liping ZHAO

《能源前沿(英文)》 2011年 第5卷 第3期   页码 257-262 doi: 10.1007/s11708-010-0129-3

摘要: This paper introduces the applied background of wear and corrosion-resistant materials in the electricity industry. Next, the paper summarizes the development of preparation technology for cermets and cermet coatings and claddings, finally explaining the application and development of submicron-grain cermet coatings and claddings through reaction synthesis technology.

关键词: cermets     cermet coatings/claddings     electro-thermal explosion spraying     reaction synthesis    

Preparation of Cu/ZrO

Xinmei LIU, Shaofen BAI, Huidong ZHUANG, Zifeng YAN

《化学科学与工程前沿(英文)》 2012年 第6卷 第1期   页码 47-52 doi: 10.1007/s11705-011-1170-4

摘要: Cu/ZrO catalysts for methanol synthesis from CO /H were respectively prepared by deposition coprecipitation (DP) and solid state reaction (SR) methods. There is an intimate interaction between copper and zirconia, which strongly affects the reduction property and catalytic performance of the catalysts. The stronger the interaction, the lower the reduction temperature and the better the performance of the catalysts. Surface area, pore structure and crystal structure of the catalysts are mainly controlled by preparation methods and alkalinity of synthesis system. The conversion of CO and selectivity of methanol are higher for DP catalysts than for SP catalysts.

关键词: Cu/ZrO2     methanol synthesis     deposition coprecipitation     solid state reaction     CO2/H2    

含稀释剂的Al-Cr2O3体系燃烧合成反应热力学分析与反应模型

张衍诚,潘冶,张传

《中国工程科学》 2004年 第6卷 第6期   页码 63-67

摘要:

对含稀释剂Al203和Cr<sub>2</sub>0<sub>3</sub>的Al-Cr<sub>2</sub>0<sub>3</sub>体系燃烧合成反应进行了热力学计算与分析,讨论了起始反应温度T<sub>0</sub>、稀释剂Al<sub>2</sub>O<sub>3</sub>和Cr<sub>2</sub>O<sub>3</sub>的含量对绝热反应温度7^的影响,并得出T<sub>0</sub>与T<sub>ad</sub>在特定温度段上的近似线性关系以及该关系在指导材料成分设计上的应用;揭示了反应驱动力——Gibbs自由能(AG)随反应温度(T)的变化关系,得出该体系的反应为扩散控制型反应;结合实验结果与分析,描述了该体系热爆反应的微观模型。

关键词: 金属陶瓷     燃烧合成     Al-Cr203体系     热力学     反应模型    

瑞德西韦核碱基单元的连续流合成 Article

郭永兴, 刘敏杰, 姜梅芬, 陶媛, 程荡, 陈芬儿

《工程(英文)》 2023年 第21卷 第2期   页码 92-100 doi: 10.1016/j.eng.2021.07.029

摘要:

本研究通过五步连续流合成了抗病毒药物瑞德西韦的核碱基单元7-溴吡咯[2,1-f][1‒2,4]三嗪-4-胺。采用间歇式合成化学方法,利用广泛可用且廉价的起始原料吡咯,通过顺序流动操作成功生产了7-溴吡咯[2,1-f][1‒2,4]三嗪-4-胺。在最佳流动条件下,7-溴吡咯[2,1-f][1‒2,4]三嗪-4-胺的分离收率为14.1%,总停留时间为79 min,通量为2.96 g∙h−1,总停留时间明显短于批处理程序中消耗的总时间(大于26.5 h)。在流动中,有利地促进了涉及危险和不稳定的中间体的高度放热的Vilsmeier-Haack 和N-胺化反应、氧化液-液双相转化及需要严格低温条件的溴化反应。这种合成方法的显著特点是,通过部署专用设备和分离单元,将后处理程序完全集成到反应序列中,从而形成一个精简的连续流系统,最大限度地提高整个过程的效率。该方法是一种更环保、更可持续的高效、安全地制备核碱基单元的方法。

关键词: 流动化学     连续多步合成     微反应技术     反应分离集成    

Synthesis of cobalt vanadium nanomaterials for efficient electrocatalysis of oxygen evolution

Meifeng Hao, Mingshu Xiao, Lihong Qian, Yuqing Miao

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 409-416 doi: 10.1007/s11705-017-1689-0

摘要:

A low-cost and high-activity catalyst for oxygen evolution reaction (OER) is the key to the water splitting technology for hydrogen generation. Here we report the use of three solvents, DMF, ethanol and glycol, in the solvothermal synthesis of three nano-catalysts, Co3(VO4)2-I, Co3(VO4)2-II, and Co3(VO4)2-III, respectively. Transmission electron microscope shows Co3(VO4)2-I, II, and III exist as ultrafine nanosheets, ultrathin nanofilms, and ultrafine nanosheet-comprised microspheres, respectively. These Co3(VO4)2 catalysts exhibit OER electrocatalysis, among which the Co3(VO4)2-II shows the lowest onset overpotential of 310 mV and only requires a small overpotential of 330 mV to drive current density of 10 mA/cm2. Due to their high surface free energy, the ultrathin nanofilms of Co3(VO4)2-II exhibits a good immobilization effect with the high electrocatalytic activity for OER.

关键词: Co3(VO4)2     oxygen evolution reaction     electrocatalyst     water splitting    

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1700-1712 doi: 10.1007/s11705-022-2207-6

摘要: The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha. Herein, for a better catalyst design and operation parameters optimization, the reaction pathways and equilibrium yields for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins were analyzed thermodynamically. The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways, respectively. However, the formation of light paraffin severely limits the maximum selectivity toward light olefins. The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins. The results are thus useful as a direction for future catalyst improvements, facilitating superior reaction pathways to enhance light olefins. In addition, the equilibrium yield of light olefins increased with increasing the chain length, and the introduction of cyclo-paraffin inhibits the formation of light olefins. High temperatures and low pressures favor the formation of ethylene, and moderate temperatures and low pressures favor the formation of propylene. n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90% and 55.77%, respectively. This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词: naphtha     catalytic pyrolysis     reaction pathway     equilibrium yield    

标题 作者 时间 类型 操作

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendlyslow synthesis methodology

期刊论文

Synthesis of

Lili ZHANG, Ming LIU, Shijun MA, Yaodong HUANG, Yongmei WANG

期刊论文

Events and reaction mechanisms during the synthesis of an Al

M. ABDELLAHI, M. ZAKERI, H. BAHMANPOUR

期刊论文

Thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction

Xiashuang LUO, Yangge GUO, Hongru ZHOU, Huan REN, Shuiyun SHEN, Guanghua WEI, Junliang ZHANG

期刊论文

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

期刊论文

Synthesis and characterization of magnesium hydroxide by batch reaction crystallization

Xingfu SONG, Shuying SUN, Dengke ZHANG, Jin WANG, Jianguo YU

期刊论文

Synthesis of vinylferrocene and the ligand-exchange reaction between its copolymer and carbon nanotubes

Ran SHI,Hai WANG,Ping TANG,Yuezhen BIN

期刊论文

One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

期刊论文

Design, synthesis and HIV-RT inhibitory activity of novel thiazolidin-4-one derivatives

Hua CHEN, Zaihong GUO, Qingmei YIN, Xiaoxu DUAN, Yunjing GU, Xiaoliu LI

期刊论文

Technology for the preparation and application of cermet coatings and claddings in thermal power plants

Zongde LIU, Miao LIU, Liping ZHAO

期刊论文

Preparation of Cu/ZrO

Xinmei LIU, Shaofen BAI, Huidong ZHUANG, Zifeng YAN

期刊论文

含稀释剂的Al-Cr2O3体系燃烧合成反应热力学分析与反应模型

张衍诚,潘冶,张传

期刊论文

瑞德西韦核碱基单元的连续流合成

郭永兴, 刘敏杰, 姜梅芬, 陶媛, 程荡, 陈芬儿

期刊论文

Synthesis of cobalt vanadium nanomaterials for efficient electrocatalysis of oxygen evolution

Meifeng Hao, Mingshu Xiao, Lihong Qian, Yuqing Miao

期刊论文

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

期刊论文