聚苯胺对2,5-二巯基-1,3,4-噻二唑电化学性质的影响

采用循环伏安法研究了聚苯胺（PAn）对2，5－二巯基－1，3，4－噻二唑（DMcT）电化学性质的影响。结果表明，在含0．1mol/LLiClO4和1．0mol/LHCl的乙腈溶液中，DMcT在玻碳电极上呈现2对明显的氧化还原峰。在PAn膜电极上则呈现1对氧化还原峰，并且可以与PAn形成DMcT／PAn复合物，复合物电极呈现的氧化还原的峰电位差较玻碳电极明显减小。因此认为PAn可以较大程度地提高复合物的导电性和电荷传递速度，对DMcT的氧化还原反应有显著的催化作用。     

Cerium–terbium mixed oxides as alternative components for three-way catalysts: a comparative study of Pt/CeTbOx and Pt/CeO2 model systems

By using a combination of oxygen buffering capacity (OBC) and oxygen storage capacity (OSC) measurements, the redox behaviour of a Pt/CeTbO_x catalyst is compared to that of a classic model TWC system: Pt/CeO₂. The results reported here show that the redox efficiency of the Pt/CeTbO_x catalyst is much better, especially at low temperature operation conditions such as those occurring during the cold start of engines. The catalyst containing terbium also shows lower ‘light-off’ temperatures for both methane and carbon monoxide oxidation.     

活性碳纤维氧化还原机理初探

在系统研究了活性碳纤维(ACF)氧化还原功能特征的基础上,进一步利用 X 射线衍射、红外、核磁及化学分析等技术,研究了 ACF 在惰性气氛中,非水介质中的氧化还原特性以及ACF 比表面积、表面官能团、水等对氧化还原性能的影响,从面对 ACF 的氧化还原反应机理提出了一些新的见解。实验结果表明,ACF 的氧化还原功能与空气(氧等)的吸附无关,主要是由于 ACF 表面的官能团所引起,其官能团不仅仅是≥C—OH,在有水存在时,≥C—H、甚至>C=O 也参与氧化还原反应,并且还是主要的反应.水对氧化还原容量影响甚大.ACF 的氧化还原容量随比表面积变化不大。     

Capacity balancing for vanadium redox flow batteries through continuous and dynamic electrolyte overflow

Journal of Applied Electrochemistry - The vanadium crossover through the membrane can have a significant impact on the capacity of the vanadium redox flow battery (VFB) over long-term...     

Reduction of dissolved oxygen in boiler water using new redox polymers

New polymers were used as catalysts for the removal of dissolved oxygen in boiler water. These polymers, based upon hydroquinone‐quinone redox system, were prepared by polymerization of methyl 4‐(2,5‐dimethoxybenzyl)cinnamate and copolymerization of this monomer with 4‐(4′‐vinylphenethyl)‐1,10‐phenanthroline. The resulting product was used to synthesize polymers containing transition metal ions. Nuclear magnetic resonance, infrared spectroscopy, and elemental analysis were achieved to characterize monomers and/or electron‐transfer polymers. These polymers were used for the removal of oxygen from water. It was shown that the oxygen content was reduced to less than 0.1 mg L^?1 in ～ 70 s. Based on the obtained results, the redox capacity of two polymers were determined. It was established that the poly‐4‐(2,5‐dihydroxybenzyl)cinnamic acid reached a redox capacity of 69.7 mg of O₂ per gram of polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Chemical dealloying pore structure control of porous copper current collector for dendrite-free lithium anode

Journal of Porous Materials - Lithium (Li) metal is considered to be the most ideal anode for rechargeable Li-metal batteries due to its high theoretical specific capacity and low redox potential....     

Activated carbon fibers as redox mediators for the increased reduction of nitroaromatics

Activated carbon fibers (ACFs) were used as redox mediators in the anaerobic chemical reduction of two model nitroaromatic compounds: 4-nitrophenol and 3-chloronitrobenzene. The effect of ACF chemical properties on the reduction of nitroaromatic compounds was measured by chemical oxidation of ACFs with 8 M nitric acid and thermal treatment at 700 °C under an inert atmosphere of hydrogen:helium (1:99%), before their use in batch experiments. The results show that ACFs are necessary to transform the nitroaromatic compounds to their corresponding aromatic amines, indicating the function of ACFs as redox mediators. Furthermore, the oxidation and thermal modification of ACFs clearly changes the redox properties of these materials, with the former being the better option to increase the concentration of quinone groups (1.68 times), and therefore the redox mediating capacity of ACFs (up to 1.38 times).     

Combination of redox capacity and double layer capacitance in composite electrodes through immobilization of an organic redox couple on carbon black

Carbon electrodes have been modified with 2-nitro-1-naphthol with the aim of producing composite supercapacitor electrodes, which make use of both the electric double layer (EDL) capacitance of high surface area carbon and the redox capacity (pseudocapacitance) of the organic compound. In situ FTIR and cyclic voltammetric data confirm literature reports of the reduction of 2-nitro-1-naphthol to 2-amino-1-naphthol and the subsequent oxidation of the o-aminonaphthol to the corresponding o-naphthaquinoneimine in aqueous acidic media. The measurements also show that the quinoneimine is not stable and hydrolized in sulphuric acid electrolyte to 1,2-naphthaquinone. The chemically highly reversible o-naphthaquinone/o-naphthahydroquinone couple remains immobilized on the carbon electrodes during redox cycling. The organic redox couple contributes a capacity of 35 mA h g⁻¹ of the bare carbon to the overall charge storage capability of the composite electrode. Surprisingly, it does not affect the capacitance of the electric double layer of the carbon. During 1000 charge/discharge cycles, the pseudocapacitance decreases by less than 20% in a normal large-volume electrochemical cell. Electrochemical impedance measurements show that the full capacity of the electrode is accessible at frequencies below 0.1 Hz.     

New Approach in Translational Medicine: Effects of Electrolyzed Reduced Water (ERW) on NF-κB/iNOS Pathway in U937 Cell Line under Altered Redox State

It is known that increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) can exert harmful effects, altering the cellular redox state. Electrolyzed Reduced Water (ERW) produced near the cathode during water electrolysis exhibits high pH, high concentration of dissolved hydrogen and an extremely negative redox potential. Several findings indicate that ERW had the ability of a scavenger free radical, which results from hydrogen molecules with a high reducing ability and may participate in the redox regulation of cellular function. We investigated the effect of ERW on H₂O₂-induced U937 damage by evaluating the modulation of redox cellular state. Western blotting and spectrophotometrical analysis showed that ERW inhibited oxidative stress by restoring the antioxidant capacity of superoxide dismutase, catalase and glutathione peroxidase. Consequently, ERW restores the ability of the glutathione reductase to supply the cell of an important endogenous antioxidant, such as GSH, reversing the inhibitory effect of H₂O₂ on redox balance of U937 cells. Therefore, this means a reduction of cytotoxicity induced by peroxynitrite via a downregulation of the NF-κB/iNOS pathway and could be used as an antioxidant for preventive and therapeutic application. In conclusion, ERW can protect the cellular redox balance, reducing the risk of several diseases with altered cellular homeostasis such as inflammation.     

Structural,morphological and thermal characterization of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) Cryogels: evaluation of water sorption potential and cytotoxicity

Cryogels are macroporous hydrogels which are synthesized through cryogelation method. In the present study cryogels of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) were synthesized by copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylonitrile (AN) monomers by redox polymerization using cryogelation technique. The synthesized cryogels were characterized by FTIR, SEM, XRD, DSC and TGA techniques. Different compositions of the cryogels were prepared by varying concentrations of the monomers and redox initiators in the feed mixture. These cryogels were then subjected to swelling studies and porosity determination. The swelling behavior was studied as function of concentration of the monomers, redox initiators, temperature, pH, and simulated biological fluids. The prepared cryogels were also characterized for their network parameters using water sorption data. The biocompatibility of P (HEMA-co-AN) cryogel was evaluated by in vitro cytotoxicity test. The results indicated that the P (HEMA-co-AN) cryogel had macroporous morphology and exhibited good water absorption capacity. Moreover, the cryogel was thermally stable and biocompatible in nature.     

Redox shuttles for safer lithium-ion batteries

Overcharge protection is not only critical for preventing the thermal runaway of lithium-ion batteries during operation, but also important for automatic capacity balancing during battery manufacturing and repair. A redox shuttle is an electrolyte additive that can be used as intrinsic overcharge protection mechanism to enhance the safety characteristics of lithium-ion batteries. The advances on stable redox shuttles are briefly reviewed. Fundamental studies for designing stable redox shuttles are also discussed.     

Effect of supports on the redox performance of pyrite cinder in chemical looping combustion

Chemical looping combustion (CLC) is a clean and efficient flame-free combustion technology,which combust the fuels by lattice oxygen from a solid oxygen carrier with inherent CO2 capture.The develop-ment of oxygen carriers with low cost and high redox performance is crucial to the whole efficiency of CLC process.As the solid by-product from the sulfuric acid production,pyrite cinder presented excellent redox performance as an oxygen carrier in CLC process.The main components in pyrite cinder are Fe2O3,CaSO4,Al2O3 and SiO2 in which Fe2O3 is the active component to provide lattice oxygen.In order to sys-tematic investigate the functions of supports (CaSO4,Al2O3 and SiO2) in pyrite cinder,three oxygen car-riers (Fe2O3-CaSO4,Fe2O3-Al2O3 and Fe2O3-SiO2) were prepared and evaluated in this study.The results showed that Fe2O3-CaSO4 displayed high redox activity and cycling stability in the multiple redox cycles.However,both Fe2O3-Al2O3 and Fe2O3-SiO2 experienced serious deactivation during redox reactions.It indicated that the inert Fe-Si solid solution (Fe2SiO4) was formed in the spent Fe2O3-SiO2 sample,which decreased the oxygen carrying capacity of this sample.The XPS results showed that the oxygen species on the surface of Fe2O3-CaSO4 could be fully recovered after the 20 redox cycles.It can be concluded that CaSO4 is the key to the high redox activity and cycling stability of pyrite cinder.     

Defective structure, oxygen mobility, oxygen storage capacity, and redox properties of RE-based (RE = Ce, Pr) solid solutions

Defective structures, surface textures, oxygen mobility, oxygen storage capacity (OSC), and redox properties of RE_0.6Zr_0.4O₂ and of RE_0.6Zr_0.4−xY_xO₂ (RE=Ce, Pr; x=0, 0.05) solid solutions have been investigated using X-ray diffraction (XRD), temperature-programmed desorption (TPD), temperature-programmed reduction (TPR), O₂−H₂ and O₂−CO titration, ¹⁸O/¹⁶O isotope exchange, CO pulsing reaction, and X-ray photoelectron spectroscopy (XPS) techniques. The effects of doping noble metal onto RE_0.6Zr_0.4−xY_xO₂ on oxygen mobility and surface oxygen activities have also been studied. Based on the experimental outcomes, we conclude that: (i) a Pr-based solid solution has better redox behavior than a Ce-based one; (ii) incorporation of yttrium ions in the lattices of CZ and PZ solid solutions could result in an enhancement in oxygen vacancy concentration, Ce⁴⁺/Ce³⁺ and Pr⁴⁺/Pr³⁺ redox properties, lattice oxygen mobility, and oxygen storage capacity; and (iii) doping the noble metal (Rh, Pt, and Pd) onto RE-based solid solution has positive effect on the properties concerned in this work.     

V(Ⅲ)-V(Ⅳ)电解液的化学合成及性能

钒电池是一种高效储能装置,钒电池电解液直接影响电池性能。本文以V2O3、V2O5和H2SO4为原料,化学合成了用于钒电池的V(Ⅲ)-V(Ⅳ)电解液,研究了无水乙醇与焦磷酸钠作为添加剂对电解液稳定性和电化学活性的影响。实验结果表明,当V2O3/V2O5质量比为7.2∶1时,可以得到V(Ⅲ)/V(Ⅳ)离子浓度比为1.0的电解液;添加剂的加入能提高电解液的稳定性和电化学反应活性。     

Study on the chemical synthesis and the performance of V(Ⅲ)-V(Ⅳ) electrolyte

钒电池是一种高效储能装置,钒电池电解液直接影响电池性能。本文以V2O3、V2O5和H2SO4为原料,化学合成了用于钒电池的V(Ⅲ)-V(Ⅳ)电解液,研究了无水乙醇与焦磷酸钠作为添加剂对电解液稳定性和电化学活性的影响。实验结果表明,当V2O3/V2O5质量比为7.2∶1时,可以得到V(Ⅲ)/V(Ⅳ)离子浓度比为1.0的电解液;添加剂的加入能提高电解液的稳定性和电化学反应活性。     

Effect of Simulated Thermo-Degradation on the Carotenoids, Tocopherols and Antioxidant Properties of Tomato and Paprika Oleoresins

Color quality is the economical key factor for oily extracts, also referred to as oleoresins, obtained from carotenogenic fruits and vegetables for application in foodstuffs. However, this organoleptic property is not the only attribute as carotenoids develop some bioactive actions, which provide a beneficial effect on health. It has been suggested that reaching some oxidation level during processing enhances the antioxidant activity of phytochemicals, including carotenoids, so that knowledge of the impact of thermal processing in the redox state and antioxidant activity is significant. During thermal degradation of carotenoids in tomato and paprika oleoresins the coloring content, redox state and antioxidant capacity were evaluated. The lipid profile and tocopherol content were similar in both oily extracts but significant differences were observed on functional properties derived from carotenoid activity. The initial antioxidant capacity was similar for both carotenoid extracts, tomato oleoresin kept higher antioxidant capacity values (DPPH test) than paprika oleoresin, although the degradation rate was significantly higher for lycopene, while carotenoids of paprika oleoresin degraded slowly. Paprika oleoresin showed a higher antioxidant activity (hydrogen peroxide test) than tomato oleoresin. Carotenoid degradation products may participate on radical scavenging reactions but efficiency depends on the radical species and structure of degradation products produced during thermal degradation.     

钒流电池负极电解液改性研究

全钒离子氧化还原液流电池(VRB)作为二次储能电池,具有循环寿命长、容量大、自放电小、污染小以及结构简单等优点,受到国内外研究者的广泛关注。但是VRB电解液仍然存在钒离子浓度过低、稳定性较差以及电化学反应速率低等问题,使VRB的应用受到限制。通过循环伏安法考察了添加剂尿素、草酸和酒石酸对负极电解液电化学反应速率的影响,发现合适浓度的尿素、草酸和酒石酸都可以部分增大其反应速率,提高电解液的可逆性,尤其以w(草酸)=0.5%效果最佳。对添加w(草酸)=0.5%的负极液进行了交流阻抗分析,发现草酸主要是降低了电化学反应电阻。最后通过电位滴定法研究了添加剂对负极液稳定性的影响,得出草酸和酒石酸都可以提高电解液稳定性的结论。     

全钒液流电池充电/放电过程模型

建立全钒液流电池充电/放电过程模型,描述钒离子在离子传导膜中渗透产生的自放电现象对电池过程影响,反映电解液中不同价态钒离子浓度随时间变化规律,以及电池开路电压、端电压的时间依存性。通过与实验结果对比,数值模拟与实验结果保持良好一致性,验证所发展的数学模型的有效性。利用数值模拟再现实验结果,研究了充放电电流与电池容量的关系。结果表明：电池容量随电流的变化存在峰值。所建立的全钒液流电池过程模型,为液流电池储能系统的设计和操作提供依据。     

Seedless copper electroplating on Ta from a “single” electrolytic bath

An alternative approach for copper electroplating on Ta surface from a “single” injected bath is being described in this work. Copper electrodeposition over a thin TaN/Ta barrier was performed in a two-step process: (1) activation conducted by electrochemically reduction of Ta oxide from the TaN/Ta barrier at a negative potential of −2 V for a short period (“removal” step) and (2) copper electroplating performed in the invariable electrochemical bath by injecting a solution containing Cu-ions. Supplementary Cu plating is continued by shifting the applied potential to −1.2 V in the same electrolytic bath. It was also established that addition of low content (up to 10 ppm) dimercaptothiadiazole (DMcT) improves Cu nucleation and growth on Ta surface and allows a conformal features fillings. Copper layer deposited is characterized with an excellent adhesion to the Ta surface.