Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells.The modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/C.Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct pathway.Density functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic performance.This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

A H_(4)SiW_(12)O_(40)-catalyzed three-component tandem reaction for the synthesis of 3,3-disubstituted isoindolinones

A H_(4)SiW_(12)O_(40)-catalyzed three-component tandem reaction of 2-acylbenzoic acids,primary amines and phosphine oxides to form 3,3-disubstituted isoindolinones was developed.By employing A H_(4)SiW_(12)O_(40)as the catalyst and dimethyl carbonate(DMC)as the solvent,a diverse range of 2-acylbenzoic acid derivatives and primary amines worked well to give the C3-phosphinoyl-functionalized 3,3-disubstituted isoindolinones with the yield range of 61%-87%.Advantages of this transformation include green catalyst and solvent,available starting materials,broad substrate scope,high efficiency and operational simplicity with water as the sole by-product.The strategy achieved an efficient and green molecular fragment assembly to access isoindolinones,which would provide opportunities for the synthesis of potential biologically active molecules in a green manner.

Confined interface engineering of self-supported Cu@N-doped graphene for electrocatalytic CO_(2) reduction with enhanced selectivity towards ethanol

Electroreduction of greenhouse gas CO_(2) into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change.However,the regulations of the selectivity towards C2 product and the competing hydrogen evolution reaction(HER)are major challenges for CO_(2) reduction reaction(CO_(2)RR).Here,we develop an interface-enhanced strategy by depositing a thin layer of nitrogen-doped graphene(N-G)on a Cu foam surface(Cu-N-G)to selectively promote the ethanol pathway in CO_(2)RR.Compared to the undetectable ethanol selectivity of pure Cu and Cu@graphene(Cu-G),Cu-N-G has boosted the ethanol selectivity to 33.1%in total Faradic efficiency(FE)at−0.8 V vs.reversible hydrogen electrode(RHE).The experimental and density functional theory(DFT)results verify that the interconnected graphene coating can not only serve as the fast charge transport channel but also provide confined nanospace for mass transfer.The N doping can not only trigger the intrinsic interaction between N in N-G and CO_(2) molecule for enriching the local concentration of reactants but also promote the average valence state of Cu for C–C coupling pathways.The confinement effect at the interface of Cu-N-G can not only provide high adsorbed hydrogen(Had)coverage but also stabilize the key*HCCHOH intermediate towards ethanol pathway.The provided interface-enhanced strategy herein is expected to inspire the design of Cubased CO_(2)RR electrocatalysts towards multi-carbon products.

Reducing obesity and inflammation in mice with organically-derivatized polyoxovanadate clusters

Obesity,characterized by the dysregulation of energy balance in adipose tissue and other metabolic organs,is frequently accompanied by chronic low-grade inflammation.As long-acting insulin sensitizers,the organically-derivatized polyoxovanadates(POVs),can extend the dosing interval of antidiabetic drugs from hourly to almost daily.In this work,the protective activity of POVs is investigated by an eight-week in vivo experiment,in which a small amount of POVs was administrated orally to a mouse model of dietinduced obesity every day.The present study shows that administration of POVs significantly decreases the body weight of mice,reduces adipose tissue accumulation,and simultaneously reduces adipose tissue inflammation.In addition,the anti-obesogenic population of i NKT cells is protected potentially by POVs,which subsequently alleviates visceral adipose tissue inflammation in high-fat-diet(HFD)-fed mice against diet-induced obesity.By contrast,the change in body weight after POV treatment is the result of a substantial reduction in fat mass,with no obvious effects on lean body mass.These findings demonstrate that supplementary of POVs would be an effective way to combat obesity and metabolic disorders while lowering metabolic inflammation.

Recent advances on catalysts for preferential oxidation of CO

The trace amount of CO in H2-rich gas poisons Pt electrode when it is adopted as feedstock for proton-exchange-membrane fuel cells.Preferential oxidation of CO(PROX)is a promising approach to selectively oxidize the trace amount of CO while keeping H2 unoxidized.Catalyst plays important roles in PROX.To date,enormous catalysts have been developed for PROX.Summarizing the catalysts developed for PROX and unveiling the reaction mechanism could definitely advance this research field.Herein,in this review,according to the nature of the active sites on the catalysts,we classify the catalysts into group VIII metal-based catalyst,group IB metal-based catalysts,group VIII-group IB bimetallic catalysts,transitional metal oxide catalysts as well as others,describe the progress of the catalysts in PROX in the latest five years,and extract the underlying reaction mechanism,with the aim to provide guidance for the rational design of efficient catalysts in the future.

Additive-Mediated Selective Oxidation of Alcohols to Esters via Synergistic Effect Using Single Cation Cobalt Catalyst Stabilized with Inorganic Ligand

The direct catalytic oxidation of alcohols to esters is very appealing,but the economical-friendly catalysis systems are not yet well established.Herein,we show that a pure inorganic ligand-supported single-atomic cobalt compound,(NH_(4))_(3)[CoMo_(6)O_(18)(OH)_(6)](simplified as CoMo_(6)),could be used as a heterogeneous catalyst and effectively promote this type of reaction in the presence of 30%H_(2)O_(2)using KCl as an additive.The oxidative cross-esterification of various alcohols(aromatic and aliphatic)could be achieved under mild conditions in nearly all cases,affording the corresponding esters in high yields,including several drug molecules and natural products.Detailed studies have revealed that chloride ion is able to bind to the CoMo_(6)to form a supramolecular dimer 2(CoMo_(6)∙Cl),which can effectively catalyze the reaction via a synergistic effect from chloride ion and CoMo_(6).Mechanism studies and control reactions demonstrate that the esterification proceeds via the key oxidative immediate of aldehydes.

Polyoxometalates based compounds for green synthesis of aldehydes and ketones

Molecular oxygen within Polyoxometalates(POMs)based compounds are ideal oxidants with high atom economy and its use results in the production of water as the only byproduct.Significant progress has been made in the development of catalytic methods for aerobic alcohol oxidation to have aldehydes and ketones with POMs based compounds.They are alternative to the use of traditional hypervalent iodine catalyst systems which are with molecular oxygen as a terminal oxidant.Further,POMs based catalysts can be applied to catalytic reactions with different modes of energization such as thermocatalysis,photocatalysis and electrocatalysis.This review summarizes the frontier advances in polyoxometalates for catalytic alcohol selective oxidation in thermocatalytic,electrocatalytic,and photocatalytic applications.The three advantages of POM catalysts in terms of performance,economy,and environmental protection are highlighted.These include the use of sol-gel and electrostatic assembly methods to increase the reaction surface area,reduce the use of precious metals,and improve the stability of POMs catalysts.The field of selective alcohol oxidation is advanced.Finally,the challenges of preparing more efficient and“green”catalysts are presented.

Emulsion interfacial polymerization of anticancer peptides:fabricating polypeptide nanospheres with high drug-loading efficiency and enhanced anticancer activity

The development of drug delivery systems with high drug-loading efficiency, kinetic stability against dilution, as well as enhanced anticancer activity is of crucial importance to the fields of self-assembly and nanomedicine. Herein, we propose a strategy where the anticancer peptide acts as water-soluble monomer to directly participate in emulsion interfacial polymerization for fabricating polypeptide nanospheres. The constructed polypeptide nanospheres hold a high drug loading efficiency of 77%, and can be stably dispersed in highly diluted aqueous solutions. The acid-labile amide linkage in polypeptide nanospheres can be hydrolyzed in tumor acidic environments, thus releasing anticancer peptides selectively. The polypeptide nanospheres achieve significantly enhanced anticancer activity against HCT116 cells in vitro and in vivo through improved mitochondrial and membrane disruption. In addition, its side effects on normal cells can be reduced significantly. It is highly anticipated that more kinds of anticancer drug candidates or anticancer drugs can be applied to fabricate polymeric nanomedicines with improved anticancer activity through this strategy.

Preparation and spectral characteristics of anthracene/tetracene mixed crystals

A series of tetracene-doped anthracene crystals with different doping concentrations(the highest mo-lar ratio 100:1) are grown from solution.Crystal structures and optical characteristics of the above mixed crystals are investigated at room temperature.By changing the doping concentrations,the fluorescence can be adjusted from blue-green to green and even to yellow-green.The emission spectra of anthracene/tetracene(An/Te) mixed crystals reveal the sensitized fluorescence of tetracene and the partial quenching of anthracene emission.The data of transient photoluminescence(PL) decays illus-trate that in An/Te mixed crystals,the decay of anthracene becomes faster,while the PL lifetime of tet-racene is longer than that of the tetracene single crystals.All above experimental results suggest that there is excitation energy transfer from anthracene to tetracene in the mixed crystals.

A novel family of diarylethene-phthalocyanine dyad systems for nondestructive data processing

A novel family of diarylethene (DTE)-phthalocyanine (Pc) dyad systems were designed and synthesized. It was found that the significant change in the extension of the linear π-conjugation of DTE when irradiated by 254 nm UV light directly made the absorption of the Q-band of phthalocyanine decrease. Detecting the absorption changes of the Q-band would not induce the reversible photochromic reaction. Therefore, non-destructive readout was feasible based on the spectral changes of the Q-band when such materials were used as storage media.

Interface-rich Au-doped PdBi alloy nanochains as multifunctional oxygen reduction catalysts boost the power density and durability of a direct methanol fuel cell device

The development of cathode oxygen reduction reaction(ORR)catalysts with high characteristics for practical,direct methanol fuel cells(DMFCs)has continuously increased the attention of researchers.In this work,interface-rich Au-doped PdBi(PdBiAu)branched one-dimensional(1D)alloyed nanochains assembled by sub-6.5 nm particles have been prepared,exhibiting an ORR mass activity(MA)of 6.40 A·mgPd^(−1) and long-term durability of 5,000 cycles in an alkaline medium.The MA of PdBiAu nanochains is 46 times and 80 times higher than that of commercial Pt/C(0.14 A·mgPt^(−1))and Pd/C(0.08 A·mgPd^(−1)).The MA of binary PdBi nanochains also reaches 5.71 A·mgPd^(−1).Notably,the PdBiAu nanochains exhibit high in-situ carbon monoxide poisoning resistance and high methanol tolerance.In actual DMFC device tests,the PdBiAu nanochains enhance power density of 140.1 mW·cm^(−2)(in O_(2))/112.4 mW·cm^(−2)(in air)and durability compared with PdBi nanochains and Pt/C.The analysis of the structure–function relationship indicates that the enhanced performance of PdBiAu nanochains is attributed to integrated functions of surficial defect-rich 1D chain structure,improved charge transfer capability,downshift of the d-band center of Pd,as well as the synergistic effect derived from“Pd-Bi”and/or“Pd-Au”dual active sites.

Dissipative Supramolecular Polymerization Powered by Light

A new method of light-powered dissipative supra-molecular polymerization is established,in which supramolecular polymerization is implemented in the far-from-equilibrium state.A bifunctional mono-mer containing two viologen moieties was designed.Upon inputting energy by light,the sys-tem was driven far from equilibrium,and the mono-mers were photoreduced and activated to form supramolecular polymers driven by 2∶1 host–guest complexation of the viologen cation radical and cucurbit[8]uril.As the system returned to equilibri-um,the supramolecular polymers depolymerized spontaneously by air oxidation.This method works in both linear and in cross-linked supramolecular polymerization.The strategy of light-powered dis-sipative supramolecular polymerization is anticipat-ed to have potential in the fabrication of functional supramolecular materials,especially in creating novel“living”materials.

PtCu subnanoclusters epitaxial on octahedral PtCu/Pt skin matrix as ultrahigh stable cathode electrocatalysts for room-temperature hydrogen fuel cells

Achieving stable surface structures of metal catalysts is an extreme challenge for obtaining long-term durability and meeting industrial application requirements.We report a new class of metal catalyst,Pt-rich PtCu heteroatom subnanoclusters epitaxially grown on an octahedral PtCu alloy/Pt skin matrix(PtCu1.60),for the oxygen reduction reaction(ORR)in an acid electrolyte.The PtCu1.60/C exhibits an 8.9-fold enhanced mass activity(1.42 A·mgPt^(−1))over that of commercial Pt/C(0.16 A·mgPt^(−1)).The PtCu1.60/C exhibits 140,000 cycles durability without activity decline and surface PtCu cluster stability owing to unique structure derived from the matrix and epitaxial growth pattern,which effectively prevents the agglomeration of clusters and loss of near-surface active sites.Structure characterization and theoretical calculations confirm that Pt-rich PtCu clusters favor ORR activity and thermodynamic stability.In room-temperature polymer electrolyte membrane fuel cells,the PtCu1.60/C shows enhanced performance and delivers a power density of 154.1/318.8 mW·cm^(−2)and 100 h/50 h durability without current density decay in an air/O_(2)feedstock.

Supramolecular systems for bioapplications:recent research progress in China

Supramolecular systems feature dynamic,reversible and stimuli-responsive characteristics,which are not easily achieved by molecular entities.The last decade has witnessed tremendous advances in the investigations of supramolecular systems for various bioapplications,which include drug delivery,anticancer therapy,antibacterial therapy,photodynamic therapy,photothermal therapy,combination therapy,antidotes for residual drugs or toxins,and bioimaging and biosensing.Host-guest chemistry has played a key role in the development of such bioactive supramolecular systems,and natural macrocycles(such as cyclodextrins),synthetic macrocycles(such as calixarenes,cucurbit[n]urils,and pillararenes),and porous framework polymers(such as supramolecular organic frameworks and flexible organic frameworks)have been most successfully used as hosts to build different kinds of host-guest systems for attaining designed biofunctions.The self-assembly of rationally designed amphiphilic molecules,macromolecules and polymers represent another important approach for the construction of supramolecular architectures with advanced biofunctions.In this review,we summarize the important contributions made by Chinese researchers in this field,with emphasis on those reported in the past five years.

表面组成和应变可调的PtCu八面体纳米合金促进甲醇和乙醇电催化性能（英文）

本文介绍了一种以卤素离子(Br-或/和I-)为成分调变剂制备组成和应变可调的PtCu八面体纳米合金的简便方法.由于纳米合金化所产生的配位效应、协同效应和应变效应, PtCu八面体纳米合金在碱性介质中对甲醇和乙醇电氧化表现出优于商业Pt黑的催化性能.在这些PtCu八面体纳米合金中,优化的Pt59Cu41八面体纳米合金具有较高的催化活性和耐久性.对于甲醇氧化, Pt59Cu41八面体的比活性/质量活性为20.25 mAcm^-2/3.24Amg^-1Pt,分别是商业铂黑的6.64/5.3倍.对于乙醇氧化, Pt59Cu41八面体的比活性/质量活性为34.84 m A cm^-2/5.58 A mg^-1Pt,分别是商业铂黑的9.16/7.34倍.利用原位傅立叶变换红外光谱技术,对甲醇/乙醇氧化反应中的中间物种和产物进行了检测,并探讨了Pt59Cu41八面体催化活性和耐久性较好的原因,同时解释了在碱性介质中甲醇氧化耐久性优于乙醇的原因.本文对探索制备高性能的碱性甲醇/乙醇燃料电池纳米电催化剂具有一定的科学意义.

Low-coordinated surface sites make truncated Pd tetrahedrons as robust ORR electrocatalysts outperforming Pt for DMFC devices

Developing highly stable and active non-Pt oxygen reduction reaction(ORR)electrocatalysts for power generation device raises great concerns and remains a challenge.Here,we report novel truncated Pd tetrahedrons(T-Pd-Ths)enclosed by{111}facets with excellent uniformity,which have both low-coordinated surface sites and distinct lattice distortions that would induce“local strain”.In alkaline electrolyte,the T-Pd-Ths/C achieves remarkable ORR specific/mass activity(SA/MA)of 2.46 mA·cm^(−2)/1.69 A·mgPd^(−1),which is 12.3/16.9 and 10.7/14.1 times higher than commercial Pd/C and Pt/C,respectively.The T-Pd-Ths/C also exhibits high in-situ carbon monoxide(CO)tolerance and 50,000 cycles durability with an activity loss of 7.69%and morphological stability.The rotating ring-disk electrode(RRDE)measurements show that a 4-electron process occurs on T-PdThs/C.Theoretical calculations demonstrate that the low-coordinated surface sites contribute largely to the enhancement of ORR activity.In actual direct methanol fuel cell(DMFC)device,the T-Pd-Ths/C delivers superior open-circuit voltage(OCV)and peak power density(PPD)to commercial Pt/C from 25 to 80℃,and the maximum PPD can reach up to 163.7 mW·cm−2.This study demonstrates that the T-Pd-Ths/C holds promise as alternatives to Pt for ORR in DMFC device.

高效率钙钛矿太阳电池的界面修饰及其研究进展（英文）

有机-无机杂化钙钛矿由于其优异的电学及光学性质,成为制备太阳电池吸光层的理想材料.无论反式还是正式结构的钙钛矿太阳电池,均包含以下几个关键界面:电极/电子传输层界面、电子传输层/钙钛矿界面、钙钛矿/空穴传输层界面、空穴传输层/电极界面.这些界面的性质对于电池性能至关重要,因为激子的形成、分离及复合都直接决定于这些界面.此外,器件的稳定性也受界面性质的影响.因此,界面电荷转移以及相应的界面修饰对于制备高效率、高稳定性电池器件具有重要助益.本论文将侧重综述近期在钙钛矿电池领域关于界面修饰问题的重大突破与进展.