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Corrigendum: Induction of a Proton Gradient across a Gold‐Supported Biomimetic Membrane by Electroenzymatic H2 Oxidation 下载免费PDF全文
Óscar Gutiérrez‐Sanz Cristina Tapia Marta C. Marques Sonia Zacarias Dr. Marisela Vélez Dr. Inês A. C. Pereira Dr. Antonio L. De Lacey 《Angewandte Chemie (International ed. in English)》2015,54(33):9439-9439
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A Reversible Proton Relay Process Mediated by Hydrogen‐Bonding Interactions in [FeFe]Hydrogenase Modeling 下载免费PDF全文
Kai‐Ti Chu Dr. Yu‐Chiao Liu Yi‐Lan Huang Cheng‐Huey Hsu Dr. Gene‐Hsiang Lee Prof. Dr. Ming‐Hsi Chiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):10978-10982
A reversible and temperature‐dependent proton‐relay process is demonstrated for a Fe2 complex possessing a terminal thiolate in the presence of nitrogen‐based acids. The terminal sulfur site (St) of the complex forms a hydrogen‐bond interaction with N,N‐dimethylanilinium acid at 183 K. The Fe2 core, instead, is protonated to generate a bridging hydride at 298 K. Reversibility is observed for the tautomerization between the hydrogen‐bonded pair and the Fe–hydride species. X‐ray structural analysis of the hydrogen‐bonded species at 193 K reveals a short N(H)???St contact. Employment of pyridinium acid also results in similar behavior, with reversible proton–hydride interconversion. DFT investigation of the proton‐transfer pathways indicates that the pKa value of the hydrogen‐bonded species is enhanced by 3.2 pKa units when the temperature is decreased from 298 K to 183 K. 相似文献
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H2 Oxidation Electrocatalysis Enabled by Metal‐to‐Metal Hydrogen Atom Transfer: A Homolytic Approach to a Heterolytic Reaction 下载免费PDF全文
Dr. Geoffrey M. Chambers Dr. Eric S. Wiedner Dr. R. Morris Bullock 《Angewandte Chemie (International ed. in English)》2018,57(41):13523-13527
Oxidation of H2 in a fuel cell converts the chemical energy of the H?H bond into electricity. Electrocatalytic oxidation of H2 by molecular catalysts typically requires one metal to perform multiple chemical steps: bind H2, heterolytically cleave H2, and then undergo two oxidation and two deprotonation steps. The electrocatalytic oxidation of H2 by a cooperative system using Cp*Cr(CO)3H and [Fe(diphosphine)(CO)3]+ has now been invetigated. A key step of the proposed mechanism is a rarely observed metal‐to‐metal hydrogen atom transfer from the Cr?H complex to the Fe, forming an Fe?H complex that is deprotonated and then oxidized electrochemically. This “division of chemical labor” features Cr interacting with H2 to cleave the H?H bond, while Fe interfaces with the electrode. Neither metal is required to heterolytically cleave H2, so this system provides a very unusual example of a homolytic reaction being a key step in a molecular electrocatalytic process. 相似文献
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A Dual‐Phase Ceramic Membrane with Extremely High H2 Permeation Flux Prepared by Autoseparation of a Ceramic Precursor 下载免费PDF全文
Shunfan Cheng Yanjie Wang Libin Zhuang Dr. Jian Xue Dr. Yanying Wei Prof. Armin Feldhoff Prof. Jürgen Caro Prof. Haihui Wang 《Angewandte Chemie (International ed. in English)》2016,55(36):10895-10898
A novel concept for the preparation of multiphase composite ceramics based on demixing of a single ceramic precursor has been developed and used for the synthesis of a dual‐phase H2‐permeable ceramic membrane. The precursor BaCe0.5Fe0.5O3?δ decomposes on calcination at 1370 °C for 10 h into two thermodynamically stable oxides with perovskite structures: the cerium‐rich oxide BaCe0.85Fe0.15O3?δ (BCF8515) and the iron‐rich oxide BaCe0.15Fe0.85O3?δ (BCF1585), 50 mol % each. In the resulting dual‐phase material, the orthorhombic perovskite BCF8515 acts as the main proton conductor and the cubic perovskite BCF1585 as the main electron conductor. The dual‐phase membrane shows an extremely high H2 permeation flux of 0.76 mL min?1 cm?2 at 950 °C with 1.0 mm thickness. This auto‐demixing concept should be applicable to the synthesis of other ionic‐electronic conducting ceramics. 相似文献
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Photoelectrochemical H2 Evolution with a Hydrogenase Immobilized on a TiO2‐Protected Silicon Electrode 下载免费PDF全文
Dr. Chong‐Yong Lee Dr. Hyun S. Park Dr. Juan C. Fontecilla‐Camps Dr. Erwin Reisner 《Angewandte Chemie (International ed. in English)》2016,55(20):5971-5974
The combination of enzymes with semiconductors enables the photoelectrochemical characterization of electron‐transfer processes at highly active and well‐defined catalytic sites on a light‐harvesting electrode surface. Herein, we report the integration of a hydrogenase on a TiO2‐coated p‐Si photocathode for the photo‐reduction of protons to H2. The immobilized hydrogenase exhibits activity on Si attributable to a bifunctional TiO2 layer, which protects the Si electrode from oxidation and acts as a biocompatible support layer for the productive adsorption of the enzyme. The p‐Si|TiO2|hydrogenase photocathode displays visible‐light driven production of H2 at an energy‐storing, positive electrochemical potential and an essentially quantitative faradaic efficiency. We have thus established a widely applicable platform to wire redox enzymes in an active configuration on a p‐type semiconductor photocathode through the engineering of the enzyme–materials interface. 相似文献
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Julian Szczesny James A. Birrell Felipe Conzuelo Wolfgang Lubitz Adrian Ruff Wolfgang Schuhmann 《Angewandte Chemie (International ed. in English)》2020,59(38):16506-16510
The incorporation of highly active but also highly sensitive catalysts (e.g. the [FeFe] hydrogenase from Desulfovibrio desulfuricans) in biofuel cells is still one of the major challenges in sustainable energy conversion. We report the fabrication of a dual‐gas diffusion electrode H2/O2 biofuel cell equipped with a [FeFe] hydrogenase/redox polymer‐based high‐current‐density H2‐oxidation bioanode. The bioanodes show benchmark current densities of around 14 mA cm?2 and the corresponding fuel cell tests exhibit a benchmark for a hydrogenase/redox polymer‐based biofuel cell with outstanding power densities of 5.4 mW cm?2 at 0.7 V cell voltage. Furthermore, the highly sensitive [FeFe] hydrogenase is protected against oxygen damage by the redox polymer and can function under 5 % O2. 相似文献
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Inside Back Cover: A Reversible Proton Relay Process Mediated by Hydrogen‐Bonding Interactions in [FeFe]Hydrogenase Modeling (Chem. Eur. J. 31/2015) 下载免费PDF全文
Kai‐Ti Chu Dr. Yu‐Chiao Liu Yi‐Lan Huang Cheng‐Huey Hsu Dr. Gene‐Hsiang Lee Prof. Dr. Ming‐Hsi Chiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11255-11255
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Raheleh Partovi‐Nia Bin Su Dr. Fei Li Dr. Claude P. Gros Dr. Jean‐Michel Barbe Dr. Zdenek Samec Prof. Hubert H. Girault Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(10):2335-2340
Oxygen reduction : A polarized water|1,2‐dichloroethane (DCE) interface acts as a proton pump for the [Co(tpp)] (TPP=5,10,15,20‐tetraphenylporphyrinato) catalyzed O2 reduction by ferrocene (Fc) compounds to produce H2O2 (see figure; IT=ion transfer, ET=electron transfer). This system favours the collection of H2O2 by extraction immediately after its formation in DCE to the adjacent water phase.
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《化学:亚洲杂志》2017,12(20):2666-2669
Water splitting mediated by electron‐coupled‐proton buffer (ECPB) provides an efficient way to avoid gas mixing by separating oxygen evolution from hydrogen evolution in space and time. Though electrochemical and photoelectrochemcial water oxidation have been incorporated in such a two‐step water splitting system, alternative ways to reduce the cost and energy input for decoupling two half‐reactions are desired. Herein, we show the feasibility of photocatalytic oxygen evolution in a powder system with BiVO4 as a photocatalyst and polyoxometalate H3PMo12O40 as an electron and proton acceptor. The resulting reaction mixture was allowed to be directly used for the subsequent hydrogen evolution with the reduced H3PMo12O40 as electron and proton donors. Our system exhibits excellent stability in repeated oxygen and hydrogen evolution, which brings considerable convenience to decoupled water splitting. 相似文献
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N−H‐Type Excited‐State Proton Transfer in Compounds Possessing a Seven‐Membered‐Ring Intramolecular Hydrogen Bond 下载免费PDF全文
Yi‐An Chen Fan‐Yi Meng Yen‐Hao Hsu Cheng‐Hsien Hung Chi‐Lin Chen Kun‐You Chung Wei‐Feng Tang Prof. Dr. Wen‐Yi Hung Prof. Dr. Pi‐Tai Chou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14688-14695
A series of compounds containing 5‐(2‐aminobenzylidene)‐2,3‐dimethyl‐3,5‐dihydro‐4H‐imidazol‐4‐one ( o ‐ABDI ) as the core chromophore with a seven‐membered‐ring N?H‐type intramolecular hydrogen bond have been synthesized and characterized. The acidity of the N?H proton and thus the hydrogen‐bond strength can be fine‐tuned by replacing one of the amino hydrogen atoms by a substituent R, the acidity increasing with increasing electron‐withdrawing strength of R, that is, in the order H<COCH3<COPh<Tosyl<COCF3. The tosyl and trifluoroacetyl derivatives undergo ultrafast, irreversible excited‐state intramolecular proton transfer (ESIPT) that results in proton‐transfer emission solely in the red region. Reversible ESIPT, and hence dual emission, involving the normal and proton‐transfer tautomers was resolved for the acetyl‐ and benzyl‐substituted counterparts. For o ‐ABDI , which has the weakest acidity, ESIPT is prohibited due to its highly endergonic reaction. The results clearly demonstrate the harnessing of ESIPT by modifying the proton acidity and hydrogen‐bonding strength in a seven‐membered‐ring intramolecular hydrogen‐bonding system. For all the compounds studied, the emission quantum yields are weak (ca. 10?3) in dichloromethane, but strong in the solid form, ranging from 3.2 to 47.4 %. 相似文献
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Infrared Spectroscopy During Electrocatalytic Turnover Reveals the Ni‐L Active Site State During H2 Oxidation by a NiFe Hydrogenase 下载免费PDF全文
Ricardo Hidalgo Dr. Philip A. Ash Dr. Adam J. Healy Prof. Kylie A. Vincent 《Angewandte Chemie (International ed. in English)》2015,54(24):7110-7113
A novel in situ IR spectroscopic approach is demonstrated for the characterization of hydrogenase during catalytic turnover. E. coli hydrogenase 1 (Hyd‐1) is adsorbed on a high surface‐area carbon electrode and subjected to the same electrochemical control and efficient supply of substrate as in protein film electrochemistry during spectral acquisition. The spectra reveal that the active site state known as Ni‐L, observed in other NiFe hydrogenases only under illumination or at cryogenic temperatures, can be generated reversibly in the dark at ambient temperature under both turnover and non‐turnover conditions. The observation that Ni‐L is present at all potentials during turnover under H2 suggests that the final steps in the catalytic cycle of H2 oxidation by Hyd‐1 involve sequential proton and electron transfer via Ni‐L. A broadly applicable IR spectroscopic technique is presented for addressing electrode‐adsorbed redox enzymes under fast catalytic turnover. 相似文献
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微型氢气/空气自呼吸式质子交换膜燃料电池 总被引:6,自引:0,他引:6
数码相机、手提电脑和移动电话等各种新型的电子产品对电池的能量要求越来越高.例如,配备最新的Li离子电池的数码相机只能连续工作30min,手提电脑只运行3h.显然传统电池的发展已越来越不能满足便携式电子设备的用电需求.微型质子交换膜燃料电池(μPEMFC)由于具有高比能量、无需充电和无自放电等优点,在便携式电子设备中具有广阔的应用前景.然而,用传统技术制作μPEMFC不能适应PEMFC微型化要求.因此基于微机电系统(MEMS)技术的微型质子交换膜燃料电池(μPEMFC)已成为国际上的研究热点.2000年,Kelley等基于MEMS技术制作了μPEMFC,随后又在30℃,用加湿氢气作燃料,压缩空气为氧化剂(流速为0.2L/min),电池峰值功率约为120mW/cm^2等条件下进一步研究了μPEMFC。 相似文献
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《应用有机金属化学》2017,31(11)
The reaction of 2‐ethyl‐2‐(2‐hydroxybenzylideneamino)propane‐1,3‐diol (H3L) with CuCl2⋅2H2O affords a new copper complex, [ClCu(H2L)], which has been determined using X‐ray crystallography. In the solid, copper atom is four‐coordinated by two oxygen atoms and one nitrogen atom from the ligand and one chlorine atom. Electrochemical studies show that the complex can act as an electrocatalyst for hydrogen evolution from a dimethylformamide solution of acetic acid and a neutral buffer (pH = 7.0) with a turnover frequency of 46.2 and 482 moles of hydrogen per mole of catalyst per hour at an overpotential of 941.6 and 837.6 mV, respectively. 相似文献
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Volha Vetokhina Dr. Krzysztof Dobek Michał Kijak Izabela I. Kamińska Keven Muller Prof. Werner R. Thiel Prof. Jacek Waluk Prof. Jerzy Herbich 《Chemphyschem》2012,13(16):3661-3671
Studies of 2‐(1H‐pyrazol‐5‐yl)pyridine (PPP) and its derivatives 2‐(4‐methyl‐1H‐pyrazol‐5‐yl)pyridine (MPP) and 2‐(3‐bromo‐1H‐pyrazol‐5‐yl)pyridine (BPP) by stationary and time‐resolved UV/Vis spectroscopic methods, and quantum chemical computations show that this class of compounds provides a rare example of molecules that exhibit three types of photoreactions: 1) excited‐state intramolecular proton transfer (ESIPT) in the syn form of MPP, 2) excited‐state intermolecular double‐proton transfer (ESDPT) in the dimers of PPP in nonpolar media, as well as 3) solvent‐assisted double‐proton transfer in hydrogen‐bonded 1:1 complexes of PPP and MPP with alcoholic partners. The excited‐state processes are manifested by the appearance of a dual luminescence and a bimodal irreversible kinetic coupling of the two fluorescence bands. Ground‐state syn–anti equilibria are detected and discussed. The fraction of the higher‐energy anti form varies for different derivatives and is strongly dependent on the solvent polarity and hydrogen‐bond donor or acceptor abilities. 相似文献