新工科背景下湖南大学应用化学专业的改革与建设

探索建立依托化学学科的"新工科"应用化学专业设置并按照"新工科"理念对现有专业进行革命性改造是十分必要的。结合我校2020应用化学专业培养计划修订及教学改革研究的实际情况,通过调整专业培养目标、课程体系、教学内容和教学模式,突出德才兼备人才培养的中心地位,以期在传承本专业腐蚀与防护的特色基础上,进一步满足新材料、新能源、高端制造、节能环保及新一代信息技术等新兴战略产业对人才的需求。还提出了应用化学新工科专业发展的方向。

调控层状双金属氢氧化物电子结构促进氧析出反应（英文）

氢气具有能量密度高、无毒、燃烧产物无环境污染等优点,是一种极具应用前景的可再生能源.目前制氢技术主要包括天然气重整制氢、光解水制氢及电解水制氢,其中天然气重整制氢存在纯度低、成本高的缺点,而光解水制氢技术尚不成熟.电解水制氢纯度高、成本低,已成为一种比较常用且成熟的制氢方法.电解水过程是指在电解池中利用电能分解水分子并释放出氢气和氧气的电化学过程,它包含两个半反应,即阳极析氧反应(OER)和阴极析氢反应(HER).在室温下驱动析氢反应与析氧反应的理论电位分别为0与1.23 V.但是,在实际电解过程中需要额外的电位(过电位)去激活和克服原始反应能垒,因此,尽可能的降低电解水的过电位是氢能广泛应用的必要条件.过渡金属化合物,特别是层状双金属氢氧化物(LDHs),由于其独特的二维层状结构和组成元素可灵活调变等特性,被认为是最具发展前景的电催化剂之一.但LDHs较差的电子导电性和较厚的板层结构极大的限制了其作为氧析出电催化剂的大规模应用.本文总结了LDHs作为OER电催化剂的研究进展,重点介绍了不同阳离子、不同阴离子、缺陷工程、各类插层阴离子和表面改性等改变对材料表面电子结构的影响机制.本文首先介绍了电解水析氧反应在不同电解液中的反应机理,讨论了析氧反应在动力学和热力学过程的主要障碍.通过对大量文献的归纳,综述了近年来通过调控LDHs的电子结构增加其活性位点数目、增强活性位点的本征活性,进而提高其OER催化性能的研究成果和最新进展,重点探讨了阳离子调控、阴离子调控、缺陷工程、插层阴离子调控和表面改性等调控方式对LDHs电催化剂OER性能的影响,总结了各种电子结构调控及其对电催化性能的影响.通过分析不同价态阳离子、阴离子对催化活性位点的电子结构影响,不同层间插层阴离子对催化剂层间距的影响,不同类型缺陷带来的微观结构和表层电子结构变化及表面改性带来的表层电子状态,亲疏水性的区别等实验现象,总结了层状过渡金属氢氧化物OER性能提升的策略.此外,本文还做了在LDHs的催化性能调控方面的挑战和展望,对未来开发和设计高效的OER电催化剂提供了崭新的思路.

Transforming Co3O4 nanosheets into porous N-doped CoxOy nanosheets with oxygen vacancies for the oxygen evolution reaction

Cobalt oxides have been widely investigated as promising replacements for noble metal-based catalysts for oxygen evolution reaction(OER). Herein, we, for the first time, have obtained porous CoxOy nanosheets with N-doping and oxygen vacancies by etching Co3O4 nanosheets with NH3 plasma. Comparing with the pristine Co3O4 nanosheets(1.79 V), the porous CoxOy nanosheets with N-doping and oxygen vacancies have a much lower potential of 1.51 V versus RHE to reach the current density of 10 mA cm-2. The obtained sample has a lower Tafel slope of 68 m V dec-1 than the pristine Co3O4 nanosheets(234 mV dec-1).The disclosed Co^2+, which is responsible for the formation of active sites(CoOOH), N-doping and oxygen vacancies, gives rise to better performance of OER.

Sulfonic groups functionalized Zr-metal organic framework for highly catalytic transfer hydrogenation of furfural to furfuryl alcohol

The highly selective catalytic transfer hydrogenation(CTH)of furfural(FF)to furfuryl alcohol(FOL)is a significant route of biomass valorization.Herein,a series microporous Zr-metal organic framework(ZrMOF)functionalized by sulfonic groups are prepared.Based on the comprehensive structural characterizations by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),N2 physisorption,Thermogravimetric(TG)and Fourier transformed infrared spectroscopy(FTIR),we find that sulfonic acid(–SO_(3)H)functional groups are tethered on the UIO-66 without affecting the structure of the framework.Systematic characterizations(NH_(3)-TPD,CO_(2)-TPD,and in-situ FTIR)demonstrate that modifying of sulfonic groups on UIO-66 results in the formation of stronger Lewis acidic-basic and Brnsted acidis sites.The cooperative role of the versatile Lewis acidic-basic and Brnsted acidic sites in 60%mol fraction of sulfonic acid-containing UIO-66(UIO-S_(0.6))retain high surface area and exhibit excellent catalytic performance of 94.7%FOL yield and 16.9 h^(-1).turnover number(TOF)under mild conditions.Kinetic experiments reveal that the activation energy of the CTH of furfural(FF)over UIO-S_(0.6) catalyst is as low as 50.8 k J mol^(-1).Besides,the hydrogen transfer mechanism is investigated through isotope labeling experiments,exhibiting that theβ-H in isopropanol is transferred to the a-C of FF by forming six-membered intermediates on the Lewis acidic-basic and Brnsted acidic sites of the UIO-S_(0.6),which is the rate-determining step in the formation of FOL.

Ultrathin defective high-entropy layered double hydroxides for electrochemical water oxidation

One of the fundamental driving forces in the materials science community is the hunt for new materials with specific properties that meet the requirements of rapidly evolving technology.

Recent Progress on Electrocatalytic Valorization of Biomass-Derived Organics

Electrocatalytic valorization of biomass derivatives can be powered by electricity generated from renewable sources such as solar and wind energy.A shift from centralized,high-temperature,and energy-intensive processes to decentralized,low-temperature conversions is achieved,which meets the requirement of sustainable energy generation.This approach provides an efficient,green,and additive-free strategy for biomass derivative valorization,in which product selectivity could be easily regulated by the applied potential and electrocatalyst utilized.However,a scale-up application is still far from being completed due to the inability of conversion rates and selectivity to meet the industrialization requirements.A better understanding of the reaction mechanism and the development of highefficiency and high-selectivity electrocatalysts are required to pave the path toward larger industrialization applications.Herein,we summarize the recent research progress in the electrocatalytic oxidation and hydrogenation of platform compounds such as furanic compounds and glycerol.In the literature,these three research areas are integrated to realize the scale-up application of the processes as mentioned above.The investigations of the mechanism are based on in situ techniques,theoretical calculations,and advanced electrocatalyst studies.Finally,the challenges and prospects in this topic are described.We expect that this review will provide the fundamental understanding and design guidelines to achieve efficient and high-selectivity catalysts and further facilitate the scale-up application of the electrocatalytic conversion of biomass derivatives.

Activity origin and alkalinity effect of electrocatalytic biomass oxidation on nickel nitride

Electro-oxidation of 5-hydroxymethylfurfural(HMFOR)is a promising green approach to realize the conversion of biomass into value-added chemicals.However,considering the complexity of the molecular structure of HMF,an in-depth understanding of the electrocatalytic behavior of HMFOR has rarely been investigated.Herein,the electrocatalytic mechanism of HMFOR on nickel nitride(Ni3 N)is elucidated by operando X-ray absorption spectroscopy(XAS),in situ Raman,quasi in situ X-ray photoelectron spectroscopy(XPS),and operando electrochemical impedance spectroscopy(EIS),respectively.The activity origin is proved to be Ni^(2+δ)N(OH)ads generated by the adsorbed hydroxyl group.Moreover,HMFOR on Ni3 N relates to a two-step reaction:Initially,the applied potential drives Ni atoms to lose electrons and adsorb OH-after 1.35 VRHE,giving rise to Ni^(2+δ)N(OH)ads with the electrophilic oxygen;then Ni^(2+δ)N(OH)ads seizes protons and electrons from HMF and leaves as H_(2) O spontaneously.Furthermore,the high electrolyte alkalinity favors the HMFOR process due to the increased active species(Ni^(2+δ)N(OH)ads)and the enhanced adsorption of HMF on the Ni3 N surface.This work could provide an in-depth understanding of the electrocatalytic mechanism of HMFOR on Ni3 N and demonstrate the alkalinity effect of the electrolyte on the electrocatalytic performance of HMFOR.

Understanding the surface segregation behavior of bimetallic CoCu toward HMF oxidation reaction

Surface segregation is ubiquitous in multi-component materials and is of great important for catalysis but little is known on the surface structure under graphene encapsulation.Here,we show that the graphene encapsulated CoCu performs well for the electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF)to2,5-furandicarboxylic acid(FDCA)with the onset potential before 1.23 VRHEand a nearly 100%selectivity of FDCA under 1.4 VRHE.From the experimental results,the unprecedented catalytic performance was attributed to local structural distortion and sub-nanometer lattice composition of the CoCu surface.We accurately show the dispersed Cu doped Co_(3)O_(4) nano-islands with a lot of edge sites on the bimetallic Co-Cu surface.While,the gradient components effectively facilitate the establishment of built-in electric field and accelerate the charge transfer.Theoretical and experimental results reveal that the surface Co and neighbouring Cu atoms in sub-nanometer lattice synergistically promote the catalysis of HMF.This work offers new insights into surface segregation in tuning the element spatial distribution for catalysis.

A Pair-Electrosynthesis for Formate at Ultra-Low Voltage Via Coupling of CO_(2) Reduction and Formaldehyde Oxidation

Formate can be synthesized electrochemically by CO_(2) reduction reaction(CO_(2)RR)or formalde-hyde oxidation reaction(FOR).The CO_(2)RR approach suffers from kinetic-sluggish oxygen evolution reac-tion at the anode.To this end,an electrochemical sys-tem combining cathodic CO_(2)RR with anodic FOR was developed,which enables the formate electrosynthesis at ultra-low voltage.Cathodic CO_(2)RR employing the BiOCl electrode in H-cell exhibited formate Faradaic efficiency(FE)higher than 90% within a wide potential range from−0.48 to−1.32 V_(RHE).In flow cell,the current density of 100 mA cm^(−2) was achieved at−0.67 V_(RHE).The anodic FOR using the Cu_(2)O electrode displayed a low onset potential of−0.13 V_(RHE) and nearly 100%formate and H_(2) selectivity from 0.05 to 0.35 V_(RHE).The CO_(2)RR and FOR were constructed in a flow cell through membrane electrode assembly for the electrosynthesis of formate,where the CO_(2)RR//FOR delivered an enhanced current density of 100 mA cm^(−2) at 0.86 V.This work provides a promising pair-electrosynthesis of value-added chemicals with high FE and low energy consumption.

调控碳材料的功函数以大幅度提升其电催化氧还原性能

氧的电催化还原反应是燃料电池装置与金属空气电池的阴极反应,具有重大的研究意义.在众多的非铂催化剂中,碳材料因其低廉的价格以及独特的物理化学性质受到了广泛的关注.自从发现氮掺杂的碳纳米阵列具有优异的氧还原活性后,不同类型的氮掺杂的碳也得到了深入研究.例如近年来兴起的由金属有机框架衍生的氮掺杂的碳材料,兼具丰富的氮位点及良好的三维结构.氮的掺杂对碳原子具有电子调控的作用,是其高氧还原活性的根本原因.本文对金属有机框架衍生的氮掺杂的碳材料进行进一步的电子结构的优化,以提升催化性能.功函是电子逸出表面所需的最少的能量,是材料的电子结构性质之一,其对氧还原反应的影响也有报道,早期以理论计算为基础,探究氧气分子在碳材料表面的解离能与氮掺杂的碳的表面功函的关系,后续则采用开尔文探针显微镜,直接测量了不同元素掺杂的碳表面功函,并建立起功函与氧还原动力学的线性关系.本文通过控制碳材料的功函来调节其电子结构.铯是一种经典的给电子物质,通过将电子注入到掺杂材料表面来降低其功函.因此,本文通过CsCO_(3)与2-甲基咪唑、Zn(NO_(3))_(2)煅烧形成铯修饰的氮掺杂碳.电镜及XRD均观察不到所得材料中铯的存在,证明碳层中无大颗粒团聚的铯物种.EDS元素分布图表明,铯在碳层中呈原子级均匀分布.Raman谱结果表明,碳的G带发生明显的位置偏移,证明其面内电子结构发生了明显的改变.XPS结果证明铯成功与氮原子配位,通过铯氮键将电子注入到碳骨架.UPS则最终显示,经过铯的修饰,碳表面功函从4.25 eV下降到3.6 eV.表面功函的降低有利于氧气分子的解离,也调节OOH^(*)中间体的吸附,使其吸附的自由能更接近最优值.材料改性后氧还原性能明显提升,起始电位达到0.91 V vs RHE,半波电位达到0.83 V vs RHE,均接近商业Pt/C催化剂.氧还原反应的动力学电流密度随功函的降低而增大,验证了前人的结论.本文提供了一个较为新颖的电子结构调控策略,为设计新的氧还原催化剂提供了新的思路.

Anodic Electrosynthesis of Amide from Alcohol and Ammonia

Amide is essential in biologically active compounds,synthetic materials,and building blocks.However,conventional amide production relies on energyintensive consumption and activating agents that modulate processes to construct the C–N bond.Herein,for the first time,we have successfully realized the formation of amides at industrial current density via the anodic coelectrolysis of alcohol and ammonia under ambient conditions.We have proved thatmodulation of the interface microenvironment concentration of nucleophile by electrolyte engineering can regulate the reaction pathways of amides rather than acetic acids.The C-N coupling strategy can be further extended to the electrosynthesis of the long-chain and aryl-ring amide with high selectivity by replacing ammonia with amine.Our work opens up a vast store of information on the utilization of biomass alcohol for high-value N-containing chemicals via an electrocatalytic C-N coupling reaction.

Defect engineering of electrocatalysts for organic synthesis

Electrocatalytic organic synthesis has attracted considerable research attention because it is an efficient and eco-friendly strategy for converting energy sources to value-added chemicals.Defect engineering is a promising strategy for regulating the electronic structure and charge density of electrocatalysts.It endows electrocatalysts with excellent physical and physicochemical properties and optimizes the adsorption energy of the reaction intermediates to reduce the kinetic barriers of the electrosynthesis reaction.Herein,the recent advances related to the use of electrocatalysts for organic synthesis with respect to defects are systematically reviewed.The roles of defects in anodic and cathodic reactions,such as the syntheses of alkanes,alkenes,alcohols,aldehydes,amides,and carboxylic acids,are reviewed.Furthermore,the relationship between the defective structure and electrocatalytic activity is discussed by combining experimental results and theoretical calculations.Finally,the challenges,opportunities,and development prospects of defective electrocatalysts are examined to promote the development of the field of electrocatalytic organic synthesis.This review is expected to help understand the vital role of defects in catalytic processes and the controllable synthesis of efficient electrocatalysts for the production of high-value chemicals.

Electro-oxidation cross-coupling of primary and secondary alcohols by constructing intermediate-enriched micro-environment

Electrocatalytic dehydrogenative cross-coupling of various alcohols in aqueous electrolytes functionalizes alcohols to form structurally diverse long-carbon-chain chemicals.However,it remains challenging to achieve the high selectivity because of the high reactivity of involved carbonyl intermediates and different oxidation rates for the alcohols.Herein,the synthesis ofα,β-unsaturated ketones from alcohols was realized by the electro-oxidation cross-coupling in aqueous solutions by a“salting-out”strategy to engineer the micro-environment at electrocatalytic reaction interfaces.Theoretical calculations and electrochemical measurements demonstrated that concentrated local intermediates could inhibit the over-oxidation of alcohols and accelerate the coupling reaction kinetics between the intermediates.This strategy can couple primary and secondary alcohols to formα,β-unsaturated carbonyl compounds with a selectivity of 87% and be easily scaled up to gram scales.This study provides an attractive strategy for broadening the diversity of organic products in electrocatalysis.

生物质平台分子的电催化氧化

Energy depletion and environmental degradation caused by the continued consumption of fossil fuels have driven the development of renewable energy conversion.As one of the main components of global renewable energy,biomass from plants and waste(the regeneration is 170 billion tons per year)has become a rich resource for biofuels and chemical industries due to its fast regeneration,degradability and non-polluting nature.

Rational design of three-phase interfaces for electrocatalysis

Gas-involving electrochemical reactions,like oxygen reduction reaction (ORR),oxygen evolution reaction (OER),and hydrogen evolution reaction (HER),are critical processes for energy-saving,environment-friendly energy conversion and storage technologies which gain increasing attention.The development of according electrocatalysts is key to boost their electrocatalytic performances.Dramatic efforts have been put into the development of advanced electrocatalysts to overcome sluggish kinetics.On the other hand,the electrode interfaces-architecture construction plays an equally important role for practical applications because these imperative electrode reactions generally proceed at triple-phase interfaces of gas,liquid electrolyte,and solid electrocatalyst.A desirable architecture should facilitate the complicate reactions occur at the triple-phase interfaces,which including mass diffusion,surface reaction and electron transfer.In this review,we will summarize some design principles and synthetic strategies for optimizing triple-phase interfaces of gas-involving electrocatalysis systematically,based on the electrode reaction process at the three-phase interfaces.It can be divided into three main optimization directions:exposure of active sites,promotion of mass diffusion and acceleration of electron transfer.Furthermore,we especially highlight several remarkable works with comprehensive optimization about specific energy conversion devices,including metal-air batteries,fuel cells,and water-splitting devices are demonstrated with superb efficiency.In the last section,the perspectives and challenges in the future are proposed.

Single-crystalline layered double hydroxides with rich defects and hierarchical structure by mild reduction for enhancing the oxygen evolution reaction

The oxygen evolution reaction(OER)with sluggish reaction kinetics and large overpotential is the critical reaction in water splitting that is promising for energy storage and conversion.Layered double hydroxides(LDHs),due to their unique lamellar structure and flexibility of chemical component,are very competing material candidates for OER.Herein,the morphology structure and the electronic structure of LDHs were simultaneously tuned to improve the OER catalytic activity by mild solvothermal reduction using ethylene glycol.The increased surface area,the introduction of oxygen vacancies and the construction of hierarchical structure greatly enhanced the electro-catalytic activity of LDHs for OER.The as-prepared LDHs showed a lower over-potential as low as 276 mV at a current density of 10 mA cm-2,and a small Tafel slope of 40.3 mV dec-1 accompanied with good stability.This work provides an efficient way to the design and optimization of advanced catalysts in the future.

Low-temperature plasma technology for electrocatalysis

Electrochemical reactions were widely used in energy storage and conversion devices. The development of low-cost, highly efficient and stable electrocatalyst is essential to a large-scale application of energy storage and conversion devices. Recently, emerging plasma technology has been employed as one of the practical ways to synthesize and modify electrocatalysts due to its unique property. In this review, we summarized the latest applications of plasma in energy storage and conversion, including using it as the preparation and modification technology of the various electrocatalysts and the usage of it as the synthesis technology directly. Firstly, we presented the definition and types of plasma reactors and their respective characteristics. Then, these applications of plasma technology in many essential electrode reactions including carbon dioxide reduction reaction(CO_2RR), nitrogen fixation, oxygen reduction reaction(ORR), oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) were introduced.Finally, the challenges and outlook of plasma technology in energy storage and conversion were summarized, and the solutions and prospected its development in the future were present. Through reviewing the related aspects, readers can have a deeper understanding of the application prospects of plasma in electrocatalysis.

Hierarchically nanostructured Ni O-Co3O4 with rich interface defects for the electro-oxidation of 5-hydroxymethylfurfural

Ni-based electrocatalysts with strong redox abilities are active for the electrochemical oxidation of 5-hydroxymethylfurfural(HMF). Interface engineering is an efficient way to modulate the electronic structure, tune the intermediate adsorption, and expose more active sites. Herein, we increased the concentration of interfacial sites with rich defects in a 3D hierarchical nanostructured NiO-Co3O4 electrocatalyst and investigated its catalytic performance for HMF electro-oxidation. The interface effect created abundant cation vacancies, modulated the electronic properties of Co and Ni atoms, and raised the oxidation state of Ni species. The NiO-Co3O4 catalysts show superb HMF oxidation activities with a low onset potential of 1.28 VRHE.Meanwhile, in-situ surface-selective vibrational spectroscopy of sum-frequency generation was performed to study the reaction pathway during the oxidation process on the electrocatalysts. The current study offers an efficient way to create cation vacancies and proves the decisive role of cation vacancies in catalyzing the HMF electro-oxidation.

In Situ Exfoliation and Pt Deposition of Antimonene for Formic Acid Oxidation via a Predominant Dehydrogenation Pathway

Direct formic acid fuel cell(DFAFC)has been considered as a promising energy conversion device for stationary and mobile applications.Advanced platinum(Pt)electrocatalysts for formic acid oxidation reaction(FAOR)are critical for DFAFC.However,the oxidation of formic acid on Pt catalysts often occurs via a dual pathway mechanism,which hinders the catalytic activity owing to the CO poisoning.Herein,we directly exfoliate bulk antimony to 2D antimonene(Sb)and in situ load Pt nanoparticles onto antimonene sheets with the assistance of ethylenediamine.According to the Bader charge analysis,the charge transfer from antimonene to Pt occurs,confirming the electronic interaction between Pt and Sb.Interestingly,antimonene,as a cocatalyst,alters the oxidation pathway for FAOR over Pt catalyst and makes FAOR follow the more efficient dehydrogenation pathway.The density functional theory(DFT)calculation demonstrates that antimonene can activate Pt to be a lower oxidative state and facilitate the oxidation of HCOOH into CO_(2) via a direct pathway,resulting in a weakened intermediate binding strength and better CO tolerance for FAOR.The specific activity of FAOR on Pt/Sb is 4.5 times,and the mass activity is 2.6 times higher than the conventional Pt/C.

Interlayer ligand engineering of β-Ni(OH)2 for oxygen evolution reaction

Oxygen evolution reaction(OER)is a bottleneck process for many electrochemical devices due to the sluggish kinetics,for which advanced electrocatalysts should be carefully designed.Nickle-based materials have been extensively studied to catalyze OER.However,their performances are still below the expectation and the active sites are often controversial.Herein,we have successfully modulated the electronic and surface properties of layeredβ-Ni(OH)2 by the interlayer ligand engineering,aiming to design novel efficient electrocatalysts and unveil the catalysis mechanism.By one-step solvothermal reaction,alkoxyl substitutedβ-Ni(OH)2 with variable interlayer distances is obtained,and the ethoxyl substituted one(NiEt)shows great potential for efficient OER.With the assistance of powder X-ray diffraction and crystalline structure computational simulation,the formula of alkoxyl substitutedβ-Ni(OH)2 are determined.Operando X-ray absorption spectroscopy studies combined with ex-situ analyses revealed that the critical active species of NiEt is formed via hydroxylation and subsequent de-protonation,with high valent Niδ+(3<δ≤3.66).The corresponding catalytic reaction pathway and mechanism are proposed.