H2O2/[Hnmp]HCOO氧化苯并噻吩类硫化物的量子化学研究

针对质子型离子液体[Hnmp]HCOO在加入H₂O₂后生成的过氧化物[Hnmp]HCOOO氧化苯并噻吩（BT）、二苯并噻吩（DBT）和4,6-二甲基二苯并噻吩（4,6-DMDBT）的氧化脱硫反应,采用密度泛函理论DFT/B3LYP-D3方法考察了这三种硫化物的反应历程。首先通过几何优化得到了[Hnmp]HCOO和[Hnmp]HCOOO的稳定结构,然后考察了[Hnmp]HCOOO氧化BT、DBT和4,6-DMDBT的反应机理,寻找可能的过渡态、中间体,计算各步反应的能量变化。结果表明,[Hnmp]HCOOO先将硫化物氧化成亚砜,然后进一步氧化成砜;在氧化过程中,DBT的反应速率是三者中最快的,与文献的实验结果一致,且H₂O₂/[Hnmp]HCOO体系的脱硫效果优于传统的H₂O₂/HCOOH体系。     

高级氧化技术在印染废水处理的应用和前景研究

本文通过臭氧氧化法实验分析高级氧化技术对印染废水处理的应用原理。结果表明,使用高级氧化技术中的臭氧氧化法对印染废水的净化处理有显著的效果,其应用原理是臭氧能将废水中原有的部分有机物被氧化成CO2和H2O,另一部分有机物被氧化成易于生物降解的小分子有机物,使得整体COD降低,并在一定程度上降低废水的色度,从而实现废水的处理。在实际的印染废水处理应用中,还可以结合其他催化剂一起使用,或根据废水的水质情况选用其他高级氧化技术,实现印染废水的处理。     

Ti-MCM-41/次氯酸钠催化氧化脱除模型油中苯并噻吩的研究

采用水热法合成了介孔Ti-MCM-41分子筛,并通过X射线粉末衍射（XRD）,傅立叶变换红外光谱（FT-IR）,紫外−可见光漫反射光谱（DR UV-vis）以及BET氮气吸附−脱附等温线方法对合成的样品进行表征。以正庚烷−苯并噻吩模拟油,以Ti-MCM-41/NaClO为催化氧化体系,考察其催化氧化反应条件及动力学参数。结果表明当反应温度为308 K,反应时间为40 min,NaClO用量为3 mL,Ti-MCM-41用量为0.05 g,萃取剂乙腈用量为10 mL,脱硫率达68%;动力学分析表明苯并噻吩的氧化反应为一级反应,表观活化能Ea为56.55 kJ/mol。结果表明利用Ti-MCM-41/NaClO体系催化氧化脱硫是行之有效的。     

阴离子氧化还原反应对富锂锰基正极材料的影响及其改性策略北大核心CSCD

兼具高能量密度、高功率密度、长循环寿命性能的正极材料是当下电池储能材料研究的重点,也是储能市场的重要需求。富锂锰基正极材料(LRMO)因其极高的放电比容量(≥250 mAh/g)、较高的工作电压(4.2~4.5 V vs.Li/Li^(+))、低成本且环境友好等优点成为当下最具应用前景的正极材料之一。虽然金属阳离子和阴离子依次或同时进行的氧化还原反应使LRMO材料的容量超过了传统层状氧化物,但首次不可逆容量高、循环和倍率性能较差等一系列的问题阻碍了其工程化应用,这与材料中阴离子氧化还原反应紧密相关。本文首先介绍了LRMO材料的晶体结构,然后基于分子轨道理论,回顾了LRMO材料的能带结构与阴阳离子氧化还原反应的联系,总结了阴离子氧化还原反应对富锂锰基正极材料的影响,包括高容量、不可逆的氧流失、过渡金属离子迁移。同时,分别从过渡金属比例调节、表面修饰、离子掺杂三个方面总结了近些年国内外研究人员针对阴离子氧化还原反应造成的负面影响设计的改性策略。最后展望了LRMO材料理论研究与应用研究的大致方向。     

垃圾电厂脱酸塔臭氧脱硝工艺研究

采用臭氧协同半干法研究了垃圾电厂脱酸塔内的臭氧氧化过程,分析了降温过程、臭氧管道和喷嘴布置方式对混合流场的影响,对比了不同布置方案下的氧化效率,并分析了臭氧主管道高度对氧化效率的影响。结果表明：脱酸塔内喷入质量流量为0.2 kg/s的水后可以达到臭氧合适的反应区间,同时塔内温度降幅不大;在臭氧管道布置在上方、喷嘴向下喷入的方式下臭氧在塔内整体分布和流场较好;随着O₃/NO质量流量比由1增至3,在管道中央布置方式下氧化效率由38.12%提高到94.31%,在管道贯穿布置方式下氧化效率由38.66%提高到94.72%,氧化效率均逐渐提高,但其增速均逐渐减小;随着臭氧主管道下移,氧化效率有轻微波动,但大部分维持在94%～96%内。     

船舶尾气臭氧氧化-海水吸收的脱硫脱硝新工艺研究

通过模拟试验研究了臭氧氧化结合海水吸收同时脱除船用发动机排气中SO2和NO2的新工艺.在管式反应器内研究了反应温度、n(O3)/n(NO)(物质的量之比)、碳氢、SO2等对臭氧氧化NO的影响,并对模拟尾气进行了臭氧氧化结合海水吸收的脱硫脱硝试验.结果表明,n(O3)/n(NO)对臭氧氧化NO影响很大,NO氧化率随n(O3)/n(NO)呈线性增长,n(O3)/n(NO)为1,反应温度分别为常温、150℃和200℃时,NO氧化率分别达到99.0%、98.3%和98.1%;反应温度低于200℃时,温度对臭氧氧化NO影响很小,而当反应温度升至275℃时,NO氧化率明显下降,这与臭氧在较高温度下分解有关;SO2在O3/NO/SO2/N2/O2体系和O3/NO/C2H4/SO2/N2/O2体系中对臭氧氧化NO都没有影响;200℃以下,C2H4对臭氧氧化NO影响很小,而在275 ℃时,C2H4对臭氧氧化NO有一定促进作用;模拟尾气经臭氧氧化-海水吸收后,脱硫率为98.5%,n(O3)/n(NO)为1时的脱硝率为91.05,NO能耗为56.4 g、(kW·h).     

微气泡深度氧化技术治理VOCs的工艺原理与设计

本文介绍了用于治理VOCs的微气泡深度氧化技术,并对其深度氧化原理进行了研究分析,从臭氧特性、臭氧制备、臭氧自分解及臭氧的直接氧化角度做了阐述,对该项技术与设备中的设计要点进行了研究,使其能够有效处理废气中的VOCs,为进一步推广和应用该技术提供了理论依据。     

臭氧在烟气中氧化零价汞的量子化学研究

利用量子化学方法计算研究了臭氧在烟气中氧化零价汞的微观反应机理,采用MP2/SDD计算方法优化得到反应物、过渡态、中间体及产物的几何构型,并通过振动分析与IRC分析确定反应过渡态和中间体,在QCISD(T)/SDD水平上计算能量,同时进行零点能校正,计算了反应活化能,并采用经典过渡态理论(TST)计算反应的速率常数,拟算出反应的阿累尼乌斯表达式.结果表明,臭氧在烟气中产生的NO3、O3和NO2粒子对零价汞进行氧化的活化能分别为22.94 kJ/mol,53.34kJ/mol和168.23kJ/mol.通过活化能比较,得到3种粒子的氧化性强弱为:NO3＞O3＞NO2在298 K下,将计算获得的反应速率常数与文献数据进行比较,结果吻合较好.     

油气田含硫废水化学混凝-臭氧氧化复合处理工艺

对油气田含硫废水来源、组成及危害进行分析,提出化学混凝-臭氧氧化复合处理的工艺技术。通过单因素和正交实验,对化学混凝及臭氧氧化处理的影响因素进行分析,得到了优化的工艺条件：①采用化学混凝处理时,混凝剂选用HNJFZ混凝剂（加量为3500mg/L）,絮凝剂选用FASG絮凝剂（加量为15mg/L）,体系的pH值为8～9;②采用臭氧氧化深度处理时,臭氧浓度为60mg/L,氧化时间为40min,pH值为10.0左右。采用上述复合处理工艺条件对含硫废水进行处理验证。验证结果显示,含硫废水的水色清澈,CODCr由6346mg/L降至98.5mg/L,S2-浓度由132mg/L降至0.897mg/L,去除率分别达到98.4%和99.3%,可满足污水综合排放标准（GB8978—1996）的要求。     

高碱煤燃烧初期羧酸钠的迁移转化机理

基于密度泛函理论和过渡态原理,在M06-2X/6-311G(d)水平上研究了燃烧初期高碱煤羧酸钠的迁移转化机理,探讨了高碱煤基质中各种可能的单分子、双分子脱羧、脱碳、交联、自由基攻击的反应路径．计算结果表明,单分子脱羧释放二氧化碳为最有利的初级反应路径;羧酸钠和相关模型化合物(CM—COOH和CM—OH)在热解过程中发生的双分子脱羧反应需翻越的能垒较脱碳反应和交联反应的能垒低,即双分子脱羧最易进行;高碱煤基质中存在H自由基和甲基自由基并能够进入羧酸钠基,导致Na原子和NaCO2自由基的释放．     

Tuning the LUMO level of the acceptor to increase the open-circuit voltage of polymer-fullerene solar cells: A quantum chemical study

In the present study, semiempirical and density functional molecular orbital calculations are performed on fullerene derivatives with varying reduction potentials, successfully used as an electron acceptor in bulk heterojunction solar cells. The geometries of all the compounds were optimized with the semiempirical PM3 method. Density functional theory (DFT) single-point calculations, B3LYP/3-21G*, have been carried out with the aim to investigate the energy levels of the frontier orbitals. We have correlated the theoretical lowest unoccupied molecular orbital (LUMO) levels of different fullerenes with the open-circuit voltage of the photovoltaic device based on the blend of poly[2-methoxy-5-(3,7-dimethyloctyloxy)]–1,4-phenylenevinylene (MDMO–PPV) with the acceptor molecules. We have also investigated the influence of new substituents on the LUMO level of the parent fullerene showing the possibility to further increase the open-circuit voltage of the MDMO–PPV:fullerene device.     

Novel benzothiophene based catalyst with enhanced activity for glucose electrooxidation

Thiophene based heterocyclic compounds plays important roles in organic chemistry due to their unexpected properties. Herein, novel benzothiophene derivatives (6A-F) are synthesized via Sonogashira coupling, iodocyclization reaction, Suzuki-Miyaura coupling and condensation reactions. After characterization of design molecules, their glucose electrooxidation activities are investigated. Electrochemical measurements are performed by cyclic voltammetry, chrono amperometry, and electrochemical impedance spectroscopy in 1 M KOH +0.5 M C₆H₁₂O₆ solution. This results show that the highest performance organic-based catalysts is obtained as 0.729 mA/cm² (3.345 mA/mg) for the 2-(4-(2-pentylbenzo [b]thiophen-3-yl)benzylidene)malononitrile (6B). Furthermore, 6B catalyst is shown long term stability, the best current density value (1.151 mA cm⁻²), and the best transfer resistance load between organic-based catalysts. As a result, it is clear that these benzothiophene derivatives are promising organic based catalyst, an alternative to the expensive Pd and Pt based metal catalyst, for direct glucose fuel cell anode.     

Synthesis and photovoltaic properties of a low bandgap donor-acceptor alternating copolymer with benzothiadiazole unit

A new donor-acceptor alternating copolymer as the donor material of the active layer in polymer solar cells has been synthesized. The alternating structure consisted of dithieno[3,2-b:2′,3′-d]thiophene (DTT) donor unit and 5,6-bis(tetradecyloxy)benzo-2,1,3-thiadiazole (BT) acceptor unit. Both units were confirmed by ¹H NMR and elemental analysis. Since the BT unit has long alkyoxyl side chains, the polymer was soluble in common organic solvents. Optoelectronic properties of the copolymer (PDTTBT) were investigated and observed by UV-vis, photoluminescence (PL) spectra, and cyclic voltammogram (CV). UV-vis spectrum exhibited a broad absorption band in the range of 300-750 nm and a low bandgap of 1.83 eV. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of PDTTBT could be determined from the data of CV and UV-vis spectrum. Based on the ITO/PEDOT:PSS/PDTTBT:PCBM/Al device structure, the power conversion efficiency (PCE) under the illumination of AM 1.5 (100 mW/cm²) was 0.113%. It was found that PCE of 0.301% could be acquired under the annealing condition at 150 °C for 30 min. In addition, solar cells fabricated with the 1,8-octanedithiol (OT) additive in the mixture solvent or adding TiO_x optical spacer show efficiencies significantly improved over 15%.     

Quantum chemical studies of Li cation binding to polyalkyloxides

A quantum chemical study of the binding of Li⁺ cation to polyalkyloxides has been carried out. The lithium cation interaction with three polyalkyloxides (polyethylene oxide (PEO), polytrimethylene oxide (PTMO), and polypropylene oxide (PPO)) has been investigated using ab initio molecular orbital theory at the HF/6-31G^* level with molecular models for the polymers. Coordination by one to six oxygens was considered. In addition, higher level calculations were carried out using G3(MP2) theory for coordination of Li⁺ by one oxygen. For coordination of lithium by one oxygen, the binding energy ordering is PTMO>PPO>PEO, with PTMO having the largest lithium cation affinity. The same ordering is found for larger coordination numbers with the exception of coordination by six oxygens, where the ordering changes due to the steric interactions.     

Higher fullerenes as electron acceptors for polymer solar cells: A quantum chemical study

In the present study, we have used quantum chemical methods to study the energy levels of the frontier orbitals of higher fullerene derivatives (from C₇₀ to C₈₄ and having the same addend as in [6,6]-phenyl C₆₁-butyric acid methyl ester) with the aim to understand if they can be used as electron acceptors in bulk heterojunction polymer–fullerene solar cells. Higher fullerenes have a stronger and broader absorption compared to C₆₀ and they can improve the current output of the corresponding devices. The geometries of all the compounds were optimized with the density functional theory at the B3LYP/3-21G* level of calculation. The lowest unoccupied molecular orbital (LUMO) levels of the investigated compounds correlate well with the reduction potentials (obtained by cyclic voltammetry) of the already prepared species. We found that the LUMO level depends not only on the fullerene size (number of carbons of the cage) and constitutional isomer, but also on the position and, in some cases, the addend orientation. This issue should be considered because for a proper device operation, a well-defined LUMO is required. The position of the LUMO level of some higher fullerene derivatives can be suitable for low-bandgap polymers.     

柴油发动机臭氧助燃技术应用研究

通过对柴油发动机臭氧助燃机理分析,设计了臭氧发生器,并将其用于BF6M1015RC柴油发动机台架试验中。结果证明：臭氧参与柴油发动机的燃烧过程能起到节油和降低排放的双重效果。     

One-pot synthesis of ultrasmall PtAg nanoparticles decorated on graphene as a high-performance catalyst toward methanol oxidation

A one-pot synthesis method is utilized for the fabrication of ultrasmall platinum-silver nanoparticles decorated on graphene (PtAg/G) catalyst. This method has several advantages such as inexpensiveness, simplicity, low temperature, surfactant free, reductant free, being environmentally friendly and greenness. In this work, graphene and silver formate were dispersed in ultrapure water in an ultrasonic bath at 25 °C followed by through a galvanic displacement reaction; to prepare PtAg/G, PtCl₂ was added to the suspension under mild stirring condition. The morphology, crystal structure and chemical compositions of the as-fabricated PtAg/G and Pt/C catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Energy dispersive X-ray spectroscopy (EDS) techniques. Electrochemical techniques, including cyclic voltammetry (CV) and chronoamperometry (CA) measurements were used to analyze the electrochemical activity of the PtAg/G and Pt/C catalysts. The TEM images illustrate the uniform distribution of ultrasmall PtAg nanoparticles with the average size of 2–3 nm on the graphene nanosheets. The PtAg/G promoted the current density 2.46 times as much as Pt/C with a negative shift in onset oxidation potential and peak potential for oxidation reaction of methanol. Besides, the novel PtAg/G catalyst shows large electrochemically active surface area, lower apparent activation energy, and higher levels of durability in comparison to the Pt/C catalyst for the oxidation of methanol. The PtAg/G catalyst depicts extraordinary catalytic performance and stability to those of the Pt/C catalyst toward methanol oxidation in alkaline media.