Bio-Based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

This study presents a solvent-free,facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin(MV)using vanillin.The resulting MV not only imparted antibacterial properties to coatings layered on leather,but could also be employed as a green alternative to petroleum-based carcinogen styrene(St).Herein,MV was copolymerized with butyl acrylate(BA)to obtain waterborne bio-based P(MV-BA)miniemulsion via miniemulsion polymerization.Subsequently,MXene nanosheets with excellent photothermal conversion performance and antibacterial properties,were introduced into the P(MV-BA)miniemulsion by ultrasonic dispersion.During the gradual solidification of P(MV-BA)/MXene nanocomposite miniemulsion on the leather surface,MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene,which prompted its full exposure to light and bacteria,exerting the maximum photothermal conversion efficiency and significant antibacterial efficacy.In particular,when the dosage of MXene nanosheets was 1.4 wt%,the surface temperature of P(MV-BA)/MXene nanocomposite miniemulsioncoated leather(PML)increased by about 15℃ in an outdoor environment during winter,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100%under the simulated sunlight treatment for 30 min.Moreover,the introduction of MXene nanosheets increased the air permeability,water vapor permeability,and thermal stability of these coatings.This study provides a new insight into the preparation of novel,green,and waterborne bio-based nanocomposite coatings for leather,with desired warmth retention and antibacterial properties.It can not only realize zerocarbon heating based on sunlight in winter,reducing the use of fossil fuels and greenhouse gas emissions,but also improve ability to fight off invasion by harmful bacteria,viruses,and other microorganisms.

绿色碳科学:双碳目标下的科学基础——第292期“双清论坛”学术综述

基于第292期“双清论坛”,本文阐述了“绿色碳科学”理念的科学内涵,综述了当前我国能源与材料科技领域低碳化科学技术的研究进展、相关挑战与未来机遇,凝练了双碳目标的实现路径、关键科学问题、未来研究方向,为自然科学基金委下一步制订碳中和基础研究行动计划与资助方案提供参考。

Enhanced CO_(2)electroreduction to ethylene via strong metal-support interaction

The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density of 18 mA cm^(-2).The strong metal-support interaction could not only enhance the adsorption and activation of CO_(2),but also can stablize the CuO.

Water-mediated phase-change composite electrolyte

With the world's focus on wearable electronics, the scientific community has anticipated the plasticine-like processability of electrolytes and electrodes. A bioinspired composite of polymer and phase-changing salt with the similar bonding structure to that of natural bones is a suitable electrolyte candidate. Here, Wang et al. reported a water-mediated composite electrolyte by simple thermal mixing of crystallohydrate and polymer. The processable phase-change composites have significantly high mechanical strength and high ionic mobility.

Catalytic conversion of lignocellulosic biomass into chemicals and fuels

In the search of alternative resources to make commodity chemicals and transportation fuels for a low carbon future,lignocellulosic biomass with over 180-billion-ton annual production rate has been identified as a promising feedstock.This review focuses on the state-of-the-art catalytic transformation of lignocellulosic biomass into value-added chemicals and fuels.Following a brief introduction on the structure,major resources and pretreatment methods of lignocellulosic biomass,the catalytic conversion of three main components,i.e.,cellulose,hemicellulose and lignin,into various compounds are comprehensively discussed.Either in separate steps or in one-pot,cellulose and hemicellulose are hydrolyzed into sugars and upgraded into oxygen-containing chemicals such as 5-HMF,furfural,polyols,and organic acids,or even nitrogen-containing chemicals such as amino acids.On the other hand,lignin is first depolymerized into phenols,catechols,guaiacols,aldehydes and ketones,and then further transformed into hydrocarbon fuels,bioplastic precursors and bioactive compounds.The review then introduces the transformations of whole biomass via catalytic gasification,catalytic pyrolysis,as well as emerging strategies.Finally,opportunities,challenges and prospective of woody biomass valorization are highlighted.

Complete degradation of high-loaded phenol using tungstate-based ionic liquids with long chain substituent at mild conditions

Phenol in waste water threatens human health and is difficultly to be decomposed by nature.Efficient degradation of high-loaded phenol in water under mild condition is still a great challenge.Herein,ionic liquids with tungstate anion were designed and prepared.It was found that dodecyltrimethylammonium tungstate could catalyzed degradation of phenol into gases and water thoroughly at 323 k in 8 h.Tungstate anion revealed good catalytic oxidative activity and long carbon chain group connecting with cation of ionic liquids enriched phenol around catalysts,which induced the complete degradation of phenol at mild conditions.Increasing the amounts of hydrogen peroxide benefited to the total degradation of phenol.In addition,the ionic liquid could be reused for its excellent thermal stability.Our work provided a different strategy to treat waste water containing phenol efficiently.

Asymmetric Cu Sites for Enhanced CO_(2)Electroreduction to C_(2+)Products

Cu-based electrocatalysts can have excellent activity for the generation of C_(2+)products from a CO_(2)reduction reaction(CO_(2)RR).Cuδ+species is crucial in tuning the performance of the catalysts.Herein,we discovered that Si-doped Cu catalysts had excellent performance for electrochemical CO_(2)to C_(2+)products.A high Faradaic efficiency(FE)of 84.7%was achieved with a current density of 289mA cm^(−2)in the flow-cell system.In situ experimental results showed that the significant reconstruction occurred during the electrolysis,resulting in the formation of the asymmetric Cu sites(Cu^(0)-Cu^(+)).The ratio of Cu^(0)and Cu^(+)could be tuned by changing Si content.Controlled experiments and theoretical calculations demonstrated that the asymmetric Cu sites caused by the appropriate Si doping promoted CO_(2)activation and strengthened the adsorption of^(*)CO intermediate.This was beneficial to the subsequent^(*)CO–^(*)CO dimerization step,and thus,accounted for the enhancement of C_(2+)selectivity.

Functional zirconium phosphate nanosheets enabled transfer hydrogenolysis of aromatic ether bonds over a low usage of Ru nanocatalysts

Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals,which relies on developing innovative heterogeneous catalysts with high activity.Herein,we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts(Ru/ZrPsheet)as the heterogeneous catalyst by a process combining ball milling and molten-salt(KNO_(3)).Very interestingly,the fabricated Ru/ZrPsheetshowed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin,i.e.,4-O-5,a-O-4,β-O-4,and aryl-O-CH3,over a low Ru usage(<0.5 mol%)without using any acidic/basic additive.Detailed investigations indicated that the properties of Ru and the support were indispensable.The excellent activity of Ru/ZZrPsheetoriginated from the strong acidity and basicity of ZrPsheetand the higher electron density of metallic Ru0as well as the nanosheet structure of ZrPsheet.

Atomically Dispersed Pt and NiO Clusters Synergistically Enhanced C–O Bond Hydrogenolysis

C–Obond activation is a highly efficient,fundamental strategy in the depolymerization and hydrodeoxygenation of chemicals with oxygen-containing functional groups such as oil,coal,and biomass.Developing efficient catalysts for C–Oactivation with ultralow-loading noble and non-noble metals is highly desirable for the improvement of metal atomic utilization.Herein,bimetallic catalysts with atomically dispersed Pt and NiO clusters on different supports were fabricated,and the prepared Pt^(δ+)-NiO/Nb_(2)O_(5)and Pt^(δ+)-NiO/TiO_(2)showed outstanding activity for the hydrogenolysis of benzyl phenyl ether with>99%yield of phenol and toluene due to the excellent cooperation of atomically dispersed Pt and NiO clusters.The synergy mechanism between Pt and Ni and their respective roles in the bimetallic catalyst for C–O hydrogenolysis were clearly clarified.These findings deepen our understanding of the synergy of the two active components and are expected to provide new design concepts for the development of multicomponents catalysts.

利用空间位阻和氢溢流协同作用促进5-羟甲基糠醛选择性加氢制备5-甲基糠醛

化学工业生产中,用氢气为还原剂,通过选择性加氢可以制备多种重要化学品。5-羟甲基糠醛是重要的生物质基平台化合物,而5-甲基糠醛是用途广泛的化学品。由5-羟甲基糠醛加氢得到5-甲基糠醛是一条非常理想的路径,但是选择性活化C―OH非常困难。本文设计并制备了Pt@PVP/Nb_(2)O_(5)(PVP:聚乙烯吡咯烷酮)催化剂,该催化体系巧妙地结合了位阻效应、氢溢流和催化剂界面的电子效应,系统研究了该催化剂对5-羟甲基糠醛选择性加氢制备5-甲基糠醛催化性能,在最优条件下,5-甲基糠醛的选择性可达92%。利用密度泛函理论计算研究了5-羟甲基糠醛选择性加氢制备5-甲基糠醛反应路径。

Efficient electrocatalytic reduction of carbon dioxide to ethylene on copper–antimony bimetallic alloy catalyst

The exploration of efficient electrocatalysts for the reduction of CO2 to C2H4 is of significant importance but is also a challenging subject.Cu-based bimetallic catalysts are extremely promising for efficient CO2 reduction.In this work,we synthesize a series of porous bimetallic Cu–Sb alloys with different compositions for the catalytic reduction of CO2 to C2H4.It is demonstrated that the alloy catalysts are much more efficient than the pure Cu catalyst.The performance of the alloy catalysts depended strongly on the composition.Further,the alloy with a Cu:Sb ratio of 10:1 yielded the best results;it exhibited a high C2H4 Faradaic efficiency of 49.7%and a high current density of 28.5 mA cm?2 at?1.19 V vs.a reversible hydrogen electrode(RHE)in 0.1 M KCl solution.To the best of our knowledge,the electrocatalytic reduction of CO2 to C2H4 using Cu–Sb alloys as catalysts has not been reported.The excellent performance of the porous alloy catalyst is attributed to its favorable electronic configuration,large surface area,high CO2 adsorption rate,and fast charge transfer rate.

Sm and S Co-doping to Construct Homo-hetero Cu Catalysts for Synergistic Enhancing CO_(2) Electroreduction

Copper(Cu)is recognized as one of the most efficient metal catalysts that can perform the electrocatalytic CO_(2) reduction reaction(CO_(2)RR)and its surface oxidation state determines the reaction pathway.The Cuδ+(0<δ<1)species,are well known active sites in CO_(2)RR to produce hydrocarbons and oxygenates.However,Cuδ+active sites are difficult to control,and it is very easy to be reduced to Cu^(0) under CO_(2)RR operating conditions.Herein,we report a homo-hetero doping strategy to construct an efficient samarium(Sm)and sulfur(S)co-doping catalyst(Smx-CuSy)for CO_(2)RR to formic acid(HCOOH).At optimum conditions,Smx-CuSy delivered a high HCOOH Faradaic efficiency(FE)of 92.1%at the current density of 300 mA·cm^(–2) using 1 mol/L KOH aqueous solution as electrolyte,and the reduction potential was as low as–0.52 V vs.reversible hydrogen electrode(RHE).The co-doping of Sm and S resulted in excellent CO_(2)RR performance owing to the synergistic effect of the homo-hetero structure.The homo-doping of S could effectively adjust the electronic structure of Cu in favor of the formation of abundant Cu^(δ+)species.The existence of hetero-Sm species could not only stabilize the Cu^(δ+)sites,but also increase the concentration of H ions to form a favorable catalytic environment for HCOOH generation.

Selective production of diethyl maleate from lignin

Lignin is an abundant and renewable carbon resource and also a by-product in the paper industry.Transformation of lignin into valuable chemicals and liquid fuels has attracted extensive interest.Selective lignin depolymerization is a potentially important strategy to reduce fossil resource consumption.Currently,lignin is an underutilized resource of biomass compared to either cellulose or hemicellulose.It has great potential for the generation of biochemicals and fuels due to its highly aromatic structure[1].However,efficient utilization of lignin requires the selective breakdown of the recalcitrant polymeric structure[1–3].Catalytic oxidation is one of the most promising routes to depolymerize lignin,which can produce value-added chemicals,such as phenols,quinines,and dicarboxylic acids[4].Nevertheless,controlling the oxidative pathways of lignin and its intermediates to get pure chemicals is a great challenge because of the complex structure of lignin.

Construction of Synergistic Co and Cu Diatomic Sites for Enhanced Higher Alcohol Synthesis

Higher alcohol synthesis(HAS)from syngas could efficiently alleviate the dependence on the traditional fossil resources.However,it is still challenging to construct high-performance HAS catalysts with satisfying selectivity,space–time yield(STY),and stability.Herein,we designed a diatomic catalyst by anchoring Co and Cu sites onto a hierarchical porous N-doped carbon matrix(Co/Cu–N–C).The Co/Cu–N–C is efficient for HAS and is among the best catalysts reported.With a COconversion of 81.7%,C2+OHselectivity could reach 58.5%with an outstanding C2+OH STY of 851.8 mg/g·h.We found that the N4–Co1 and Cu1–N4 showed an excellent synergistic effect.The adsorption of CO occurred on the Co site,and the surrounding nitrogen sites served as a hydrogen reservoir for the CO reduction reactions to form CHxCo.Meanwhile,the Cu sites stabilized a CHOCu species to interact with CHxCo,facilitating a barrier-free formation of C2 species,which is responsible for the high selectivity of higher alcohols.

In-situ tracking CO_(2)-assisted isothermal-isobaric synthesis of selfassembled Bi-based photocatalyst using novel SAXS/XRD/XAFS combined technique

The synthetic path of a catalyst determines its morphology,species,and performance,and in-situ monitoring the catalyst formation process is fascinating and challenging.Herein,a newly developed synchrotron radiation smallangle X-ray scattering/X-ray diffraction/X-ray absorption fine structure(SAXS/XRD/XAFS)combined technique was used to in-situ monitor the isothermal-isobaric synthesis process of CO_(2)-assisted(BiO)_(2)CO_(3)(BOC)photocatalyst,and the atomic near-neighbor structure,crystalline structure and nanoscale particle size evolution with reaction time were simultaneously captured.The results show that both polyvinyl pyrrolidone and CO_(2)formed uniformly-distributed nano-sized scatterers in the Bi-based precursor solution,presenting short-range ordered structures to a certain extent.The as-prepared BOC catalytic particles underwent the evolution process of initial Bi(OH)3 precipitate,early-stage formed KBiO_(2)molecules,intermediate amorphous(BiO)4CO3(OH)2 nanoparticles,and finally crystallized flower-like BOC particles self-assembled by nanosheets.The flower-like BOC particles,Bi/BOC composite,and Bi nanospheres were further prepared with different synthesis paths.Flower-like BOC particles showed the best photocatalytic degradation performance of RhB.Scavenger experiment and theoretical calculation revealed the photocatalytic mechanisms of BOC.This work has implications for path-dependent synthesis of other catalysts.

Efficient nitrate electroreduction over Mn-doped Cu catalyst via regulating N-containing intermediates adsorption configuration

The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).

Electrochemical CO_(2)reduction to C_(2+)products over Cu/Zn intermetallic catalysts synthesized by electrodeposition

Electrocatalytic CO_(2)reduction(ECR)offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO_(2)as the feedstock.However,the lack of cost-effective electrocatalysts with better performances has seriously hindered its application.Herein,a one-step co-electrodeposition method was used to introduce Zn,a metal with weak^(*)CO binding energy,into Cu to form Cu/Zn intermetallic catalysts(Cu/Zn IMCs).It was shown that,using an H-cell,the high Faradaic efficiency of C_(2+)hydrocarbons/alcohols()could be achieved in ECR by adjusting the surface metal components and the applied potential.In suitable conditions,FEC_(2+)and current density could be as high as 75%and 40 mA/cm^(2),respectively.Compared with the Cu catalyst,the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area(ECSA),which accelerate the reaction.Moreover,the^(*)CO formed on Zn sites can move to Cu sites due to its weak binding with*CO,and thus enhance the C–C coupling on the Cu surface to form C_(2+)products.

Tuning the Surface Field by Embedding Cations into Metals to Direct the Reaction Pathway of CO_(2) Electroreduction

The creation of universal strategies to affect the reaction route of the electroreduction of CO_(2) is critical.Here,we report the first work to introduce cations into diverse metals such as Cu,Bi,In,and Sn via the electroreduction of related metallic oxides in quaternary ammonium surfactant solutions.Compared to their physical adsorption,cations embedded into the electrodes have a more pronounced impact on the electrical field,which effectively influences the adsorption state of intermediates.With the increase of surface field,the hydrogen evolution reaction and*COOH route are significantly reduced,favouring the*OCHO pathway instead.As a result,hydrogen,CO,and C_(2+)products almost completely vanish at−0.5 V versus RHE in 0.1 M Na_(2)SO_(4)in an H-type cell after enough cations are embedded into the Cu electrode,and the faradaic efficiency of formate rises from 18.0%to 99.5%simultaneously.

Supercritical CO2 produces the visible-light-responsive TiO2/COF heterojunction with enhanced electron-hole separation for highperformance hydrogen evolution

To construct the heterojunctions of TiO2 with other compounds is of great importance for overcoming its inherent shortages and improving the visible-light photocatalytic performance.Here we propose the construction of TiO2/covalent organic framework(COF)heterojunction with tight connection by a supercritical CO2(SC CO2)method,which helps bridging the transformation paths for photo-induced charge between T i02 and COF.The produced T i02/COF heterojunction performs a H2 evolution of 3,962 nmol·g^-1·h^-1 under visible-light irradiation,which is-25 times higher than that of pure TiO2 and 4.5 folds higher than that of TiO2/COF synthesized by the conventional solvothermal method.This study opens up new possibilities for constructing heterojunctions for solar energy utilization.

Enhancing the selective hydrogenation of benzene to cyclohexene over Ru/TiO_2 catalyst in the presence of a very small amount of ZnO

Highly efficient and greener hydrogenation of benzene to cyclohexene is of great importance but is challenging.In this work,Ru/Ti O2 catalyst was prepared by a simple chemical-reduction method.The catalyst was characterized by transmission electron spectroscopy(TEM),X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and nitrogen adsorption-desorption techniques.It was shown that the Ru nanoparticles with average size of about 2.2 nm were dispersed uniformly on the surface of the Ti O2 support.The effect of a very small amount of Zn O in Na OH solution on the selectivity to cyclohexene was investigated under different conditions by using Ru/Ti O2 catalyst.It was found that the addition of a small amount of Zn O to the Na OH solution could effectively enhance the selectivity to cyclohexene and that the yield of cyclohexene could reach 41.5%.Control experiments revealed that the main reason for the enhancement of the selectivity to cyclohexene was the presence of Zn O in the form of Na2Zn(OH)4 in the alkaline solution,which effectively retarded the further hydrogenation of cyclohexene.A recycling experiment showed that the yield of cyclohexene was not obviously decreased after four reuses.