Electrochemical reduction of carbon dioxide to produce formic acid coupled with oxidative conversion of biomass

Electrochemical reduction of CO_(2)(CO_(2)RR)has become a research hot spot in recent years in the context of carbon neutrality.HCOOH is one of the most promising products obtained by electrochemical reduction of CO_(2) due to its high energy value as estimated by market price per energy unit and wide application in chemical industry.Biomass is the most abundant renewable resource in the natural world.Coupling biomass oxidative conversion with CO_(2)RR driven by renewable electricity would well achieve carbon negativity.In this work,we comprehensively reviewed the current research progress on CO_(2)RR to produce HCOOH and coupled system for conversion of biomass and its derivatives to produce value-added products.Sn-and Bi-based electrocatalysts are discussed for CO_(2)RR with regards to the structure of the catalyst and reaction mechanisms.Electro-oxidation reactions of biomass derived sugars,alcohols,furan aldehydes and even polymeric components of lignocellulose were reviewed as alternatives to replace oxygen evolution reaction(OER)in the conventional electrolysis process.It was recommended that to further improve the efficiency of the coupled system,future work should be focused on the development of more efficient and stable catalysts,careful design of the electrolytic cells for improving the mass transfer and development of environment-friendly processes for recovering the formed formate and biomass oxidation products.

Transforming liquid flow fuel cells to controllable reactors for highlyefficient oxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid at low temperature

Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild conditions.This LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to air.The reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of electrons.For a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism.

<i>Drymaria cordata</i>(Linn.) Willd (Caryophyllaceae): Ethnobotany, Pharmacology and Phytochemistry

In the present paper the isolation and characterization of seven major glycolipid classes (stigmasterol, acylated stigmasteryl glucoside, stigmasteryl glucoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, cerebroside and glucocerebroside) from Drymaria cordata (Linn.) Willd (Caryophyllaceae Family) are reported after an attempt has been made to congregate the traditional and pharmacological studies done on this important medicinal plant. Drymaria cordata is a weak spreading herb found widely dispersed in damp places all over the tropics of Africa, Asia and the Americas. There are many reports on its folk and traditional uses that include snake bite, skin diseases, peptic ulcer, headaches or nephritis, female infertility, sleeping disorders, convulsions, and febrile conditions in children. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities that include analgesic activity, antitussive activity, anxiolytic activity, antipyretic activity, antinociceptive activity, anti-inflammatory and antibacterial activities. The information summarized here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology, natural product chemistry and drug discovery related research.

Promoting and controlling electron transfer of furfural oxidation efficiently harvest electricity,furoic acid,hydrogen gas and hydrogen peroxide

Conventional chemical oxidation of aldehydes such as furfural to corresponding acids by molecular oxygen usually needs high pressure to increase the solubility of oxygen in aqueous phase,while electrochemical oxidation needs input of external electric energy.Herein,we developed a liquid flow fuel cell(LFFC)system to achieve oxidation of furfural in anode for furoic acid production with co-production of hydrogen gas.By controlling the electron transfer in cathode for reduction of oxygen,efficient generation of electricity or production of H_(2)O_(2)were achieved.Metal oxides especially Ag_(2)O have been screened as the efficient catalyst to promote the oxidation of aldehydes,while liquid redox couples were used for promoting the kinetics of oxygen reduction.A novel alkaline-acidic asymmetric design was also used for anolyte and catholyte,respectively,to promote the efficiency of electron transfer.Such an LFFC system achieves efficient conversion of chemical energy of aldehyde oxidation to electric energy and makes full use the transferred electrons for high-value added products without input of external energy.With(VO_(2))_(2)SO_(4)as the electron carrier in catholyte for four-electron reduction of oxygen,the peak output power density(Pmax)at room temperature reached 261 mW/cm^(2)with furoic acid and H_(2)yields of 90%and 0.10 mol/mol furfural,respectively.With anthraquinone-2-sulfonate(AQS)as the cathodic electron carrier,Pmaxof 60 mW/cm^(2)and furoic acid,H_(2)and H_(2)O_(2)yields of 0.88,0.15 and 0.41 mol/mol furfural were achieved,respectively.A new reaction mechanism on furfural oxidation on Ag_(2)O anode was proposed,referring to one-electron and two-electron reaction pathways depending on the fate of adsorbed hydrogen atom transferred from furfural aldehyde group.

Study of heavy metal speciation in branch sediments of Poyang Lake

This study concentrates on the environmental pollution level of sediments in the six branches of Poyang Lake, the biggest fresh water lake in China. This is the first systematic report on the speciation analysis of heavy metals （Cu, Co, Cd, Pb, and Ni） in the six branches of the lake. A reported analytical procedure involving a five-step sequential extraction is used for the partition of particulating heavy metals. The sediment samples are analyzed using flame atomic absorption spectroscopy （FAAS）. Experimental results obtained from five replicate samples of fluvial bottom surface sediments at the sampling points demonstrated that the relative standard deviation of the sequential extraction procedure was generally better than 10% （Cd except）. The average extracted contents of the five elements, analyzed after all five steps, are found to be （mg/kg） for Cu： 26.89, Co： 16.25, Cd： 1.08, Pb： 37.98, and Ni： 20.46. The content of the exchangeable species was generally lower. Except Cu, the percentage of the species bond to organic matter was lower than 20%. The fractions containing the most metal for Cu, Co, and Ni were the residues （52.26%, 45.28%, and 74.82%, respectively）.

Application of novel sol-gel composites on magnesium alloy

Application o f defect-free,adherent,and corrosion protective sol-gel film on the magnesium alloys is generally difficult.In this study,two novel sol-gel/conversion coating composites were successfully deposited on AM60B magnesium alloy in order to provide sufficient protection against the corrosion.The first composite(Ti-Zr/hybrid)was obtained via combination o f a hybrid sol-gel film(synthesized by mixing tetraethoxysilane(TEOS),and 3-glycidyloxypropyl-trimethoxysilane(GPTMS))as outer layer and Ti-Zr conversion coating as primer.Also,the second composite(Ti-Zr/PTMS)was applied in a similar manner by combination o f phenyl-trimethoxysilane(PTMS)so lgel film with the Ti-Zr conversion coating.The morphology and elemental composition of the Ti-Zr conversion film were assessed by the Scanning Electron Microscopy(SEM)and Energy Dispersive X-ray Spectroscopy(EDS),respectively.A cracky conversion film was applied on the alloy surface after immersion in the Ti-Zr conversion coating bath which was mainly composed of MgO,T i02,Zr02,and MgF2 compounds.Uniform,but not-adherent PTMS and hybrid sol-gel films(pure sol-gel films)with obvious defects were directly deposited onto the magnesium alloy without the Ti-Zr pretreatment which were morphologically characterized by the SEM.However,formation o f relatively uniform and completely defect-free Ti-Zr/hybrid and Ti-Zr/PTMS composites after using the Ti-Zr conversion coating as pretreatment was revealed by the SEM observations.In addition,the defects of the Ti-Zr conversion coating were completely filled by the sol-gel layers.The Ti-Zr/PTMS and Ti-Zr/hybrid composite coatings were provided much better corrosion protection capacity than the pure PTMS and hybrid sol-gel films,respectively which was confirmed by the Electrochemical Impedance Spectroscopy(EIS)and Potentiodynamic Polarization(PDP)examinations in 0.05 M NaCl solution.

镁合金表面含纳米金刚石的溶胶凝胶耐腐蚀涂层

在镁合金表面涂覆含不同比例羟基化纳米金刚石(HND)颗粒的溶胶凝胶防腐蚀涂层。加入0.01%、0.02%和0.05%(质量分数)HND颗粒后溶胶凝胶涂层中的微缺陷完全消失。AFM分析表明,加入0.005%和0.02%的HND颗粒后,溶胶凝胶层的平均粗糙度从约6.7 nm分别增加到16.1 nm和20.2 nm。在Harrison溶液中分别浸泡15、30、60和120 min后,用电化学阻抗谱(EIS)技术测试涂层的耐蚀性。加入不同浓度的HND颗粒可显著提高溶胶凝胶涂层的耐蚀性,并在0.01%时获得最佳结果。通过动电位极化试验验证电化学阻抗谱实验的结果。耐腐蚀性的增强是由于涂层的致密性(由于基体与HND颗粒产生化学作用)、腐蚀溶液曲折扩散路径的形成以及纳米颗粒对缺陷的填充。然而,随着纳米颗粒含量的增加,HND对耐腐蚀性的有利影响逐渐减弱。最后,对腐蚀实验后的溶胶凝胶纳米复合涂层的显微形貌进行研究。

酸性介质中N,N′-双(2-亚甲基吡啶)-1,2-亚氨基乙烷对AZ91D镁合金的腐蚀抑制作用(英文)

采用电化学方法研究N,N′-双(2-亚甲基吡啶)-1,2-亚氨基乙烷(BPIE)Schiff碱在0.010 mol/L HCl溶液中对AZ91D镁合金的腐蚀抑制作用。动电位极化曲线表明,BPIE Schiff碱是一种混合型缓蚀剂。电化学阻抗谱(EIS)测量证实了BPIE的腐蚀抑制作用。随着缓蚀剂浓度的增加,由于有更多的缓蚀剂吸附在AZ91D镁合金表面,电荷转移阻力减小,双电层电容减小。电化学噪声(EN)分析获得的数据在时间和频率域与EIS和极化曲线所得结果表现出良好的一致性。采用扫描电子显微镜(SEM)、X射线衍射(XRD)和能量色散X射线(EDX),研究BPIE的缓蚀作用。SEM照片显示,在存在BPIE的情况下,AZ91D合金表面的腐蚀损伤得到减轻。XRD分析显示,在存在BPIE的情况下,对应于富镁α相的谱峰强度增大,表明合金样品的腐蚀程度低。EDX分析也证实了BPIE的缓蚀作用。此Schiff碱化合物通过物理吸附在合金表面,吸附行为遵循Langmuir等温吸附模型。

AM60B镁合金防腐蚀Ce-V/溶胶-凝胶复合涂层的应用

研究AM60B镁合金表面复合涂层的应用,该涂层由铈-钒转化膜和混合溶胶-凝胶层组成。扫描电镜和X射线能谱分析显示铈-钒转化膜存在开裂结节结构,该转化膜由氧、铈、钒和镁原子组成。转化膜中的裂纹被致密无缺陷的混合溶胶-凝胶薄膜密封。在Harrison溶液中进行电位极化和电化学阻抗测试,结果表明铈-钒转化膜对镁合金提供了很小的防腐保护,然而复合涂层显著增大了镁合金的抗腐蚀性。通过密封铈-钒转化膜的裂缝,溶胶-凝胶膜对合金防护和阻碍腐蚀起到了很大的作用。极化测试后采用扫描电子显微镜验证了电化学测试结果。

Kinetics of Formic Acid-autocatalyzed Preparation of Performic Acid in Aqueous Phase

Performic 酸(PFA ) 是在化学处理使用的氧化剂，合成并且漂白。宏 PFA 的合成，水解作用和分解的运动模型经由蚁的 acid-autocatalyzed 反应被调查。PFA 合成和水解作用的内在的激活精力是 75.2 kJ。

Lignocellulosic biomass as sustainable feedstock and materials for power generation and energy storage

Lignocellulosic biomass has attracted great interest in recent years for energy production due to its renewability and carbon-neutral nature.There are various ways to convert lignocellulose to gaseous,liquid and solid fuels via thermochemical,chemical or biological approaches.Typical biomass derived fuels include syngas,bio-gas,bio-oil,bioethanol and biochar,all of which could be used as fuels for furnace,engine,turbine or fuel cells.Direct biomass fuel cells mediated by various electron carriers provide a new direction of lignocellulose conversion.Various metal and non-metal based carriers have been screened for mediating the electron transfer from biomass to oxygen thus generating electricity.The power density of direct biomass fuel cells can be over 100 mW cm^(-2),which shows promise for practical applications.Lignocellulose and its isolated components,primarily cellulose and lignin,have also been paid considerable attention as sustainable carbonaceous materials for preparation of electrodes for supercapacitors,lithium-ion batteries and lithium-sulfur batteries.In this paper,we have provided a state-of-the-art review on the research progress of lignocellulosic biomass as feedstock and materials for power generation and energy storage focusing on the chemistry aspects of the processes.It was recommended that process integration should be performed to reduce the cost for thermochemical and biological conversion of lignocellulose to biofuels,while efforts should be made to increase efficiency and improve the properties for biomass fuelled fuel cells and biomass derived electrodes for energy storage.

低温制备镁合金无预处理Ni-P涂层（英文）

在低温下用电化学促进化学镀(EPEP)在AM60B镁合金上制备无预处理Ni-P涂层,并用SEM、AFM、EDS和XRD等技术对涂层进行表征。在阴极电流密度为4m A/cm^2、温度为50°C的条件下获得致密、均匀和中等磷含量的Ni-P涂层,其显微组织为晶态-无定型的混合态。在相同的化学镀条件下,但不施加阴极电流,合金表面形成了岛状的镍团簇镀层。在3.5%NaCl腐蚀电解液中进行电化学检测,发现EPEP镀后镁合金的耐蚀性有了明显提高。显微电镜观察进一步证实了电化学测试的结果,涂层的厚度、显微硬度、孔隙度及粘结强度均合格。

Corrosion behavior of sintered zinc-aluminum coating in NaCl solution

Sintered zinc aluminum coating (SZAC) was prepared using zinc flakes, aluminum flakes and CrO 3 as main raw materials. The corrosion behavior of SZAC in 3.5%NaCl solution was studied by means of SEM, EDS, EIS and so on. Results indicate that aluminum corroded in advance of zinc to produce speculate or spherical substances, which attaches to SZAC and adds mass to it. Corrosion production passivates metal powders in SZAC, causes E corr of SZAC to increase gradually, and causes the arising of the third time constant in EIS, which corresponds to the insulation of corrosion production.

AZ91镁合金在冷却系统中的耐腐蚀性(英文)

运用电化学方法研究一种水杨酸Schift碱化合物(Salcn)对AZ91镁合金在30%乙二醇水溶液(30%EG/W)中的腐蚀行为的抑制作用。用扫描电镜观察合金在30%乙二醇水溶液(30%EG/W)中的腐蚀前、后的形貌。在室温下,添加这种水杨酸Schift碱化合物对AZ91镁合金的腐蚀抑制作用不明显,但在高温下,由于合金表面化学吸附了抑制剂而使其耐腐蚀性得到增强;随着抑制剂浓度的增加,镁合金表面吸附更多的抑制剂,从而使抑制作用的增强。

Ion-ion reactions for charge reduction of biopolymer at atmospheric pressure ambient

Extractive electrospray ionization source （EESI） was adapted for ion-ion reaction, which was demonstrated by using a linear quadrupole ion trap mass spectrometer for the first ion-ion reaction of biopolymers in the atmospheric pressure ambient.

Corrosion protection and mechanical properties of the electroless Ni-P-MOF nanocomposite coating on AM60B magnesium alloy

Al-based MIL-53 MOF nanostructure was synthesized hydrothermally and then co-deposited in the electroless nickel coating on AM60B magnesium alloy using Zr pretreatment as an eco-friendly underlayer.The MIL-53(Al)nanostructure was synthesized in the form of layered semi-cube crystals with the surface area and mean pore diameter of 985.72 m^(2)g^(-1) and 2.00 nm,respectively.The SEM images captured with two various zooming scales from the surface of the plain and MOF containing electroless layers showed cauliflower-like morphology with even distribution of nodule size.Also,the sub-grains of the plain coating disappeared after incorporation of the MOF.Although,both the normal and nanostructure-containing electroless layers have crystalline-amorphous structure,but the nanocomposite coating showed less crystallinity.The average surface roughness of the plain electroless coating was about 309 nm,which decreased to about 222 nm after incorporation of the MOF.The XRD patterns showed that the characteristic peak of Ni broadened after incorporation of the MOF,probably due to the decreasing of the crystallinity.For the heat-treated normal and MOF containing coatings at 200℃ no phase transition takes place,but new peaks appeared for heat-treated coatings at 400℃ due to the crystallization and second-phase precipitation.The results of the EIS tests showed an increase in the amount of the charge transfer resistance(from 19 to 29 kΩcm^(2))after addition of the MOF,which means an improvement in the corrosion resistance.Also,low Jcorrof the composite coating represents its higher corrosion resistance with respect to the plain coating.The micro-hardness values of the composite coating before and after the heat treatment were higher than the plain coating.Also,the Ni-P-MOF coating has a lower wear rate both before and after the heat treatment due to an improvement in its micro-hardness.

Effect of Pd ions in the chemical etching solution

The acrylonitrile-butadiene-styrene （ABS） surface was etched by dipping it into chromic acid-sulfuric acid containing a trace amount of palladium. The surface roughness, activity, and valence bond were characterized by atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. The results showed that with the increase of Pd concentration in the etching solution the ABS surface roughness reduced. The ratio of O to C increases and forms a large amount of O=C？O functional groups by dipping into Pd contained etching solution, thus the amount of colloids palladium adsorption increases. The carboxyl group acts as the ad- sorption site for the Pd/Sn catalyst.

电化学噪声法在线评估化学沉积速率（英文）

采用连续噪声电阻计算(CNRC)技术在线测定经锆预处理后镁合金的化学镀镍速率。为此,计算化学镀液中预处理合金表面的噪声电阻(R_n)随时间的变化。采用能量色散X射线谱仪(EDS)和扫描电镜(SEM)技术对CNRC结果进行解释。同时,用动电位极化法和重量法测定同一时间区间内的化学沉积速率,并与CNRC结果进行比较。R_n随施镀时间的变化表明,化学镀是由具有不同沉积速率的几个阶段组成的。由于极化法在线监测沉积速率的局限性,CNRC结果和极化法的结果并不一致。然而,重量法的结果与CNRC结果完全一致。因此可以认为CNRC是一种合适的化学沉积速率在线评估工具。

Combining the 8-hydroxyquinoline intercalated layered double hydroxide film and sol-gel coating for active corrosion protection of the magnesium alloy

8-hydroxyquinoline(8-HQ)intercalated layered double hydroxides(LDH)film as underlayer and sol-gel layer was combined for active corrosion protection of the AM60B magnesium alloy.The LDH,LDH/sol-gel,and LDH@HQ/sol-gel coatings were analyzed using the scanning electron microscopy(SEM),field emission scanning electron microscopy(FESEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),atomic force microscopy(AFM),and electrochemical impedance spectroscopy(EIS)methods.The SEM images showed that the surface was entirely coated by the LDH film composed of vertically-grown nanosheets.The same morphology was observed for the LDH/sol-gel and LDH@HQ/sol-gel coatings.Also,almost the same topography was observed for both composite coatings except that the LDH@HQ/sol-gel coating had relatively higher surface roughness.Although the LDH film had the same impedance behavior as the alloy sample in 3.5wt%NaCl solution,its corrosion resistance was much higher,which could be due to its barrier properties as well as to the trap-ping of the chloride ions.Similar to the LDH film,the corrosion resistance of the LDH/sol-gel composite diminished with increasing the ex-posure time.However,its values were much higher than that of the LDH film,which was mainly related to the sealing of the solution path-ways.The LDH@HQ/sol-gel composite showed much better anti-corrosion properties than the LDH/sol-gel coating due to the adsorption of the 8-HQ on the damaged areas through the complexation.

Toxicological studies for some agricultural waste extracts on mosquito larvae and experimental animals

Objective:To evaluate some agricultural waste extracts as insecticide and their effects on enzyme activities in liver and kidney of male mice.Methods:The insecticidal activity of five tested compounds(one crude extract and 4 waste compounds) was bioassay against the 3rd instars of the Culex pipiens(Cx.pipiens) larvae in the laboratory.The LC_(50) values of eucalyptol,apricot kernel.Rice bran,corn,black liquor and white liquor are 91.45.1166.1,1203.3.21449.65.4025.78 and 6343.18 ppm,respectively.Selection of the compounds for the subsequent studies was not only dependent on LC_(50) values but also on the persistence of these wastes products on large scale.Results:White and black liquor did not produce any gross effect at 200 mg/Kg body weight.No apparent toxic symptoms were observed in tested animals during the whole period of the experimenl which run out for 14 days.No statistically significance was observed in the enzyme choliuesterase activity,the activities of liver enzymes and kidney function in treated mice with black and while liquors.While,no and slighl inhibition was observed after the 2weeks ol treatment period with deltamethrin and lenilrothion reached to about 24%in plasma cholinesterase enzyme activity.Significantly increase in the activities ol liver enzymes and kidney function in treated mice with deltamethrin and fenitrothion.Conclusions:Black liquor can be used efficiently In control Cx.pipiens larvae under laboratory condition.Environmental problem caused by rice straw can be solved by converting the waste material to beneficial natural selective insecticide.