Enabling heterogeneous catalysis to achieve carbon neutrality: Directional catalytic conversion of CO_(2) into carboxylic acids

The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.

Strategies to achieve effective nitrogen activation

Ammonia serves as a crucial chemical raw material and hydrogen energy carrier.Aqueous electrocatalytic nitrogen reduction reaction(NRR),powered by renewable energy,has attracted tremendous interest during the past few years.Although some achievements have been revealed in aqueous NRR,significant challenges have also been identified.The activity and selectivity are fundamentally limited by nitrogen activation and competitive hydrogen evolution.This review focuses on the hurdles of nitrogen activation and delves into complementary strategies,including materials design and system optimization(reactor,electrolyte,and mediator).Then,it introduces advanced interdisciplinary technologies that have recently emerged for nitrogen activation using high-energy physics such as plasma and triboelectrification.With a better understanding of the corresponding reaction mechanisms in the coming years,these technologies have the potential to be extended in further applications.This review provides further insight into the reaction mechanisms of selectivity and stability of different reaction systems.We then recommend a rigorous and detailed protocol for investigating NRR performance and also highlight several potential research directions in this exciting field,coupling with advanced interdisciplinary applications,in situ/operando characterizations,and theoretical calculations.

A techno-economic and life cycle assessment for the production of green methanol from CO_(2): catalyst and process bottlenecks

The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process design.Here we present a multidisciplinary study(from catalyst to plant and techno-economic/lifecycle analysis)for the production of green methanol from renewable H2 and CO_(2).We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts(InCo)with a thorough process simulation and techno-economic assessment.We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO_(2).Our results indicate that up to 1.75 ton of CO_(2) can be abated per ton of produced methanol only if renewable energy is used to run the process,while the sensitivity analysis suggest that either rock-bottom H2 prices(1.5$kg1)or severe CO_(2) taxation(300$per ton)are needed for a profitable methanol plant.Besides,we herein highlight and analyze some critical bottlenecks of the process.Especial attention has been paid to the contribution of H2 to the overall plant costs,CH4 trace formation,and purity and costs of raw gases.In addition to providing important information for policy makers and industrialists,directions for catalyst(and therefore process)improvements are outlined.

Growth behavior and electronic properties of Ge_(n+1) and AsGe_n(n = 1–20) clusters: a DFT study

We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of different isomers of Ge_(n+1) clusters with n = 1–20 atoms. By considering a large number of structures for each cluster size, the lowest-energy isomers are determined. The lowest-energy isomers reveal three-dimensional structures starting from n = 5. Their relative stability versus atomic size is examined based on the calculated binding energy, fragmentation energy, and second-order difference of energy. Doping Ge_(n+1) clusters with one As atom does not improve their stability. The electronic properties as a function of the atomic size are also discussed from the calculated HOMO–LUMO energy gap, vertical ionization potential, vertical electron affinity, and chemical hardness. The obtained results are significantly affected by the inclusion of one As atom into a Gen cluster.

Tuning the electronic structure of the earth-abundant electrocatalysts for oxygen evolution reaction(OER)to achieve efficient alkaline water splitting-A review

Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces the significance of the tuning of electronic structure,where modifying the electronic structure of the electrocatalysts could generate active sites having optimal adsorption energy with OER intermediates,and that could diminish the energy barrier for OER,and that could improve the activity for OER.Later,this paper reviews the tuning of electronic structure along with catalytic performances,synthetic methodologies,chemical properties,and DFT calculations on various nanostructured earth-abundant electrocatalysts for OER in alkaline environment.Further,this review discusses the tuning of the electronic structure of the several nanostructured earth-abundant electrocatalysts including oxide,(oxy)hydroxide,layered double hydroxide,alloy,metal phosphide/phosphate,nitride,sulfide,selenide,carbon containing materials,MOF,core-shell/hetero/hollow structured materials,and materials with vacancies/defects for OER in alkaline environment(including activity:overpotential(η)of ≤200 mV at10 m A cm^(-2);stability:≥100 h;durability:≥5000 cycles).Then,this review discusses the robust stability of the electrocatalysts for OER towards practical application.Moreover,this review discusses the in situ formation of thin layer on the catalyst surface during OER.In addition,this review discusses the influence of the adsorption energy of the OER intermediates on OER performance of the catalysts.Finally,this review summarizes the various promising strategies for tuning the electronic structure of the electrocatalysts to achieve enhanced performance for OER in alkaline environment.

Merging Electrolysis and Nickel Catalysis in Redox Neutral Cross-Coupling Reactions:Experiment and Computation for Electrochemically Induced C–P and C–Se Bonds Formation

We have achieved a nickel-catalyzed cross-coupling reaction via concerted paired electrolysis under mild reaction conditions.In this electrochemical transformation,the anodic oxidation of NiII to NiIII and cathodic reduction of NiI to Ni0 occurred simultaneously,resulting in an economical and sustainable cross-coupling protocol.Moreover,weperformed mechanistic investigations,achieved by experiments and density functional theory(DFT)calculations for different C–heteroatom bond formations to reveal the catalytic cycle in more detail.

Green and large-scale production of ammonia:Laser-driven pyrolysis of nitrogen-enriched biomass

As a vital chemical,ammonia(NH3)plays an irreplaceable role in many fields such as chemical synthesis and energy storage.Green renewable biomass can be converted into biofuels,but its nitrogen resources are underused throughout.Laser-driven pyrolysis is envisaged to debuts as a bridge to connect them to realize the direct conversion from nitrogen-rich biomass into ammonia.The pulsed laser-induced local-transient thermal effect recognized the biological nitrogen resources conversion,such as cheap and plentiful yeasts,to small gaseous molecules and achieved spectacular ammonia production rate up to 260.4 mg/h,an order of magnitude higher performance than thermochemical ammonia synthesis.Simultaneously,the tiny hot point generated by a low-energy laser(20W)guarantees the whole ammonia synthesis reaction systemis in amild environment of low temperature and normal pressure.Additionally,the remaining solid residue after laser-driven pyrolysis also can be further exploited as a highly active catalyst for electrocatalytic nitrate reduction reaction(NIRR).

Water-ultrastable perovskite CsPbBr_(3)nanocrystals for fluorescence-enhanced cellular imaging

Metal halide perovskites have attracted much attention in biomedicine because of their excellent fluorescence energy conversion properties;however,poor water-stability and cytotoxicity limit its applications as a biomedical tracer,especially in cellular imaging.Herein,water-ultrastable perovskites C sPbBr_(3):Cs_(4)PbBr_(6)nanocrystals(NCs)encapsulated in chitosan are fabricated successfully using a water-triggered method.The as-synthesized CsPbBr_(3):Cs_(4)PbBr_(6)@CS(chitosan,CS)nanoparticles in water display enhanced fluorescence emission for 35 days.Further,the viability of glioma cells(U87 cells)incubated with different concentrations of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles(0-20μg·ml^(-1))for24 h is found to be higher than 90%.In artificial body fluid,analyses using laser confocal microscopy,the standard Cell Counting Kit-8(CCK-8)method,and flow cytometry demonstrated the good water ultrastability and high biocompatibility performance of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles in cellular imaging.Overall,the water-ultrastable halide perovskites support promising perspectives in biological cell tracing and intelligent medical technology.

三氨基环丙烯离子(TAC^(+))催化的光电协同邻位C–H键接力氧化

The development of general,straightforward,and practical methodologies to assemble complex structural skeletons under mild reaction conditions is a long-pursued goal in organic chemistry.Photocatalysis and electrocatalysis represent two of the most promising processes towards this objective,and in addition to their mild and scalable operating conditions.

基于电化学钴催化C-H活化的多样化手性骨架的构建

Transition metal-catalyzed C-H functionalizations,which transform ubiquitous C-H bonds into diverse and valuable functionalities in a single step,have emerged as a direct and efficient methodology for constructing synthetically useful and multifunctional organic molecules[1].Despite the significant advantages,some drawbacks such as the requirement of a stoichiometric amount of chemical oxidant and the resulting low functional group tolerance,byproduct generation and separation issues remain to be solved(Fig.1a).Notably,the development of electrochemistry has introduced new dimensions to the field of organic synthesis[2].Employing electric energy as both an oxidant and a reductant in a single process,electrochemistry offers numerous advantages,including mild reaction conditions,a wide substrate scope,and enhanced sustainability.

Si Doping-Induced Electronic Structure Regulation of Single-Atom Fe Sites for Boosted CO_(2) Electroreduction at Low Overpotentials

Transition metal-based single-atom catalysts(TM-SACs)are promising alternatives to Au-and Ag-based electrocatalysts for CO production through CO_(2)reduction reaction.However,developing TM-SACs with high activity and selectivity at low overpotentials is challenging.Herein,a novel Fe-based SAC with Si doping(Fe-N-C-Si)was prepared,which shows a record-high electrocatalytic performance toward the CO_(2)-to-CO conversion with exceptional current density(>350.0 mA cm^(−2))and~100%Faradaic efficiency(FE)at the overpotential of<400 mV,far superior to the reported Fe-based SACs.Further assembling Fe-N-C-Si as the cathode in a rechargeable Zn-CO_(2)battery delivers an outstanding performance with a maximal power density of 2.44 mW cm^(−2)at an output voltage of 0.30 V,as well as high cycling stability and FE(>90%)for CO production.Experimental combined with theoretical analysis unraveled that the nearby Si dopants in the form of Si-C/N bonds modulate the electronic structure of the atomic Fe sites in Fe-N-C-Si to markedly accelerate the key pathway involving^(*)CO intermediate desorption,inhibiting the poisoning of the Fe sites under high CO coverage and thus boosting the CO_(2)RR performance.This work provides an efficient strategy to tune the adsorption/desorption behaviors of intermediates on singleatom sites to improve their electrocatalytic performance.

Controlling N-doping type in carbon to boost single-atom site Cu catalyzed transfer hydrogenation of quinoline

Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.

全无机卤素钙钛矿中的量子限域效应（英文）

当半导体材料尺寸缩小到与激子尺寸相当时,量子限域效应会在对应的低维材料中诱导出不同的物理行为.本文以CsPbBr_3为例,报道了在全无机钙钛矿纳米片中的量子限域效应.根据DFT理论模拟可知,当CsPbBr_3材料减薄至7纳米左右时,该效应导致该材料的光吸收和光致发光光谱的峰位蓝移,且样品越薄,峰位蓝移现象越明显.该效应也会导致激子束缚能随着材料厚度的减薄而显著增大.同时,变温光致发光光谱的光强-温度与半高宽-温度函数都显示出厚度越薄量子限域效应越强的趋势.本文揭示了二维全无机卤化物钙钛矿的量子限域效应,可为设计全无机卤化物钙钛矿光电器件提供参考依据.

2020 roadmap on pore materials for energy and environmental applications

Porous materials have attracted great attention in energy and environment applications,such as metal organic frameworks(MOFs),metal aerogels,carbon aerogels,porous metal oxides.These materials could be also hybridized with other materials into functional composites with superior properties.The high specific area of porous materials offer them the advantage as hosts to conduct catalytic and electrochemical reactions.On one hand,catalytic reactions include photocatalytic,p ho toe lectrocatalytic and electrocatalytic reactions over some gases.On the other hand,they can be used as electrodes in various batteries,such as alkaline metal ion batteries and electrochemical capacitors.So far,both catalysis and batteries are extremely attractive topics.There are also many obstacles to overcome in the exploration of these porous materials.The research related to porous materials for energy and environment applications is at extremely active stage,and this has motivated us to contribute with a roadmap on ’porous materials for energy and environment applications’.

Surface decorated Ni sites for superior photocatalytic hydrogen production

Precise construction of isolated reactive centers on semiconductors with well-controlled configurations affords a great opportunity to investigate the reaction mechanisms in the photocatalytic process and realize the targeted conversion of solar energy to steer the charge kinetics for hydrogen evolution.In the current research,we decorated isolated Ni atoms on the surface of CdS nanowires for efficient photocatalytic hydrogen production.X-ray absorption fine structure investigations clearly demonstrate the atomical dispersion of Ni sites on the surface of CdS nanowires.Experimental investigations reveal that the isolated Ni atoms not only perform well as the real reactive centers but also greatly accelerate the electron transfer via direct Ni-S coordination.Theoretical simulation further documents that the hydrogen adsorption process has also been enhanced over the semi-coordinated Ni centers through electronic coupling at the atomic scale.

Tungsten Blue Oxide as a Reusable Electrocatalyst for Acidic Water Oxidation by Plasma-Induced Vacancy Engineering

In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.

Transition-metal-catalyzed switchable divergent cycloaddition of para-quinone methides and vinylethylene carbonates:Access to different sized medium-sized heterocycles

Divergent synthesis of medium-sized rings with controllable ring sizes represents a longstanding challenge in organic synthesis.Herein,we developed a transition-metal-catalyzed switchable divergent cycloaddition of para-quinone methides and vinylethylene carbonates by controlling the steric hindrance of substituent.Different from reported alkoxide-triggered annulations,this process undergoes a regiodivergent allylation of para-quinone methides followed by 1,6-addition reaction,providing a new route to selectively synthesize seven-to ten-membered nitrogen-containing heterocycles in high yields with excellent regioselectivities.This protocol features a broad substrate scope,wide functional group tolerance as well as operational simplicity.The reaction mechanism was investigated by conducting a series of control experiments as well as DFT calculations and the origins of the regioselectivities of the cycloaddition process were rationalized.

Kinetically accelerated and high-mass loaded lithium storage enabled by atomic iron embedded carbon nanofibers

Carbonaceous materials represent the dominant choice of materials for anodic lithium storage in many energy storage devices.Nevertheless,the nonpolar carbonaceous materials offer weak adsorption toward Li+that largely denies the high-rate Li+storage.Herein,the atomic Fe sites decorated carbon nanofibers(AICNFs)facilely produced by electrospinning are reported for kinetically accelerated Li+storage.Theoretical calculation reveals that the atomic Fe sites possess coordination unsaturated electronic configuration,enabling suitable bonding energy and facilitated diffusion path of Li+.As a result,the optimal structure displays a high capacitive contribution up to 95.9%at a scan rate of 2.0 mV·s^(−1).In addition,ultrahigh capacity retention of 97%is afforded after 5,000 cycles at a current density of 3 A·g^(−1).Moreover,the interlaced fiber structure enabled by electrospinning benefits structural stability and improved conductivity even at thick electrodes,thus allowing a high areal capacity of 1.76 mAh·cm−2 at a loading of 8 mg·cm−2.Because of these structure and performance merits,the lithium-ion capacitor containing the AICNF-based anode delivers a high energy density and large power density.

Electrophilic N-trifluoromethylthiophthalimide as a fluorinated reagent in the synthesis of acyl fluorides

Herein we report the deoxygenated fluorination of readily available carboxylic acids.A series of acyl fluorides have been synthesized using shelf-stable N-trifluoromethylthiophthalimide as a fluorinated reagent for the first time.Scale-up reactions and sequential cross-couplings were performed successfully to demonstrate the practicability of this fluorination protocol.

Toward Liquid Phase Processable Metal Organic Frameworks:Dream or Reality?

CONSPECTUS:Conventionally,the virtue of porosity is only given to porous solids.Metal Organic Frameworks(MOFs),carbon materials,or zeolites are some examples.However,processing these solids is not a straightforward task.Here,we discuss how to endow porous solids(MOFs)with liquid phase processability.More specifically,we show that surface modification of MOF crystals can lead to the formation of porous liquids(PLs)that can be further processed in the liquid phase.For instance,when placed in mesitylene,ZIF-67 predictably sediments.In contrast,with the adequate surface modification,stable dispersion of ZIF-67 can be achieved.Our proposed surface modification is facile and rapid.N-Heterocyclic carbenes are chosen as modifying agents as they are similar to imidazole linkers present on ZIFs.A simple stirring of a MOF and carbene mixture results in a modified solid.The morphology and textural properties of the modified MOF do not change from the ones of its parent.Since the porosity in solution remains unoccupied,the obtained stable colloids behave as porous liquids.Research into porous liquids is an emerging field that has already shown great promise in gases storage.Our breakthrough experiments show that these particular PLs have large potential for the separation of CO_(2)/CH_(4)mixtures.