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钛基二氧化铅电催化电极的制备及电催化性能研究 总被引:32,自引:0,他引:32
以电沉积法制备了钛基PbO2电极,优化并确定了电极的制备工艺,以苯酚为目标有机物,考察了电极的电催化氧化性能,研究结果表明,该电极的电催化性能优于传统的DSA钛基RuO2电极。采用该电极,在10Ma/cm^2电流密度下通过0.72Ah电量后,可使100Ml、COD浓度为270mg/L的苯酚溶液中的苯酚完全分解,COD去除率为67.4%,单位电量COD降解量为0.254mgCOD/Ah,且电流效率随电流密度的增加而减小,初步研究了苯酚的电催化氧化机理,提出了苯酚的电催化氧化可能是由苯酚的直接电化学氧化为苯醌及苯醌的间接电化学氧化有机酸两部分组成。 相似文献
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利用可再生清洁能源将CO2转化为CO和其他小分子是合成含碳燃料的可观方法之一.间歇性可再生能源存储的重要策略之一是将二氧化碳进行电化学还原.选择具有高活性和稳定性的电催化剂对于电化学还原CO2至关重要.在这项研究中,我们使用简单的电沉积方法合成了具有纳米晶枝状结构的CuAu合金电极.各项表征显示原子比约为1∶1的CuA... 相似文献
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本文通过控制电位还原氧化石墨烯,可控制备不同含氧官能团的石墨烯纳米材料。以多巴胺、[Fe(CN)_6]~(3-)、NADH为电活性探针,研究了石墨烯表面含氧官能团、缺陷、表面荷电性质以及导电性等对石墨烯电催化性能的影响。研究发现,低还原程度的氧化石墨烯表面含有大量缺陷和丰富的官能团,能够促进多巴胺自催化反应,也有利于K_3[Fe(CN)_6]在电极表面的电子转移;随着氧化石墨烯还原程度提高,其导电性逐渐得到改善,且其表面官能团和缺陷位点数量逐渐减少,对NAD~+的吸附变弱,因而能促进NADH发生电催化氧化。 相似文献
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二氧化碳(CO2)排放导致了严重的温室效应, 但作为重要的碳资源, CO2电催化还原合成化学品因反应条件温和、 反应产物可调及可有效利用分布式电能等优势而备受关注. 在该反应体系中, 电解液作为反应介质, 可提供质子和反应微环境, 影响分子/离子传输. 因此, 构建新型电解液体系对于提高CO2电催化还原产物的选择性和电流密度起到重要作用. 本文综合评述了CO2电催化还原过程中电解液的作用和研究现状, 重点总结了水系电解液中阴阳离子(碱金属阳离子、 卤素离子等)和离子液体电解液对CO2溶解度、 界面双电层结构(pH值、 电场效应)和中间体稳定性等的影响机制, 揭示了其调控对反应产物的选择性、 电流密度等的影响规律. 最后, 对电解液调控CO2电催化还原性能的研究进行了展望. 相似文献
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采用低温水热合成法制备了碳纸基底的SnO2气体扩散电极(SnO2/GDE), 并对其物化特性与催化还原CO2产甲酸性能进行了研究. 扫描电子显微镜、 X射线衍射及X射线光电子能谱表征结果表明, 在60, 75, 100 ℃下制备的催化剂均为分散性良好的纳米SnO2粉体, 其粒径分别为7.9, 11.8和12.9 nm. 循环伏安、 线性扫描伏安和电化学交流阻抗测试结果显示电极均具有优异的电催化活性, 其电化学活性表面积分别为150, 470, 240 cm 2, 通过等效电路拟合后电阻分别为8.5, 3.9, 6.6 Ω·cm 2. 在-1.8 V(vs. SCE)电位下电解, 通入电量500 C时, 电极都具有较高电催化还原CO2产甲酸性能, 而75 ℃下制备的电极性能最佳, 产甲酸电流密度为22.8 mA/cm 2 , 产甲酸法拉第效率高达93.5%; 该电极经过20 h长时间电解后, 产甲酸电流密度可维持在12.8 mA/cm 2 , 产甲酸法拉第效率稳定在约65%. 相似文献
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It has been shown it is possible to reduce carbon dioxide electrochemically using benzil as a homogeneous electron transfer
agent. It was found that oxalic acid is the basic product formed during the electrochemical reduction of carbon dioxide.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 1, pp. 29–32, January–February, 2006. 相似文献
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Qingyun Gu Zhenfeng Cheng Dr. Xiaodong Qiu Dr. Xiaobao Zeng 《Chemical record (New York, N.Y.)》2023,23(1):e202200177
Isocyanides are well-known as efficient CO surrogates and C1 synthons in modern organic synthesis. Although tremendous efforts have been devoted to fully exploiting the reactivity of isocyanides, these transformations are primarily limited by their utilization of stoichiometric toxic chemical oxidants. With the recent resurgence of organic electrochemistry, which has considerably laid dormant over the past several decades, electrolysis has been identified as a green and powerful tool to enrich structural diversity by solely utilizing electric current as clean and inherently safe redox equivalents of stoichiometric chemical oxidants. In this regard, the unique reactivity of isocyanides has been studied in numerous electrochemical transformations. This review comprehensively highlights the most relevant progress in electrochemical strategies towards the functionalization of isocyanides up until June of 2022, with a focus on reaction outcomes and mechanisms. 相似文献
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氢气是一种清洁、高效、可再生的新型能源,并且是未来碳中和能源供应中最具潜力的化石燃料替代品。因此,可持续氢能源制造具有极大的吸引力与迫切的需求,尤其是通过清洁、环保、零排放的电解水方法。然而,目前的电解水反应受到其缓慢的动力学以及低成本/能源效率的制约。在这些方面,电化学合成通过制造先进的电催化剂和提供更高效/增值的共电解替代品,为提高水电解的效率和效益提供了广阔的前景。它是一种环保、简单的通过电解或其他电化学操作,对从分子到纳米尺度的材料进行制造的方法。本文首先介绍了电化学合成的基本概念、设计方法以及常用方法。然后,总结了电化学合成技术在电解水领域的应用及进展。我们专注于电化学合成的纳米结构电催化剂以实现更高效的电解水制氢,以及小分子的电化学氧化以取代电解水制氢中的析氧共反应,实现更高效、 增值的共电解制氢。我们系统地讨论了电化学合成条件与产物的关系,以启发未来的探索。最后,本文讨论了电化学合成在先进电解水以及其他能量转换和储存应用方面的挑战和前景。 相似文献
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Tanyuan Wang Dongliang Gao Junqiao Zhuo Prof. Zhiwei Zhu Prof. Pagona Papakonstantinou Prof. Yan Li Prof. Meixian Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(36):11939-11948
MoS2 particles with different size distributions were prepared by simple ultrasonication of bulk MoS2 followed by gradient centrifugation. Relative to the inert microscale MoS2, nanoscale MoS2 showed significantly improved catalytic activity toward the oxygen‐reduction reaction (ORR) and hydrogen‐evolution reaction (HER). The decrease in particle size was accompanied by an increase in catalytic activity. Particles with a size of around 2 nm exhibited the best dual ORR and HER performance with a four‐electron ORR process and an HER onset potential of ?0.16 V versus the standard hydrogen electrode (SHE). This is the first investigation on the size‐dependent effect of the ORR activity of MoS2, and a four‐electron transfer route was found. The exposed abundant Mo edges of the MoS2 nanoparticles were proven to be responsible for the high ORR catalytic activity, whereas the origin of the improved HER activity of the nanoparticles was attributed to the plentiful exposed S edges. This newly discovered process provides a simple protocol to produce inexpensive highly active MoS2 catalysts that could easily be scaled up. Hence, it opens up possibilities for wide applications of MoS2 nanoparticles in the fields of energy conversion and storage. 相似文献
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T. V. Magdesieva A. V. Dolganov A. V. Yakimanskii M. Ya. Goikhman I. V. Podeshvo V. V. Kudryavtsev 《Russian Journal of Electrochemistry》2007,43(10):1133-1143
Method of electrochemical synthesis of new Cu-containing polyheteroarylenes that have biquinolyl units in their main chain is developed on the base of the soluble anode technique. The study of electrochemical properties of thus obtained Cu-containing polymer and the corresponding monomer complex revealed existence of two types of coordination environment: (1) copper Cu(I) in the tetrahedral surrounding of two biquinolyl ligands and (2) copper Cu(I) bound with only one biquinolyl fragment. The complexes with one biquinolyl polymer ligand showed high activity as catalysts for O2 reduction in the presence of hydroquinone that is converted to quinone in the course of the reaction. 相似文献
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Perfluorinated Covalent Triazine Framework Derived Hybrids for the Highly Selective Electroconversion of Carbon Dioxide into Methane 下载免费PDF全文
Yuanshuang Wang Junxiang Chen Genxiang Wang Yan Li Prof. Dr. Zhenhai Wen 《Angewandte Chemie (International ed. in English)》2018,57(40):13120-13124
Developing cost‐effective electrocatalysts for high‐selectivity CO2 electroreduction remains challenging. We herein report a perfluorinated covalent triazine framework (CTF) electrocatalyst that displays very high selectivity in the electroreduction of CO2 to CH4 with a faradaic efficiency of 99.3 % in aqueous electrolyte. Systematic characterization and electrochemical studies, in combination with density functional theory calculations, demonstrate that the presence of both nitrogen and fluorine in the CTF provides a unique pathway that is inaccessible with the individual components for CO2 electroreduction. 相似文献
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IntroductionPolyoxometalates (POMs)arealargeandrapidlygrowingclassofcompoundsthatgenerallyundergoaseriesofconsecutiveone ormulti electronreversibleredoxpro cesses.1 4 Thispropertymakesthemveryattractiveinelectrodemodification .SadakaneandSteckhan5havepre se… 相似文献
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High‐Yield Electrosynthesis of Hydrogen Peroxide from Oxygen Reduction by Hierarchically Porous Carbon 下载免费PDF全文
Yanming Liu Prof. Xie Quan Xinfei Fan Dr. Hua Wang Dr. Shuo Chen 《Angewandte Chemie (International ed. in English)》2015,54(23):6837-6841
H2O2 production by electroreduction of O2 is an attractive alternative to the current anthraquinone process, which is highly desirable for chemical industries and environmental remediation. However, it remains a great challenge to develop cost‐effective electrocatalysts for H2O2 synthesis. Here, hierarchically porous carbon (HPC) was proposed for the electrosynthesis of H2O2 from O2 reduction. It exhibited high activity for O2 reduction and good H2O2 selectivity (95.0–70.2 %, most of them >90.0 % at pH 1–4 and >80.0 % at pH 7). High‐yield H2O2 generation has been achieved on HPC with H2O2 concentrations of 222.6–62.0 mmol L?1 (2.5 h) and corresponding H2O2 production rates of 395.7–110.2 mmol h?1 g?1 at pH 1–7 and ?0.5 V. Moreover, HPC was energy‐efficient for H2O2 production with current efficiency of 81.8–70.8 %. The exceptional performance of HPC for electrosynthesis of H2O2 could be attributed to its high content of sp3‐C and defects, large surface area and fast mass transfer. 相似文献