CO_(2) electrolysis to formic acid for carbon neutralization

To avoid carbonate precipitation for CO_(2) electrolysis,developing CO_(2) conversion in an acid electrolyte is viewed as an ultimately challenging technology.In Nature,Xia et al.recently explored a proton-exchange membrane system for reducing CO_(2) to formic acid with a Pb±Pb SO_(4) composite catalyst derived from waste lead-acid batteries based on the lattice carbon activation mechanism.Up to 93%Faradaic efficiency was realized when formic acid was produced by this technology.

Amorphous core-shell NiMoP@CuNWs rod-like structure with hydrophilicity feature for efficient hydrogen production in neutral media

Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.

Ultralow charge-discharge voltage gap of 0.05 V in sunlight-responsive neutral aqueous Zn-air battery

Rechargeable neutral aqueous zinc-air batteries(ZABs)are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs.However,the neutral ZABs normally possess poor oxygen evolution reactions(OERs)and oxygen reduction reactions performance,resulting in a large charge–discharge voltage gap and low round-trip efficiency.Herein,we demonstrate a sunlight-assisted strategy for achieving an ultralow voltage gap of 0.05 V in neutral ZABs by using the FeOOH-decorated BiVO4(Fe-BiVO4)as an oxygen catalyst.Under sunlight,the electrons move from the valence band(VB)of Fe-BiVO_(4) to the conduction band producing holes in VB to promote the OER process and hence reduce the overpotential.Meanwhile,the photopotential generated by the Fe-BiVO_(4) compensates a part of the charging potential of neutral ZABs.Accordingly,the energy loss of the battery could be compensated via solar energy,leading to a record-low gap of 0.05 V between the charge and discharge voltage with a high round-trip efficiency of 94%.This work offers a simple but efficient pathway for solar-energy utilization in storage devices,further guiding the design of high energy efficiency of neutral aqueous ZABs.

Striking Stabilization Effect of Spinel Cobalt Oxide Oxygen Evolution Electrocatalysts in Neutral pH by Dual-Sites Iron Incorporation

Developing stable and efficient nonprecious-metal-based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical systems.Particularly,cobalt-based spinels have drawn a considerable amount of attention but most of them operate in alkali solutions.However,the frequently studied Co-Fe spinel system never exhibits appreciable stability in nonbasic conditions,not to mention attract further investigation on its key structural motif and transition states for activity loss.Herein,we report exceptional stable Co-Fe spinel oxygen evolution catalysts(~30%Fe is optimal)in a neutral electrolyte,owing to its unique metal ion arrangements in the crystal lattice.The introduced iron content enters both the octahedral and tetrahedral sites of the spinel as Fe^(2+)and Fe^(3+)(with Co ions having mixed distribution as well).Combining density functional theory calculations,we find that the introduction of Fe to Co_(3)O_(4)lowers the covalency of metal-oxygen bonds and can help suppress the oxidation of Co^(2+/3+)and 0^(2-).It implies that the Co-Fe spinel will have minor surface reconstruction and less lattice oxygen loss during the oxygen evolution reaction process in comparison with Co_(3)O_(4)and hence show much better stability.These findings suggest that there is still much chance for the spinel structures,especially using reasonable sublattices engineering via multimetal doping to develop advanced oxygen evolution catalysts.

A critical assessment of the roles of water molecules and solvated ions in acid-base-catalyzed reactions at solid-water interfaces

Solid-aqueous interfaces and phenomena occurring at those interfaces are ubiquitously found in a plethora of chemical systems.When it comes to heterogeneous catalysis,however,our understanding of chemical transformations at solid-aqueous interfaces is relatively limited and primitive.This review phenomenologically describes a selection of water-engendered effects on the catalytic behavior for several prototypical acid-base-catalyzed reactions over solid catalysts,and critically assesses the general and special roles of water molecules,structural moieties derived from water,and ionic species that are dissolved in it,with an aim to extract novel concepts and principles that underpin heterogeneous acid-base catalysis in the aqueous phase.For alcohol dehydration catalyzed by solid Bronsted acids,rate inhibition by water is most typically related to the decrease in the acid strength and/or the preferential solvation of adsorbed species over the transition state as water molecules progressively solvate the acid site and form extended networks wherein protons are mobilized.Water also inhibits dehydration kinetics over most Lewis acid-base catalysts by competitive adsorption,but a few scattered reports reveal substantial rate enhancements due to the conversion of Lewis acid sites to Brønsted acid sites with higher catalytic activities upon the introduction of water.For aldol condensation on catalysts exposing Lewis acid-base pairs,the addition of water is generally observed to enhance the rate when C–C coupling is rate-limiting,but may result in rate inhibition by site-blocking when the initial unimolecular deprotonation is rate-limiting.Water can also promote aldol condensation on Brønsted acidic catalysts by facilitating inter-site communication between acid sites through hydrogen-bonding interactions.For metallozeolite-catalyzed sugar isomerization in aqueous media,the nucleation and networking of intrapore waters regulated by hydrophilic entities causes characteristic enthalpy-entropy tradeoffs as these water moieties interact with kinetically relevant hydride transfer transition states.The discussed examples collectively highlight the utmost importance of hydrogen-bonding interactions and ionization of covalently bonded surface moieties as the main factors underlying the uniqueness of water-mediated interfacial acid-base chemistries and the associated solvation effects in the aqueous phase or in the presence of water.A perspective is also provided for future research in this vibrant field.

Acid-base cooperativity of heterogeneous catalyst containing acidic framework and sterically hindered base for aldol condensation

A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesized by postgrafting of 1,5,7- triazabicyclo[4.4.0] dec-5-ene （TBD, a sterically hindered organic base） onto AI-MCM-41 molecular sieve. 2009 Xiao Bing Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Ultralow-voltage hydrogen production and simultaneous Rhodamine B beneficiation in neutral wastewater

Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can improve the energy conversion efficiency.Since iron corrodes easily and even self-corrodes to form magnetic iron oxide species and generate corrosion currents,a novel strategy to integrate the hydrogen evolution reaction(HER)with waste Fe upgrading reaction(FUR)is proposed and demonstrated for energy-efficient hydrogen production in neutral media.The heterostructured MoSe_(2)/MoO_(2) grown on carbon cloth(MSM/CC)shows superior HER performance to that of commercial Pt/C at high current densities.By replacing conventional OER with FUR,the potential required to afford the anodic current density of 10 m A cm^(-2)decreases by 95%.The HER/FUR overall reaction shows an ultralow voltage of 0.68 V for 10 m A cm^(-2)with a power equivalent of 2.69 k Wh per m^(3)H_(2).Additionally,the Fe species formed at the anode extract the Rhodamine B(Rh B)pollutant by flocculation and also produce nanosized magnetic powder and beneficiated Rh B for value-adding applications.This work demonstrates both energy-saving hydrogen production and pollutant recycling without carbon emission by a single system and reveals a new direction to integrate hydrogen production with environmental recovery to achieve carbon neutrality.

Engineering thermochemistry:The science critical for the paradigm shift toward carbon neutrality

The global shift toward carbon neutrality,driven by growing concerns about climate change,requires collaborative efforts.While cleaner energy and carbon capture are crucial,addressing some high-carbon-emission industrial processes that significantly and disproportionally contribute to our carbon footprint is more important than ever.Analysis reveals that over 90%of total carbon emissions from human activities are attributed to a few super-emitting thermochemical processes.We urgently need breakthrough technologies and transformative alternatives to combat this excess of carbon dioxide emissions effectively.Engineering Thermochemistry is the scientific discipline that offers both scientifically sound and practical solutions to the pressing carbon neutrality challenges.

Triphenylmethanol and Tris(2-(hydroxymethyl)phenol) Derivatives: Synthesis and Application as Indicators for Acid-Base Volumetric Titration

Polyphenols are naturally occurring compounds found largely in fruits, vegetables, cereals and beverages. Currently, there is much interest in the potential health benefits of dietary plant polyphenols as antioxidants. The effect of polyphenols on human cancer cells is most often protective and induces a reduction in the number of tumors or rate of growth. During our course of study on anticancer prodrugs, twelve triphenylmethanol and one tris(2-(hydroxymethyl) phenol derivatives were synthesized as a carrier of several drugs with optimized lipophilicity. Besides application of these compounds as a foundation for anticancer drug delivery systems, these compounds were evaluated as indicators for the acid-base volumetric titration of a standard solution of hydrochloric acid with a standard solution of sodium hydroxide. The experiments indicated a moderate-to-sharp color transition of the solutions near the neutralization point for most indicators. These indicators may have potential applications for acid-base titrations in a narrow range.

脱水耦合逆水气变换制一氧化碳过程研究

逆水气变换制是CO为CO_(2)加氢二步法合成甲醇过程中的第一步。本文在逆水气变换反应过程引入脱水耦合反应,突破该反应在低温下的平衡限制。本文考察了脱水剂性能、脱水剂含量、H2与CO进料比等对该反应的影响,证明添加20%的脱水剂即可至少提高商用催化剂低温(220~330℃)活性4~5倍,并获得远超平衡限制的CO_(2)转化率。

物理化学课程思政案例——电化学助力“碳达峰碳中和”

以习近平主席在第七十五届联合国大会上提出的“碳达峰碳中和”目标为载体,切入“碳达峰碳中和”与电化学的关联点,实现思政元素与专业知识的自然融合。结合电催化还原CO_(2)的科研前沿,引导学生分析电化学还原CO_(2)的原理、特征、反应效率及面临的挑战;从课程内容的拓展及与思政元素的融合等方面阐述融合教育的实施方案。以团队合作学习的方式及通过课后阅读文献、写报告、课堂展示的形式对文献报道体系的产物选择性、催化剂稳定性、法拉第效率等进行评价,并对其挑战性问题进行思考,完善学生的知识体系,实现对教材内容的拓展和深化,达到课程内容与前沿研究、工业应用相结合的培养目标,培养学生的社会责任感和时代使命感,从而实现价值引领。

新兴交叉学科“工程热化学”助力实现“碳中和”目标

我国90%以上的碳排放来自有机碳资源和碳酸盐矿物的利用,而这些资源在短期内无法替代。因此,应对“碳中和”挑战的最有效策略是减少这些热化学反应(热诱发/热驱动的化学反应)相关的“超级排放源”。工程热化学(Engineering thermochemistry,ETC)是一门新兴交叉学科,关注热化学反应及其工程化科学与技术。该文介绍了工程热化学的定义、科学内涵,回顾了工程热化学形成与发展的详细历程,根据其提供的科学方法和原理,分析了可指导且有效的大规模碳减排、碳替代、碳循环途径,展示了工程热化学减少数十亿吨碳排放的方法和依据。

热化学反应工程科学与技术发展与展望

“热”诱发、“热”驱动的热化学反应是人类最早认识的化学反应,占据工业化学反应的绝大部分,是能源转化、资源加工、循环经济等的重要反应,涉及发电、供热、冶金、建材、废物消纳等重大工业行业,这些行业是与人类活动相关的CO_(2)排放源的主体,在总碳排放中占比90%以上。在“双碳”目标下,热化学反应科学和技术的创新发展凸显更加特殊和重要的作用,其重要内容之一就是“支撑热化学反应工程化”的科学与技术,即“热化学反应工程”。针对“热”诱导、“热”驱动的化学反应,本文深入归纳和分析其相关科学和技术从古至今的发展特点,凝练形成了五个具有不同科学与技术特点的典型发展时期。总结典型热化学反应相关行业的重要科学与技术的发展及其对社会进步的贡献和影响,阐明“双碳”战略背景下“热化学反应工程”的科技创新机遇和贡献“碳中和”的潜力,揭示了通过碳减排、碳替代和碳循环的技术创新和应用推广,可有效推动我国各种“超级碳排放源”的碳排放强度和碳排放量的大幅降低,实现年60亿吨级二氧化碳的消减。

电荷极化光催化剂光转化二氧化碳制多碳化学品的研究进展

二氧化碳(CO_(2))光合成高附加值多碳化学品是缓解温室效应和能源危机的极具前景的绿色发展新技术。设计具有电荷极化活性位点的光催化剂能够有效降低C-C偶联反应能垒,进而提高光合成多碳化学品催化选择性和活性。本文综述了光催化CO_(2)还原制C_(2)化学品的相关研究,深入研究电荷不对称位点构筑的主要策略,阐明微观层面上电荷极化效应对C_(2)产物活性和选择性的影响机制,总结出极具前景的高效光催化剂的设计与开发思路,为光催化技术的实际应用提供重要的理论和实践指导。展望未来,应更加注重催化剂在原子层面上的精准调控,开发出更高效、更专一的多碳产物制备系统,助力能源产业结构的低碳转型。

3d过渡金属单原子掺杂石墨烯缺陷电催化还原CO_(2)的第一性原理研究

将CO_(2)高效转化为有价值的化学品(如CO和HCOOH等)是缓解环境问题、实现碳中和的重要措施。然而CO_(2)还原反应(CO_(2)RR)有着产物多样和路径复杂的特点,再加上目前难以确定影响CO_(2)RR活性的真正因素,使得设计对特定产物有高选择性和高活性的催化剂十分具有挑战性。本研究从第一性原理出发,系统研究了3d过渡金属单原子掺杂石墨烯单个空位(TM@CSV)和双空位(TM@CDV)电催化还原CO_(2)的潜力,具体涵盖基底的稳定性、中间产物热力学吸附以及与之竞争的析氢反应(HER)。通过对Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu和Zn掺杂石墨烯缺陷后形成的20种催化剂进行筛选,发现Sc原子掺杂石墨烯单个空位的Sc@CSV和Sc、Ti原子掺杂石墨烯双空位的Sc@CDV和Ti@CDV同时具备吸附CO_(2)分子和抑制HER的能力。其中Sc@CDV对HCOOH表现出最佳的活性和选择性,速率决定步骤的吉布斯自由能差仅为0.96 eV。最后,通过电子结构分析进一步揭示了Sc@CDV优于其他催化剂的原因是Sc@CDV调整了费米能级附近的活性电子态,从而实现对CO_(2)的高效还原。

丙酰氯废液中和处置技术

为了降低酸度很高、腐蚀性很强的丙酰氯废液的处置难度,增加后端处置的安全和效率。先用去离子水稀释丙酰氯废液,而后采用质量分数为3%的NaOH溶液及Na_(2)CO_(3)、NaHCO_(3)共三种药剂进行中和反应,调节碱性药剂使用量,中和丙酰氯废液至中性。结合反应体系温度、pH、热值、酸雾产生情况和体系反应剧烈程度等多个指标,探究最优的中和药剂及反应条件。最优结果为:丙酰氯废液先稀释20倍,每1 g丙酰氯废液需使用2 g碳酸氢钠中和。废液中和后pH为7.0,反应体系有二氧化碳气体逸出,无温度变化,无酸雾产生,中和后废液热值为0。

磷肥副产氟硅酸制备六水合氟硅酸锌及其真空生产工艺研究

以磷肥副产氟硅酸和氧化锌为原料,通过中和反应制备得到六水合氟硅酸锌产品。为了探索工业制备六水合氟硅酸锌产品的最佳工艺条件,降低能耗并提高产品质量,系统性地研究了反应温度、反应时间、物料比等工艺参数及浓缩方式对产品含量和收率的影响。结果表明:在反应温度为30℃,反应时间为2 h,氧化锌与氟硅酸(以H2SiF4计)物质的量比为1∶1.2,浓缩方式为低温真空蒸发浓缩法(蒸发温度为45~55℃)的工艺条件下,参考企业标准(Q/KHQ 001-2016),可以制备得到六水合氟硅酸锌一等品,其质量分数为98.92%,收率为96.68%。

双碳背景下化学反应工程课程教学改革与探索

化学反应工程是高等院校化学工程与工艺专业课程体系中一门重要的专业核心基础课。在工程教育专业认证及新工科背景下,结合双碳战略目标,立足新时代、新机遇、新挑战,不断优化“化学反应工程”教学模式。从教学内容、教学设计与实施、教学评估等方面进行探索。以此为契机,导向性强化学生学习的积极性、提高学生解决实际实践工程问题的能力,以期促进化学工程与工艺专业教学体系的持久健康发展。

Single-atom catalysis for carbon neutrality

Currently,more than 86%of global energy consumption is still mainly dependent on traditional fossil fuels,which causes resource scarcity and even emission of high amounts of carbon dioxide(CO_(2)),resulting in a severe“Greenhouse effect.”Considering this situation,the concept of“carbon neutrality”has been put forward by 125 countries one after another.To achieve the goals of“carbon neutrality,”two main strategies to reduce CO_(2) emissions and develop sustainable clean energy can be adopted.Notably,these are crucial for the synthesis of advanced single-atom catalysts(SACs)for energyrelated applications.In this review,we highlight unique SACs for conversion of CO_(2) into high-efficiency carbon energy,for example,through photocatalytic,electrocatalytic,and thermal catalytic hydrogenation technologies,to convert CO_(2) into hydrocarbon fuels(CO,CH_(4),HCOOH,CH_(3)OH,and multicarbon[C_(2+)]products).In addition,we introduce advanced energy conversion technologies and devices to replace traditional polluting fossil fuels,such as photocatalytic and electrocatalytic water splitting to produce hydrogen energy and a high-efficiency oxygen reduction reaction(ORR)for fuel cells.Impressively,several representative examples of SACs(including d-,ds-,p-,and f-blocks)for CO_(2) conversion,water splitting to H2,and ORR are discussed to describe synthesis methods,characterization,and corresponding catalytic activity.Finally,this review concludes with a description of the challenges and outlooks for future applications of SACs in contributing toward carbon neutrality.

Engineering core–shell Co_(9)S_(8)/Co nanoparticles on reduced graphene oxide: Efficient bifunctional Mott–Schottky electrocatalysts in neutral rechargeable Zn–Air batteries

It is significant for the rational construction of the high–efficient bifunctional electrocatalysts for in–depth understandings of how to improve the electron transfer and ion/oxygen transport in catalyzing oxygen reduction reaction and oxygen evolution reaction(ORR and OER),but still full of vital challenges.Herein,we synthesize the novel“three–in–one”catalyst that engineers core–shell Mott–Schottky Co_(9)S_(8)/Co heterostructure on the defective reduced graphene oxide(Co_(9)S_(8)/Co–rGO).The Co_(9)S_(8)/Co–rGO catalyst exhibits abundant Mott–Schottky heterogeneous–interfaces,the well–defined core–shell nanostructure as well as the defective carbon architecture,which provide the multiple guarantees for enhancing the electron transfer and ion/oxygen transport,thus boosting the catalytic ORR and OER activities in neutral electrolyte.As expected,the integrated core–shell Mott–Schottky Co_(9)S_(8)/Co–rGO catalyst delivers the most robust and efficient rechargeable ZABs performance in neutral solution electrolytes accompanied with a power density of 59.5 mW cm^(-2) and superior cycling stability at 5 mA cm^(-2) over 200 h.This work not only emphasizes the rational designing of the high–efficient bifunctional oxygen catalysts from the fundamental understanding of accelerating the electron transfer and ion/oxygen transport,but also sheds light on the practical application prospects in more friendly environmentally neutral rechargeable ZABs.