Chalcogen heteroatoms doped nickel-nitrogen-carbon single-atom catalysts with asymmetric coordination for efficient electrochemical CO_(2)reduction

The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2)reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N4-C)configuration to obtain Ni-X-N3-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N3-C(X:S,Se,and Te)SACs,Ni-Se-N3-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98%at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2)battery integrated with Ni-Se-N3-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm-2 and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N4-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)RR.Especially,for Ni-Se-N3-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of*COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction.

Regio-and Diasteroselectivity of Rhodium-catalyzed Ring Opening Reaction of Oxabenzonorbornadienes with Heteroatom Nucleophiles

A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.

The Studies of Rhodium-catalyzed Ring Opening Reaction of N-Boc-azabenzonorbornadiene with Heteroatom Nucleophiles

A rhodium-catalyzed ring opening reaction of N-Boc-azabenzonorbornadiene with heteroatom nucleophiles was described. Piperidine and piperazine＇s derivatives were nucleophiles in this reaction. The yields of the products 2a-f are good and the regioselectivity are excellent.

Heteroatom-Induced Accelerated Kinetics on Nickel Selenide for Highly Efficient Hydrazine-Assisted Water Splitting and Zn-Hydrazine Battery

Hydrazine-assisted water electrolysis is a promising energy conversion technology for highly efficient hydrogen production.Rational design of bifunctional electrocatalysts,which can simultaneously accelerate hydrogen evolution reaction(HER)/hydrazine oxidation reaction(HzOR)kinetics,is the key step.Herein,we demonstrate the development of ultrathin P/Fe co-doped NiSe_(2) nanosheets supported on modified Ni foam(P/Fe-NiSe_(2)) synthesized through a facile electrodeposition process and subsequent heat treatment.Based on electrochemical measurements,characterizations,and density functional theory calculations,a favorable“2+2”reaction mechanism with a two-step HER process and a two-step HzOR step was fully proved and the specific effect of P doping on HzOR kinetics was investigated.P/Fe-NiSe_(2) thus yields an impressive electrocatalytic performance,delivering a high current density of 100 mA cm^(−2) with potentials of−168 and 200 mV for HER and HzOR,respectively.Additionally,P/Fe-NiSe_(2) can work efficiently for hydrazine-assisted water electrolysis and Zn-Hydrazine(Zn-Hz)battery,making it promising for practical application.

Defect Engineering of Disordered Carbon Anodes with Ultra-High Heteroatom Doping Through a Supermolecule-Mediated Strategy for Potassium-Ion Hybrid Capacitors

Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities.Nevertheless,most lignocellulose biomasses lack heteroatoms,making it a challenge to design highly heteroatom-doped carbons(>10 at%).Herein,we report a new preparation strategy for amorphous carbon anodes.Nitrogen/sulfur co-doped lignin-derived porous carbons(NSLPC)with ultra-high nitrogen doping levels(21.6 at%of N and 0.8 at%of S)from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy.This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product,which induces the formation of high heteroatom doping in the obtained NSLPC.This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+and improved kinetics.The NSLPC anode delivered a high reversible capacity of 419 mAh g^(-1)and superior cycling stability(capacity retention of 96.6%at 1 A g^(-1)for 1000 cycles).Potassiumion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability(91%capacity retention for 2000 cycles)and a high energy density of 71 Wh kg^(-1)at a power density of 92 W kg^(-1).

Heteroatom dopant strategy triggered high-potential plateau to non-graphitized carbon with highly disordered microstructure for high-performance sodium ion storage

Non-graphitized carbon(NGC)has been extensively utilized as carbonaceous anode in sodium-ion batteries(SIBs).However,more optimization to achieve competitive capacity and stability is still challenging for SIBs.In the study,the dopant strategy is utilized to construct nitrogen/sulfur-doped non-graphitized carbon(N-NGC or S-NGC)shell decorated on three-dimensional graphene foam(GF)as a self-support electrode.The highly disordered microstructures of heteroatom doped carbons are produced by applying a low-temperature pyrolysis treatment to precursors containing nitrogen and sulfur.The DFT calculations of Na-ion adsorption energies at diverse heteroatom sites show marginal-S,pyrrolic N and pyridinic N with more intensive Na-ion adsorption ability than middle-S,C=O and pristine carbon.The N-NGC with dominant small graphitic regions delivers adsorption ability to Na-ion,while the S-NGC with significant single carbon lattice stripes demonstrates redox reaction with Na-ion.Evidently,in comparison with only adsorption-driven slope regions at high potential for N-NGC,the redox reaction-generated potentialplateau enables non-graphitized S-NGC superior discharge/charge capacity and cycle-stability in the slope region.This work could provide deep insight into the rational design of non-graphitized carbon with rich microstructure and composition.

Heteroatomic Modification of Solid-Waste-Based Mesoporous Carbon for Volatile Organic Compound Adsorption

Solid-waste-based activated carbon(AC)was utilized as a carbon source to synthesize a series of carbon-based functional material RAC-X(X=P and S,where P and S denote phosphoric and sulfuric acids,respectively).The toluene adsorption capacities of the regeneration AC(RAC)samples can be significantly improved by adopting the heteroatomic modification strategy.RAC-P and RAC-S have the same specific surface area(1156 m^(2)/g)and similar porous structures.However,they have different toluene adsorption capacities,with 316.22 mg/g for RAC-P and 460.12 mg/g for RAC-S,which are 1.6 and 2.4 times greater than that for RAC.The X-ray photoelectron spectroscopy measurements showed that the increase in the amount ofπ–π^(2)chemical bond over the AC surface results in the improvement of the toluene adsorption performance.The density functional theory results showed that the S-containing functional groups loaded near the defect sites of RAC-S promote toluene adsorption.Moreover,reusability tests showed that RAC-S still retains 86%of its adsorption activity after four consecutive adsorption–desorption experiments.This indicates that the heteroatomic modification method affords excellent toluene adsorption performance and recycling practicability,which not only is beneficial for achieving the rational utilization of solid waste resources but also provides a practical method for the efficient elimination of volatile organic compounds.

An ensemble learning classifier to discover arsenene catalysts with implanted heteroatoms for hydrogen evolution reaction

Accurate regulation of two-dimensional materials has become an effective strategy to develop a wide range of catalytic applications.The introduction of heterogeneous components has a significant impact on the performance of materials,which makes it difficult to discover and understand the structure-property relationships at the atomic level.Here,we developed a novel and efficient ensemble learning classifier with synthetic minority oversampling technique(SMOTE) to discover all possible arsenene catalysts with implanted heteroatoms for hydrogen evolution reaction(HER).A total of 850 doped arsenenes were collected as a database and 140 modified arsenene materials with different doping atoms and doping sites were identified as promising candidate catalysts for HER,with a machine learning prediction accuracy of 81%.Based on the results of machine learning,we proposed 13 low-cost and easily synthesized two-dimensional Fe-doped arsenene catalytic materials that are expected to contribute to high-efficient HER.The proposed ensemble method achieved high prediction accuracy,but millions of times faster to predict Gibbs free energies and only required a small amount of data.This study indicates that the presented ensemble learning classifier is capable of screening high-efficient catalysts,and can be further extended to predict other two-dimensional catalysts with delicate regulation.

不同馏分油分级分质加工中萃取技术研究进展

解决传统燃料过剩、开发绿色高效低耗的油品加工技术是双碳背景下的必然趋势。发展分子炼油理念下的变革性加工技术,实现从“馏分加工”到“组分加工”,是节能降耗、物尽其用的重要思路,其中组分的高效分离是实践分子炼油理念、实现精细化加工的重中之重。详细介绍了我国各种馏分油的化学组成的分布规律以及现有溶剂萃取技术分离芳烃、烷烃和杂原子化合物等组分的研究现状,讨论了各类油品由于组成差异而导致不同的分离难点,旨在提出未来研究的切入点和有价值的研究方向。

新型吡咯[3,4-b]喹啉-1-酮衍生物的简便合成

报道以2-氯甲基喹啉-3-羧酸乙酯为底物,通过与各种芳胺及脂肪胺类化合物在乙醇-乙酸(10:1,v/v)的混合溶剂体系中,经连续的亲核取代和分子内的亲核环化反应过程,一步合成了一系列新型的N-取代-2,3-二氢-1H-吡咯[3,4-b]喹啉-1-酮类化合物.该合成方法具有实验操作简便,反应条件温和,后处理简单和产率高等优点,具有很好的实际应用价值.

碳基复合催化剂降解有机污染物研究进展

过硫酸氢盐高级氧化工艺是降解各种有机污染物的有效治理方法,高效、经济、环保的过硫酸氢盐催化剂是现阶段的研究热点。碳基催化剂作为环境友好、稳定性高的绿色催化材料,具有强吸附能力并且能够有效防止有毒金属离子的浸出和二次污染。本文阐述了碳基材料活化过硫酸盐的三种机理:自由基、非自由基以及两种机制并存的途径。详述了单一过渡金属和双过渡金属、非金属杂原子负载在碳基材料上形成的复合催化剂和生物质材料催化剂活化过硫酸氢盐对有机污染物的降解效果,对碳基催化剂用于活化过硫酸氢盐降解废水中有机污染物的研究方向进行了展望。

一种Voxelotor衍生物的合成

以沃塞洛托(Voxelotor,2)为原料,通过亲核加成、氧化等2步反应,得到Voxelotor衍生物2-羟基-6-((2-(1-异丙基-1H-吡唑-5-基)吡啶-3-基)甲氧基)苯基丙-2-烯-1-酮(1),通过1HNMR和ESI-MS对中间体4及目标化合物1的结构进行了表征,并对中间体4及目标化合物1的合成条件进行了优化。结果表明,最佳亲核加成反应条件为:物料比n(乙烯基溴化镁)∶n(2)为2.0∶1、反应时间为2 h,在此条件下,中间体4收率为62%;最佳氧化反应条件为:反应溶剂为二氯甲烷、氧化剂2-碘酰基苯甲酸(IBX)用量n(IBX)∶n(4)为1.2∶1、反应时间为22 h,在此条件下,目标化合物1收率为54%。

昭通褐煤氨解可溶化转化及热溶物中氧和氮的赋存形态

褐煤碳含量高且富含氧、氮等杂原子,是制备炭材料的重要原料。但由于褐煤可溶有机碳含量低,杂原子分配无规律,导致以褐煤为原料制备炭材料面临诸多挑战。因此,亟需实现褐煤的可溶化转化。本研究以氨水为溶剂,旨在温和条件下,同步实现昭通褐煤的可溶化和褐煤热溶物中氧和氮的调控。实验结果表明,在氨水质量分数15%、温度160℃条件下反应3 h,热溶物收率最高为76.66%,昭通褐煤表现出良好的热溶效果。基于对热溶物的表征和分析,发现氨解在一定程度上改变了煤中的大分子结构,表现为氨基与羟基置换,或与部分羧基、羰基直接反应生成有机态氮。对比发现,原煤中氮元素赋存形态以季氮和吡咯氮为主,而可溶物中氮元素赋存形态以氨基氮和吡啶氮为主,表明褐煤氨解热溶过程产生了氨基或酰胺基。

杂原子掺杂石墨烯的制备及应用研究进展

目的综述杂原子掺杂石墨烯的研究进展,对杂原子掺杂石墨烯的未来研究方向进行展望,旨在为杂原子掺杂石墨烯的制备及应用提供参考。方法总结和分析了杂原子掺杂石墨烯的制备方法和潜在应用领域,对比了各种杂原子掺杂对石墨烯电子性质的影响,突出不同元素掺杂的独特性和效果。结果杂原子掺杂不仅提高了石墨烯的电导率和力学强度,还增加了它在特定应用中的稳定性和效率。结论杂原子掺杂石墨烯的发展前景广阔,有望在能源存储、生物医药、环境保护、传感器及印刷包装等领域实现重要突破。

低温等离子体技术在碳材料表面改性中的应用

叙述了低温等离子体技术的基本原理,其次分别介绍了该技术在表面改性碳纳米管、石墨材料、氧化石墨烯以及新型多孔碳材料中的应用,列举了国内外该领域的部分研究成果,讨论了低温等离子体表面改性碳材料面临的挑战并对其未来发展进行了展望。

A robust & weak-nucleophilicity electrocatalyst with an inert response for chlorine ion oxidation in large-current seawater electrolysis

Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.

杂原子[Ga]AlY分子筛吸附脱除模拟柴油中的氮化物

采用液-固相同晶取代法制备了杂原子[Ga] AlY分子筛,并利用X射线衍射(XRD)和红外光谱(FT-IR)等手段对其进行了表征。将[Ga] AlY分子筛用于模拟柴油中碱性氮化物苯胺、吡啶或喹啉的静态吸附脱氮实验,采用Materials Studio软件对[Ga] AlY分子筛吸附脱氮机理进行了分子模拟计算研究。结果表明,在模拟柴油用量15 mL时,[Ga] AlY分子筛较适宜的吸附脱氮条件为:室温,分子筛用量0.2 g、吸附时间20 min。模拟计算的吸附能、d距离及吸附等温线结果表明,[Ga] AlY分子筛吸附三种碱性氮化物的强弱顺序均为:吡啶>苯胺>喹啉,较符合Freundlich模型,这也与实验结果一致。吸附热力学和吸附动力学研究结果表明,苯胺的吸附反应是自发进行的吸附熵增过程,吡啶和喹啉为吸附熵减过程,三者的吸附均为放热过程。在303 K条件下,喹啉的吸附过程较符合准一级动力学模型,吡啶和苯胺的程较符合准二级动力学模型。

石墨烯基材料在电磁屏蔽领域的研究进展

通信技术在为人类的生活带来便利的同时,其产生的电磁辐射对社会安全、人体健康产生的危害也受到了社会各界的广泛关注,宽屏蔽范围、高吸收效率和高稳定性的电磁屏蔽材料逐渐成为研究热点。石墨烯是一种导电性高、比表面积大且可调控性高的轻质材料,可有效实现电磁衰减,保护精密电子设备和人体健康,在电磁屏蔽领域具有广阔的应用前景。本综述从电磁屏蔽的基本原理与石墨烯基材料的结构特性角度,阐述了石墨烯及其衍生物的电磁屏蔽特点,总结了结构调控以及表面异质化、复合化策略在电磁屏蔽领域的应用。结构调控有利于提高石墨烯基材料对电磁波的吸收损耗和多重反射损耗;表面异质化和复合化策略有利于提高石墨烯基材料的界面极化和磁特性,从而加强对电磁波的吸收损耗和磁损耗。总结了石墨烯基电磁屏蔽材料的改性方法,旨在为开发新一代绿色、轻薄、高屏蔽带宽的电磁屏蔽材料提供启发,指明石墨烯基电磁屏蔽材料的未来发展方向。

4-(氨甲基)-N-甲氧基苯脒合成研究

本研究报道一种结构新颖的苯脒化合物(1)的合成。以1,4-二溴苯(2)为原料,首先经历氰基取代反应得到4-溴苯腈(3),然后,中间体(3)与甲基硼酸(4)发生Suzuki偶联反应得到4-甲基苯腈(5),中间体(5)再发生NBS溴代反应得到4-(溴甲基)苯腈(6),随后,中间体(6)与双(叔丁氧羰基)胺发生亲核取代反应得到N,N-二(叔丁氧羰基)-4-氰基苯甲胺(7),中间体(7)再与甲氧基胺盐酸盐(8)发生亲核加成反应,得到N,N-二(叔丁氧羰基)-4-(N'-甲氧基脒基)苯甲胺(9),最后,中间体(9)在酸性条件下脱除Boc保护基,得到产物4-(氨甲基)-N-甲氧基苯脒盐酸盐(1)。中间体及产物结构通过~1H NMR和ESI-MS进行表征,其中产物结构进一步通过^(13)C NMR表征。

溶剂萃取-亲核反应脱除塑料热解油中有机氯

研究了溶剂萃取-亲核反应脱氯,考察了反应溶剂类型、亲核试剂类型和用量、反应溶剂与油品质量比、油品中其他组分等因素对亲核反应脱氯效果的影响,分析了溶剂萃取-亲核反应脱氯的速控步骤,鉴定了不同氯化物的反应产物。实验结果表明,三乙二醇、二乙二醇、乙二醇、甘油均可有效萃取有机氯,对亲核试剂有较高的溶解性,可促进有机氯和亲核试剂的接触和反应,且黏度低的反应溶剂更有利于亲核反应脱氯,其中乙二醇的综合性能最好;有机氯的萃取是溶剂萃取-亲核反应脱氯的速控步骤;在研究的各种亲核试剂中,NaHS的亲核性最强,当反应温度为150℃、n(NaHS)∶n(Cl)=4、m(乙二醇)∶m(油品)=1时,真实塑料热解油脱氯率达到95.8%;伯氯代烃和仲氯代烃的反应活性显著高于氯代芳烃。