检索结果-南通市图书馆

A hierarchically structured tin-cobalt composite with an enhanced electronic effect for high-performance CO_(2) electroreduction in a wide potential range

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第1期76卷 462-469,I0012页

作者： Xingxing Jiang Xuan Li Yan Kong Chen Deng Xiaojie Li Qi Hu Hengpan Yang Chuanxin He Institute of Microscale Optoelectronics College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060GuangdongChina

Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction.

关键词： Hierarchic structure Tin-cobalt bimetallic oxide electronic effect CO_(2)electroreduction Wide potential range

Pt-Ni core-shell structure with Pt-skin and electronic effect on catalytic performance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第11期63卷 260-267页

作者： Chong Yao Dandan Ma Jie Luo Yixin Chen Min Tian Haoxuan Xie Chunshan Lu Feng Feng Xiaoliang Xu Qingtao Wang Qunfeng Zhang Xiaonian Li State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014China

In order to improve the catalytic performance of the nitrobenzene hydrogenation rearrangement to prepare p-aminophenol,a bimetallic Pt-Ni/C(PNC)catalyst was synthesized.Taking advantage of the synergistic effect of Ni and Pt to enhance product selectivity and catalytic performance stability,the electrons in Ni are moved to Pt by the electron effect,which affects the catalyst’s ability to activate H_(2)as well as the amount of hydrogen activated.Furthermore,due to the strong Pt(5d)-Ni(3d)coupling effect,Ni can effectively maintain Pt stability in the acidic system and reduce Pt dissolution.The stability of the PNC can be found to be greatly enhanced compared to the Pt/C(PC)catalyst,and p-aminophenol selectivity is greatly enhanced,showing excellent catalytic performance.

关键词： Nitrobenzene p-Aminophenol Pt-Ni/C bimetallic catalyst electronic effect Pt(5d)-Ni(3d)coupling

electronic effect on the optical properties and sensing ability of AIEgens with ESIPT process based on salicylaldehyde azine

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第1期61卷 76-87页

作者： Zhiming Wang Fan Zhou Jing Wang Zujin Zhao Anjun Qin Zhenqiang Yu Ben Zhong Tang State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China HKUST-Shenzhen Research Institute Shenzhen 518057 China School of Petrochemical Engineering Shenyang University of Technology (SUT) Liaoyang 111003 China College of Chemistry and Environmental Shenzhen University Shenzhen 518000 China Department of Chemistry The Hong Kong University of Science & Technology (HKUST) Hong Kong 999077 China

Two novel AIE-active salicylaldehyde azine(SAA) derivatives with a typical excited-state intramolecular proton transfer(ESIPT) process are prepared by introducing electron-withdrawing and donating groups at para-position of phenolic hydroxyl group(CN-SAA and TPA-SAA). The effect of the proton activity in SAA framework on their optical behaviors is investigated spectroscopically. The results from NMR and solvation measurements show that the proton of phenolic hydroxyl group has higher activity when there are electron-withdrawing groups, and the absorption and fluorescence spectra in buffers with different pH also provide the same results. After inviting F. as a nucleophilic probe, this proton activity difference in CN-SAA and TPA-SAA becomes more obvious. The potential application of both molecules is investigated. TPA-SAA exhibits good quantitative sensing ability towards F. with a fluorescence "turn-on" mode, whereas the aggregates of TPA-SAA can selectively and sensitively detect Cu2+ in aqueous solution. From these results, a structure-property relationship is established: the occurrence of ESIPT process will become much easier when linking electron-withdrawing groups at the para-position of phenolic hydroxyl group(e.g., CN-SAA),and it is better to introduce electron-donating groups to enhance the sensing ability towards ions(e.g., TPA-SAA). This work will provide guidance for further design and preparation of AIE-active luminogens with ESIPT process for sensing applications.

关键词： AIE ESIPT electronic effect proton activity ion sensor

electronic effect of Carbon Support on Pt Catalyst Supported on Graphite Intercalation Compound

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2010年第3期26卷 465-471页

作者： WEI Ang WANG Qing-jing ZHAO Xiao-hui ZHANG Shu-yong Key Lab of Colloid and Interface Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

Graphite intercalation compounds（GIC） were tested as an experimental model for studying the electronic effect of carbon support on the catalytic activity and poisoning tolerance of Pt catalyst for direct methanol fuel cells. The GIC samples with different intercalation degrees were prepared by electrolyzing graphite flake in H2SO4 for varying the periods of time. The GIC-supported Pt catalyst was deposited electrochemically. The catalytic activity and poisoning tolerance of the GIC-supported Pt catalysts were evaluated. It was found that GIC with sulfate anion as intercalate was able to catalyze methanol electrooxidation, which could be related to the positive charges generated on the graphite layer upon intercalation. As intercalation degree increased, the catalytic activity of the GIC-supported Pt catalyst decreased while the poisoning tolerance improved. This suggests that electron donation from support to catalyst had great effect on both catalytic activity and poisoning tolerance of Pt catalyst. And intercalation can be adopted as another important way to make modification on carboneous catalyst support.

关键词： Catalyst support electronic effect Graphite intercalation compound Catalytic activity Poisoning tolerance

Influence of electronic effect on Methane Catalytic Combustion over PdNi/Al2O3

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2013年第5期29卷 952-955页

作者： PAN Xi-qiang ZHANG Yi-bo ZHANG Bin MIAO Zhen-zhen WU Tian-xiao YANG Xiang-guang Laboratory of Green Chemistry and Process Changchun Institute of Applied Chemistry Chinese Academemy of Sciences Changchun 130022 P R. China University of Chinese Academy of Sciences Beijing 100049 P. R. China

A series of PdNi/Al2O3 catalysts with different compositions was prepared by co-reduction method. The influence of Ni amount on the catalytic combustion of methane was studied. X-ray diffractometry and X-ray photo- electron spectroscopy were employed to characterize the dispersion and electronic state of the active phase. Tempe- rature-programmed oxidation was carried out to study the thermal stability affected by Ni doping. It has been demon- strated that Ni addition changed particle size and oxidation state of PdOx. The results indicate that the promotion of Ni to the Pd/Al2O3 resulted from both size effect and electronic effect. In addition, the thermal stability of the Ni-doped catalysts were enhanced.

关键词： Methane combustion Palladium Nickel Size effect electronic effect

Regulating electronic environment on alkali metal-doped Cu@NS-SiO_(2) for selective anisole hydrodeoxygenation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

绿色化学工程(英文) 2023年第3期4卷 294-302页

作者： Xiaofei Wang Xiaoxue Han Li Kang Shixiang Feng Meiyan Wang Yue Wang Shouying Huang Yujun Zhao Shengping Wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure.Herein,we synthesized a series of novel Cu-based catalysts,Cu@NS-SiO_(2)(NS=nano sphere)and alkali metals(Na,K,Rb,and Cs)doped Cu@NS-SiO_(2),and applied them in hydrodeoxygenation reaction of anisole.High Cu dispersion was presented on all catalysts.The modification of alkali metals on Cu@NS-SiO_(2) significantly enhanced the electron density of Cu sites in the following order:Cs>Rb>K>Na,among which Cs decreased the Cu_(2)p_(3)/2 binding energy most(by 0.7 eV).Moreover,the modification did not substantially affect the geometric structure of Cu species.This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole,and thus promoted the selectivity of benzene.Compared with Cu@NS-SiO_(2)(~59%),the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO_(2) at~83%.

关键词： Anisole Hydrodeoxygenation Arenes Alkali metal electronic effect

electronic effectS OF POLYFLUORINATED SUBSTITUENTS ON THE POLYMERIZATION AND THE PROPERTIES OF POLYTHIOPHENES

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 1997年第1期15卷 15-23页

作者：张旭庆沈学明杨士勇陆伟张景云 Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200232

Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the electrochemical polymerization of thiophene monomers and properties of the obtained polymers were analyzed. The introduction of a fluoroether functional group at the 3-position of the thiophene ring leads to an increase of the oxidation potential of the monomer and to a decrease of the conductivity of the resulting polymers, even with the use of a CH2 group as spacer. Conversely, the presence of an oxygen atom directly at the 3-position of the thiophene ring, which offsets the negative withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conducting polythiophenes.

关键词： electronic effect electrochemical polymerization polythiophene polyfluorinated substituent

Highly stable Pt_(3)Ni ultralong nanowires tailored with trace Mo for the ethanol oxidation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第4期15卷 3230-3238页

作者： Mingxuan Li Yandi Cai Jinjin Zhang Haixiao Sun Zhi Li Yujie Liu Xin Zhang Xiaoping Dai Fei Gao Weiyu Song State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of PetroleumBeijing 102249China Jiangsu Key Laboratory of Vehicle Emissions Control School of the EnvironmentCenter of Modern AnalysisKey Laboratory of Mesoscopic Chemistry of MOESchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China Sinopec Zhenhai Refining&Chemical Company Ningbo 315207China

Pt_(3)Ni alloy structure is an effective strategy to accelerate ethanol oxidation reaction(EOR),while the stability in acid electrolyte is the fatal weakness and the current density still needs to be enhanced.Herein,ultralong Pt_(3)Ni nanowires tailored by trace Mo(Mo/Pt_(3)Ni NWs)were successfully synthesized by surfactant free method.The specific activity of the optimized catalyst was 2.66 mA·cm^(-2),which is approximately 2.16 and 4.6-fold that of Pt_(3)Ni NWs and commercial Pt/C catalyst,respectively.Most importantly,the Mo/Pt_(3)Ni NWs catalyst showed negligible structure degradation after 3,000 cycles(42 h)of durability test in 0.1 M HClO4 and 0.5 M ethanol,as compared to severe structural collapse and Ni dissolution for the pure Pt_(3)Ni NWs.The density functional theory(DFT)calculation also confirmed that both the surface and subsurface Mo atom could form Pt-Mo and Ni-Mo bonds with Pt and Ni,which were stronger than Pt-Ni bonds,to pin the Ni atoms in the unstable position and suppress the dissolution of surface Ni.The findings of this study indicate a promising pathway for the design and engineering of durable alloy nanocatalysts for direct ethanol fuel cell applications.

关键词： ternary Pt-based alloy one-dimensional nanowires Mo decoration electronic effect direct ethanol fuel cells

Regulation of the selective hydrogenation performance of sulfur-doped carbon-supported palladium on chloronitrobenzene

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第6期58卷 69-75页

作者： Qunfeng Zhang Bingcheng Li Yuan Zhou Deshuo Zhang Chunshan Lu Feng Feng Jinghui Lv Qingtao Wang Xiaonian Li Institute of Industrial Catalysis of Zhejiang University of Technology State Key Laboratory Breeding Base of Green Chemistry Synthesis TechnologyHangzhou 310014China

The overall performance of metal catalysts can be efficiently adjusted by modifying carbon carriers with different valence sulfur precursors.The wet impregnation technique successfully prepared carbon material carriers doped with varying sources of sulfur(Na_(2)SO_(4),NaHSO_(3),Na_(2)S·9H_(2)O).Palladium carbon catalysts doped with different sulfur precursors had been prepared with the aid of the liquid-phase reduction method of the selective hydrogenation of o-chloronitrobenzene(o-CNB)to o-chloroaniline(o-CAN).The catalyst prepared for Na_(2)S·9H_(2)O as a precursor has excellent performance,and the selectivity for o-CAN is more than 99.9%at 100%conversion.In addition,the characterization results show that with the decrease of S valence,the electronic effect between S and Pd increases,and the outer electron shift of Pd increases,which reduces the adsorption and dissociation ability of Pd to hydrogen,resulting in excellent selectivity.The effects provided a good idea for the hydrogenation of o-CNB and a different point of view on sulfur doping in a variety of hydrogenation reactions.

关键词： Catalyst Hydrogenation Selectivity Sulfur doping electronic effect