Homogeneous Electron Transfer Catalysis of the Electrochemical Reduction of Carbon Dioxide. Do Aromatic Anion Radicals React in an Outer-Sphere Manner?

Gennaro, Armando; Isse, Abdirisak Ahmed; Savéant, Jean‐Michel; Severin, a and Maria-Gabriella; Vianello, Alessandro

doi:10.1021/ja960605o

Cited by 112 publications

(107 citation statements)

References 61 publications

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“…For example, CO 2 is known to reduce to oxalate, formate and carbonate on negative electrode at normal conditions and oxalate/formate is easily oxidized back to CO 2 on the positive electrode. 26,27 In fact, it's postulated that CO 2 undergoes reduction more easily than the other components of the electrolyte. 26 The cell with more anode (R = 4.54) material may have generated more CO 2 during formation, which stays in the cell and acts as a shuttle.…”

Section: Loss Of Electrolyte With No Shuttlementioning

confidence: 99%

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Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Deshpande

Pan

et al. 2015

J. Electrochem. Soc.

188

127

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For advancing lithium-ion battery (LIB) technologies, a detailed understanding of battery degradation mechanisms is important. In this article, experimental observations are provided to elucidate the relation between side reactions, mechanical degradation, and capacity loss in LIBs. Graphite/Li(Ni 1/3 Mn 1/3 Co 1/3 )O 2 cells of two very different initial anode/cathode capacity ratios (R, both R > 1) are assembled to investigate the electrochemical behavior. The initial charge capacity of the cathode is observed to be affected by the anode loading, indicating that the electrolyte reactions on the anode affect the electrolyte reactions on the cathode. Additionally, the rate of "marching" of the cathode is found to be affected by the anode loading. These findings attest to the "cross-talk" between the two electrodes. During cycling, the cell with the higher R value display a lower columbic efficiency, yet a lower capacity fade rate as compared to the cell with the smaller R. This supports the notion that columbic efficiency is not a perfect predictor of capacity fade. Capacity loss is attributed to the irreversible production of new solid electrolyte interphase (SEI) facilitated by the mechanical degradation of the SEI. The higher capacity fade in the cell with the lower R is explained with the theory of diffusion-induced stresses (DISs). Lithium-ion batteries (LIBs) are widely used in small, portable, electronic devices due to their high energy density, high voltage, low self-discharge rate, and good cycle performance.1,2 Yet, for automotive propulsion applications, LIBs need improvement in volumetric and gravimetric energy density and with performance over the life of the vehicle. This is one of the major motivations of researchers worldwide focusing on developing cheaper and more durable LIBs for applications such as hybrid vehicles, electric vehicles, and other large-scale energy storage systems. 3Capacity decay during storage and charge-discharge cycling is one of the major challenges that limit the life of LIBs. Instability of the electrolyte at the operating potentials results in side reactions on the electrode surfaces, part of which lead to the formation of solid electrolyte interphases (SEIs). [4][5][6][7] Side reactions may result in lower coulombic efficiency, loss of usable capacity of the cell, and increase of cell impedance. Cell performance degradation due to side reactions is termed as chemical degradation, which is known to be the main cause of lithium loss in well-made LIBs. 5,6,[8][9][10] These side reactions lead to marching of the charge and discharge endpoints.11,12 Such side reactions and their effects on the cell life are relatively less explored.The solid state diffusion of lithium atoms in and out of host electrode particles results in diffusion induced stresses (DISs) and volume changes in electrode particles during charge and discharge. Depending upon the operating conditions these stresses may have various effects on the electrodes such as mechanical fatigue and fracture of the electr...

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Section: Loss Of Electrolyte With No Shuttlementioning

confidence: 99%

“…Among these products, oxalates and formates are easily oxidized back to CO 2 on the positive electrode 26,27 while carbonates do not easily dissolve in the electrolyte solvents at normal operating conditions.…”

Section: Loss Of Electrolyte With No Shuttlementioning

confidence: 99%

Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Deshpande

Pan

et al. 2015

J. Electrochem. Soc.

188

127

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“…13,14 They observed a marked difference in the product distribution between direct electrolysis on Hg and electrolysis catalyzed by radical anions. Various mixtures of CO and oxalate were produced in direct electrolysis.…”

Section: Aromatic Nitriles and Esters As Catalystsmentioning

confidence: 99%

Organic molecules as mediators and catalysts for photocatalytic and electrocatalytic CO₂reduction

2013

Chem. Soc. Rev.

254

169

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Reduction of CO 2 by electrochemical and photoelectrochemical methods to produce carbon-rich fuels is a heavily pursued research theme. Most of the current efforts are focused on the development of transition-metal-based catalysts. In this tutorial review, we present an overview of the development of organic molecules as mediators and catalysts for CO 2 reduction. Four classes of organic molecules are discussed: tetraalkylammonium salts, aromatic esters and nitriles, ionic liquids, and pyridinium derivatives. It is shown that reactions mediated or catalyzed by these organic molecules can be competitive compared to their metal-catalyzed counterparts, both in terms of product selectivity and energy efficiency.

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“…[1][2][3][4][5][6][7][8][9][10] However, the chemical reduction of CO2 to highly reduced products such as methanol (CH3OH) remains a daunting task. The groups of Fujita, [11][12][13] Kubiak, 3,14 Meyer, 15-17 Savéant [18][19][20] and others [21][22][23][24][25][26][27][28][29][30][31][32] have made significant contributions to this field, particularly in the fundamental understanding of using transition-metal complexes to catalyze CO2's transformation. Despite these advances, many challenges remain: for example, CO2 reduction has largely been confined to 2e -products such as CO and formate, and in many cases large overpotentials are required to drive these reactions.…”

Section: Introductionmentioning

confidence: 99%

Reduction of CO₂ to Methanol Catalyzed by a Biomimetic Organo-Hydride Produced from Pyridine

Lim¹,

Holder²,

et al. 2014

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ABSTRACT:We use quantum chemical calculations to elucidate a viable homogeneous mechanism for pyridine-catalyzed reduction of CO2 to methanol. In the first component of the catalytic cycle, pyridine (Py) undergoes a H + transfer (PT) to form pyridinium (PyH + ) followed by an e -transfer (ET) to produce pyridinium radical (PyH 0 ). Examples of systems to effect this ET to populate PyH + 's LUMO (E 0 calc ~ -1.3V vs. SCE) to form the solution phase PyH 0 via highly reducing electrons include the photo-electrochemical p-GaP system (ECBM ~ -1.5V vs. SCE at pH= 5) and the photochemical [Ru(phen)3] 2+ /ascorbate system. We predict that PyH 0 undergoes further PT-ET steps to form the key closed-shell, dearomatized 1,2-dihydropyridine (PyH2) species. Our proposed sequential PT-ET-PT-ET mechanism transforming Py into PyH2 is consistent with the mechanism described in the formation of related dihydropyridines. Because it is driven by its proclivity to regain aromaticity, PyH2 is a potent recyclable organo-hydride donor that mimics the role of NADPH in the formation of C-H bonds in the photosynthetic CO2 reduction process. In particular, in the second component of the catalytic cycle, we predict that the PyH2/Py redox couple is kinetically and thermodynamically competent in catalytically effecting hydride and proton transfers (the latter often mediated by a proton relay chain) to CO2 and its two succeeding intermediates, namely formic acid and formaldehyde, to ultimately form CH3OH. The hydride and proton transfers for the first reduction step, i.e. reduction of CO2, are sequential in nature; by contrast, they are coupled in each of the two subsequent hydride and proton transfers to reduce formic acid and formaldehyde.

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Homogeneous Electron Transfer Catalysis of the Electrochemical Reduction of Carbon Dioxide. Do Aromatic Anion Radicals React in an Outer-Sphere Manner?

Cited by 112 publications

References 61 publications

Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Organic molecules as mediators and catalysts for photocatalytic and electrocatalytic CO₂reduction

Reduction of CO₂ to Methanol Catalyzed by a Biomimetic Organo-Hydride Produced from Pyridine

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Homogeneous Electron Transfer Catalysis of the Electrochemical Reduction of Carbon Dioxide. Do Aromatic Anion Radicals React in an Outer-Sphere Manner?

Cited by 112 publications

References 61 publications

Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Electrode Side Reactions, Capacity Loss and Mechanical Degradation in Lithium-Ion Batteries

Organic molecules as mediators and catalysts for photocatalytic and electrocatalytic CO2reduction

Reduction of CO2 to Methanol Catalyzed by a Biomimetic Organo-Hydride Produced from Pyridine

Contact Info

Product

Resources

About

Organic molecules as mediators and catalysts for photocatalytic and electrocatalytic CO₂reduction

Reduction of CO₂ to Methanol Catalyzed by a Biomimetic Organo-Hydride Produced from Pyridine