生物乙醇重整制氢反应器

生物乙醇重整制氢是一种具有良好应用前景的制氢技术,是当前低碳能源领域的研究热点.发展生物乙醇重整制氢技术的关键是研发在低温下具有高活性和高选择性的新型重整催化剂,以及开发新式高效的催化反应器.本文着眼于反应器对生物乙醇重整制氢过程的影响,综述了国内外固定床反应器、微通道反应器和膜反应器等生物乙醇重整制氢反应器的研究现状...     

水蒸气重整生物质裂解油及其模型分子制氢*

随着能源枯竭和环境日益恶化,利用可再生的生物质裂解油或其模型分子重整制氢逐渐引起人们重视。本文结合国内外重整制氢的研究进展,从催化剂、反应过程和反应机理三个方面对生物质裂解油及其模型分子(乙醇、乙酸、乙二醇、丙三醇、葡萄糖和苯酚等)水蒸气重整制氢研究现状进行了回顾。在重整催化剂方面主要对贵金属和过渡金属催化剂的研究进展进行了总结,对一些新的重整过程如液相重整等也进行了介绍。在反应机理方面主要是对乙醇、乙酸、乙二醇和葡萄糖在重整反应中的反应路径进行了归纳。此外,对水蒸气重整反应中遇到的问题如积碳和副产物的产生等也进行了详细的分析,并对生物质制氢未来发展的方向进行了展望。     

甲烷催化二氧化碳重整制合成气反应研究进展*

本文参阅了甲烷催化二氧化碳重整制合成气反应研究方面50 余篇文献, 概述了近年来在该研究中催化剂活性组分选择、载体效应、助剂的作用、催化剂积炭行为和重整反应机理等方面的研究进展。     

太阳能甲烷重整反应中的催化活性吸收体

太阳能甲烷重整反应可实现太阳能的高温蓄存和天然气资源的优化利用而备受关注,催化活性吸收体是进行太阳能吸收利用和甲烷催化重整的关键而成为太阳能甲烷重整反应研究的热点。本文在简述催化活性吸收体构成的基础上,结合重整反应器/接收器的发展,具体介绍了以多孔氧化铝和碳化硅陶瓷、泡沫金属及管状阵列陶瓷(“porcupine”)为基体的催化活性吸收体及其在太阳能甲烷重整反应中的应用,进而根据国内外的研究基础,分析探讨了今后的研究重点和发展方向。     

甲烷二氧化碳重整制合成气钴基催化剂

温室效应是人类面临的巨大挑战,温室气体的转化利用因而成为广泛研究的热点和难点课题。甲烷二氧化碳重整,即干重整制合成气因为可以同时将两种温室气体(CH-4/CO_2)转化为可用于清洁能源生产的合成气(H_2/CO)而被认为是极具前景的先进技术。此技术目前仍未大规模工业化,其主要瓶颈在于尚未研发出合适的催化剂。过渡金属催化剂因其高活性和相对低廉的成本而被认为最具工业化前景,此前的研究主要集中在镍基催化剂,但是镍基催化剂易因表面积碳和金属烧结而快速失活。近年来,研究者发现钴基催化剂在甲烷二氧化碳重整中也具有良好的催化性能,并进行了初步的研究。本文将对钴基重整催化剂的研究现状进行简要综述。论文首先介绍了催化剂的活性组分、载体、助剂以及制备方法等对钴基催化剂重整性能的影响,接着阐述了钴基催化剂的重整反应机理以及积碳-消碳过程,最后对钴基重整催化剂的设计及未来研究方向进行了展望。     

微细腔内甲烷湿空气低温重整特性热力学分析

从理论上探讨低温(小于973K)、压力、空碳比及水碳比对重整特性及甲烷转化率的影响,以及各参数的合理取值范围;同时,对甲烷自热重整系统与无氧重整系统进行了性能对比.研究结果表明:微细腔在温度大于633K,反应压力小于0.10MPa,空碳(摩尔)比为2.0以及水碳摩尔比在1.0-2.5之间有利于甲烷自热重整反应的发生;自热重整与无氧重整体系相比,当甲烷质量流量一定时,有氧系统可以在较低的水碳比和较低的温度条件下获得较高的甲烷转化率和氢气产量.     

甲烷干气重整反应进展(英文)

系统地回顾和总结了二氧化碳重整反应的研究进展和现状,包括催化剂活性组分、载体、助剂以及催化剂制各方法等因素对催化剂性能的影响,同时对催化剂活性组分与反应中间体的结构与性能、反应机理和动力学行为及催化剂失活特性进行了细致的分析。大量研究表明金属镍是最富潜力的干气重整催化剂活性组分,而催化剂积炭是决定该反应能否工业化的关键因素。探索抑制催化剂积碳失活的有效途径是二氧化碳重整过程开发成功的关键。甲烷二氧化碳（干气）重整反应的研究和开发将提供一条天然气有效利用与温室气体减排的有效途径。     

甲烷临氧催化转化制合成气研究进展

作为烃类液化的最重要步骤,从天然气制合成气是近几十年催化科学研究的前沿和热点之一.结合笔者实验室的工作,本文介绍了国内外甲烷临氧催化转化制合成气的研究现状,对甲烷部分氧化、甲烷临氧二氧化碳重整、甲烷临氧水蒸气重整及甲烷-二氧化碳-水-氧气偶合重整进行了阐述和分析,综述了在催化剂体系、反应机理和工艺条件等方面近期取得的研究成果;并对甲烷临氧催化转化制合成气技术今后的研究重点及应用作了展望.     

甲醇水蒸汽催化重整过程的研究进展

甲醇水蒸汽重整是车载燃料电池较为理想的氢源,其中选择合适的催化剂又是重整反应的一个关键问题.本文综述了应用于甲醇水蒸汽重整反应的常用催化剂,如含Cu、Ni、Cr、Pd等,包括这些催化剂的催化性能、反应条件、产物分析等,并对部分催化剂的催化机理和动力学分析进行了概述.另外,还简要地介绍了应用于氧化水蒸汽重整反应的催化剂。     

橄榄石对甲苯催化重整反应的影响

在固定床反应器上,以甲苯为生物质气化焦油的模型化合物,对橄榄石以及其负载镍催化剂对甲苯裂解反应和甲苯/水蒸气重整反应的催化性能进行了研究,并对催化剂进行了SEM、BET、XRD、H₂-TPR等表征。结果表明,煅烧使原矿的物化特性发生改变,橄榄石对甲苯裂解反应和重整反应有一定的催化活性。而Ni的引入,使催化剂对甲苯裂解反应的活性有所降低,甲苯的转化率降低2.2%~9.8%;但催化剂对甲苯/水蒸气重整反应的活性升高,甲苯的转化率可高达97.0%,并且载镍橄榄石催化剂对甲苯/水蒸气重整反应有较强的稳定性。     

Photo-driven liquid crystal cell with high sensitivity

The photo-driven LC cell was assembled by sandwiching the liquid crystal material between two quartz or ITO plates covered with a 'command layer', which was fabricated from azobenzene-grafted ladder-like polysilsesquioxanes. The improved response sensitivity of the photo-driven cell, which means a lower threshold driving UV light intensity and a faster risetime, was achieved in two ways: pre-rubbing of the command surface and application of an assisting critical in-plane mode electric field. The response behaviour of the photo-driven cell was measured in situ and data were collected by computer. The results show that the risetime (4 s) under a weak UV intensity of 0.5 mWcm -2 is shorter than previously reported (several tens of seconds) under a greater UV intensity of 3-5 mWcm -2. The improved photo-driven LC cell holds out promise of potential applications in photo-addressing and photo-recording.     

Photo-driven liquid crystal cell with high sensitivity

The photo-driven LC cell was assembled by sandwiching the liquid crystal material between two quartz or ITO plates covered with a 'command layer', which was fabricated from azobenzene-grafted ladder-like polysilsesquioxanes. The improved response sensitivity of the photo-driven cell, which means a lower threshold driving UV light intensity and a faster risetime, was achieved in two ways: pre-rubbing of the command surface and application of an assisting critical in-plane mode electric field. The response behaviour of the photo-driven cell was measured in situ and data were collected by computer. The results show that the risetime (4 s) under a weak UV intensity of 0.5 mWcm -2 is shorter than previously reported (several tens of seconds) under a greater UV intensity of 3-5 mWcm -2. The improved photo-driven LC cell holds out promise of potential applications in photo-addressing and photo-recording.     

光驱动分子梭

分子梭在分子开关、分子逻辑门、信息存储等领域有着潜在的应用价值,是超分子化学领域的研究热点之一。本文综述了光驱动分子梭的研究进展：重点举例介绍了荧光光谱识别法和圆二色光谱识别法这两种识别光驱动分子梭位置状态的方法;阐述了构建光驱动轮烷分子梭的新型方法学,包括光驱动环糊精[2]轮烷和[1]轮烷分子梭的定向合成,举例介绍了光间接驱动的轮烷分子梭,以及光驱动[3]轮烷型分子梭和分子梭聚合物;举例说明了光驱动分子梭的功能性应用,用光驱动分子梭来模拟分子水平的逻辑门,研究光驱动分子梭体系中的能量传递机理,以及非溶液态的光驱动分子梭;并对分子梭今后的发展做了展望。     

Photo-driven optical oscillators in the kHz range based on push-pull hydroxyazopyridines

Push-pull azophenols are valuable target molecules for stable photo-driven optical oscillators. Hydroxyazopyridinium methyl iodide salts show oscillation frequencies up to 10 kHz with no signs of fatigue upon continuous work.     

Drastic difference in the photo-driven hydrogenation reactions of ruthenium complexes containing NAD model ligands

Successful control of photo-driven NAD(+)/NADH type hydrogenation reactions in ruthenium complexes has been accomplished by using a new NAD(+) model ligand with modulated distortion of the ligand taking advantage of the substituent effect.     

Pnictogen-Bridged Diphenyl Sulfones as Photoinduced Pnictogen Bond Forming Emission Motifs

In this study, pnictogen (Pn)-bridged diphenyl sulfones were synthesized as motifs for photoinduced dynamic rearrangement. The newly synthesized sulfones exhibited dual fluorescence at 298 K. Density functional theory calculations revealed that the longer-wavelength fluorescence was derived from the geometries after structural relaxation through photo-driven pnictogen bond formation between the O atom lone pair of the sulfonyl moiety and the antibonding orbital of the Pn−C bond. This is the first report on emission dynamics driven by pnictogen bond formation upon photoexcitation.     

电化学界面SERS光谱的密度泛函理论研究

运用量子化学密度泛函DFT理论和拉曼光谱研究了吡啶在过渡金属(Ⅷ族)和币族金属(IB族)表面吸附的成键机理及其拉曼光谱的变化规律.总结了作者研究组有关吡啶-金属SERS体系的研究,并从化学成键机理和光驱电荷转移机理两个方面探讨了电化学界面SERS谱峰的频率位移和增强效应,解释了实验观测到的SERS光谱随金属电极材料、激发光波长以及电极电位变化的现象.     

Plasmonic Cu Nanoparticles for the Low-temperature Photo-driven Water-gas Shift Reaction

The activation of water molecules in thermal catalysis typically requires high temperatures, representing an obstacle to catalyst development for the low-temperature water-gas shift reaction (WGSR). Plasmonic photocatalysis allows activation of water at low temperatures through the generation of light-induced hot electrons. Herein, we report a layered double hydroxide-derived copper catalyst (LD-Cu) with outstanding performance for the low-temperature photo-driven WGSR. LD-Cu offered a lower activation energy for WGSR to H₂ under UV/Vis irradiation (1.4 W cm⁻²) compared to under dark conditions. Detailed experimental studies revealed that highly dispersed Cu nanoparticles created an abundance of hot electrons during light absorption, which promoted *H₂O dissociation and *H combination via a carboxyl pathway, leading to the efficient production of H₂. Results demonstrate the benefits of exploiting plasmonic phenomena in the development of photo-driven low-temperature WGSR catalysts.     

Mesoporous silica nanospheres with the ability of photo-driven releasing sandela 803 for the application to wallpaper

Mesoporous silica nanospheres loaded with sandela 803 (S803@MS-S) are prepared for application to wallpaper. The nano-fragrance has high encapsulation efficiency and property of photo-driven release.     

Photo-Driven Iron-Induced Non-Oxidative Coupling of Methane to Ethane

Photo-driven CH₄ conversion to multi-carbon products and H₂ is attractive but challenging, and the development of efficient catalytic systems is critical. Herein, we construct a solar-energy-driven redox cycle for combining CH₄ conversion and H₂ production using iron ions. A photo-driven iron-induced reaction system was developed, which is efficient at selective coupling of CH₄ as well as conversion of benzene and cyclohexane under mild conditions. For CH₄ conversion, 94 % C₂ selectivity and a C₂H₆ formation rate of 8.4 μmol h⁻¹ is achieved. Mechanistic studies reveal that CH₄ coupling is induced by hydroxyl radical, which is generated by photo-driven intermolecular charge migration of an Fe³⁺ complex. The delicate coordination structure of the [Fe(H₂O)₅OH]²⁺ complex ensures selective C−H bond activation and C−C coupling of CH₄. The produced Fe²⁺ can be used to reduce the potential for electrolytic H₂ production, and then turns back into Fe³⁺, forming an energy-saving and sustainable recyclable system.