Virginie Lair

Chimie ParisTech · Institut de Recherche de Chimie Paris

Two new acentric oxycarbonates Na6Li4MO4(CO3)4 (M = W and Mo) were synthesized via a conventional solid-state route. Their structure was determined from X-ray diffraction data on single crystals. Na6Li4MO4(CO3)4 (M = W and Mo) crystallizes in the acentric cubic P-43m space group (a ≈ 7.15 Å). It is composed of MLi4O16 units built from MO4 and LiO4...

Two acetate ionic liquids (ILs) based on N-methyl-pyrrolidinium cation with etheric (mPEGn-) and aliphatic (butyl-) substitutions were synthetized. Electrochemical potential windows (EPWs) were measured on a glassy carbon electrode. The results revealed that introduction of etheric group in the IL structure constricts the EPW if compared with aliph...

Due to a high conductivity of about 0.1 S·cm −1 , Li-Na-K carbonate eutectic and Sm-doped ceria composite material is a good electrolyte candidate for hybrid fuel cells operating between 500 °C and 600 °C. The present paper aims at a deeper understanding of the species and mechanisms involved in the ionic transport through impedance spectroscopy an...

The matrix material in a Molten Carbonate Fuel Cell, usually LiAlO2, has an important role in the ionic conduction, gas sealing and electrolyte retention. To avoid cracking, this material has been reinforced with various additives, mostly Al-based, which are subject to in situ lithiation. In this work, matrices were systematically synthesized throu...

Co-electrolysis of water and carbon dioxide in molten carbonates is nowadays a key issue in MCEC (molten carbonate electrolysis cell) and, reversely, for a better understanding of MCFC (molten carbonate fuel cell). The products of water and carbon dioxide reduction are the fuels that might be used in MCFC or other energy devices. The present study...

Due to their low melting point and high conductivity molten hydroxides are interesting electrolytes, or additive to other molten electrolytes for high-temperature electrochemical devices. There is nowadays a revival of such reactive media, first of all for their significant role in the electrode mechanisms in molten carbonate fuel cells (MCFCs) and...

CO2 plays a major role in the molten carbonate fuel cell (MCFC) and its reverse process, the molten carbonate electrolysis cell (MCEC), because of the capability of the mentioned electrolyte to capture big amounts of this greenhouse gas. In particular, the co-electrolysis process together with water, would ideally yield syngas (H2 + CO). The reduct...

In order to reduce carbon dioxide emission, one solution is to convert into valuable chemicals or fuels, e.g. transforming CO2 into CO by electrochemical reduction. Thus, this greenhouse gas could be re-used in particular as syngas (CO + H2) by co-electrolysis of CO2/H2O. High temperature electrolysis cells can be the best energetic devices to prod...

As the capture and valorization of CO2 in molten carbonates is nowadays becoming a strategic energy topic, the need of accurate solubility measurements of such molecule is becoming compulsory. This study provides a new set of reliable CO2 solubility values, determined by a a carefully adapted manometric setup, in Li2CO3-K2CO3 (62:38 mol%), Li2CO3-N...

In this study, the electrochemical breakdown potentials (Eb) of NiTi stents were assessed in correlation to their nonmetallic inclusion fractions in the extra low inclusion (ELI) range (inclu.% < 1% in area fraction, average size <39 μm). Quantitative investigations were performed to study the role of nonmetallic inclusions during pitting corrosion...

In this work, PdFe2O3 bimetallic materials containing oxygen vacancies (Ov, from 10 to 75%) and two bimetallic nanoparticles based on noble metals (PdAu and PdPt) were obtained and evaluated for the ethanol electro‒oxidation reaction (EOR) in alkaline medium. For this purpose, bimetallic nanoparticles were synthesized keeping similar crystallite si...

A three-electrode electrochemical cell was used for the synthesis of ceria thin films in an aqueous nitrate media, using the electrogenerated base method. The choice of the precursor of hydroxide is important regarding the mechanisms involved and the morphology of the deposits. The current-time curves were analyzed for the estimation of the growth...

Sorbitol is a potentially cheap fuel that can be easily produced from biomass. However, despite its renewable character, the sorbitol electro-oxidation reaction (SOR) has been barely studied, being mostly analyzed using massive or nanoparticulate Pt-based materials, exhibiting poor activity. This work proposes the green synthesis of Au/C, Pd/C and...

This paper is dedicated to the impact of pressure on the electrochemical behaviour of LSCF (La1-xSrxCoyFe1-yO3-δ) anode in high-temperature electrolysers. This study was carried out with symmetrical cells associating LSCF electrodes to a 3YSZ (yttrium-stabilised zirconia) electrolyte. Impedance spectroscopy measurements were performed using a three...

Small fiber peripheral neuropathy is an early complication of diabetes. Electric skin response to some stimulus, as electrochemical skin conductance ECS, is a promising route in the early follow‐up of such diseases. It is related to sweat gland innervations and their permeability to chlorides and protons; it is non‐invasive, quantitative and reprod...

This is an overview of the electrochemical characterization of nickel and stainless steel (so‐called SS) as electrodes in medical devices for the early diagnosis of small fiber neuropathy that originates from type‐2 diabetes or cystic fibrosis. The electrical current responses obtained during the clinical tests are related to the amount of chloride...

Adsorption of self-assembled monolayer (SAM) of different imidazolines derivatives was investigated on Fe2O3 (0 0 0 1) surface with DFT calculations to understand their corrosion inhibition mechanism. Quantum chemistry calculations enable us acquiring a better insight on the nature of imidazoline/surface interactions, i.e. partly covalent bonds, an...

AISI 304L is used in SudoscanTM technology (Impeto Medical Inc.) for the early diagnosis of small fiber neuropathy caused by type-2 diabetes or cystic fibrosis. In a recent paper, several substitute electrodes were analyzed, among which the biocompatible nickel-free AISI 430 appeared as an interesting material. In the present work, we compare in de...

Room temperature ionic liquids (RTILs) attract much attention as a new type of environmentally benign electrolytes for Li-ion batteries due to their numerous interesting physicochemical properties. Here, in this paper, Li intercalation/deintercalation in presence of the N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR14TFSI) a...

Carbon capture and valorization is a new route increasingly discussed to reduce greenhouse gas emissions. One of the paths foreseen for CO2 valorization is its transformation into fuels by electrochemical reduction of carbon dioxide. In this approach, molten carbonates are of particular interest since they can be used to capture CO2 molecule becaus...

This chapter is dedicated to the unique fuel cell using a molten salt electrolyte, the molten carbonate fuel cell (MCFC). This generator device operating at 650 °C has produced more power in the last 3 years (250 MW) than any other fuel cell. Our aim is to describe briefly the principles, including a focus on electrode reactions, and configuration...

Improvement of the molten carbonate fuel cell electrolyte is a key parameter to increase the performance of such electrochemical generator. One of the main challenges is to enhance the global oxygen reduction at the state-of-the-art porous nickel cathode. In this study, the effect of adding 5 mol% of caesium in Li[single bond]K and Li[single bond]N...

The electrochemical transformation of CO2 into more valuable chemicals such as CO offers great interest in the energetic field. In this paper, the feasibility of this valorisation process is investigated by cyclic voltammetry in different binary molten carbonates: Li2CO3 Na2CO3 (52:48 mol. %), Li2CO3 K2CO3 (62:38 mol. %) and Na2CO3 K2CO3 (56:44 mol...

This study addresses the problem of the nickel cathode dissolution, decreasing the lifetime of molten carbonate fuel cells, by a protective coating of Nb2O5 processed by atomic layer deposition ALD onto the porous cathode substrate. Samples of different thicknesses were tested electrochemically in molten Li2CO3-K2CO3 eutectic at 650 °C during 230 h...

The capture and utilization of CO2 is becoming progressively one of the significant challenges in the field of energetic resources. Whatever the energetic device, it is impossible to avoid completely the production of greenhouse gas, even parting from renewable energies. Transforming CO2 into a valuable fuel, such as alcohols, CO, or even C, could...

Optimization of the molten carbonate electrolyte is the most challenging topic in order to increase the lifetime and performance of the molten carbonate fuel cell (MCFC). Besides controlling electrolyte properties such as stability, conductivity, volatility, surface tension, molar volumes etc., it is mandatory to reduce the dissolution of the LixNi...

A non-invasive device based on measurements of electrochemical skin conductance can detect small fiber neuropathy, a sweat gland dysfunction implicated in several diseases. The measurement is related to sweat composition and notably to chloride concentration. To optimize the electrode material, in vitro experiments are performed in mimetic sweat so...

In order to improve the industrial attractiveness of high temperature steam electrolysis (HTSE), increasing the operating pressure is one of the most promising solutions. In this context, this study is dedicated to the analysis of the pressure influence on the electrochemical reactions occurring in HTSE. The behavior of half-cells constituted by YS...

The opportunistic fungal pathogen Aspergillus fumigatus is increasingly found as a coinfecting agent along with Pseudomonas aeruginosa in cystic fibrosis patients. Amongst the numerous molecules secreted by P. aeruginosa during its growth, phenazines constitute a major class. P. aeruginosa usually secreted four phenazines, pyocyanin (PYO), phenazin...

Supplemental data revised

During the past decade, the number of terrorism acts has increased and the need for efficient explosive detectors has become an urgent worldwide necessity. A prototype, Nebulex™, was recently developed in our laboratory. Basically, it couples the solubilization of an analyte from the atmosphere by a nebulization process and in-situ detection. This...

This work is dedicated to the feasibility of CO2 dissolution and transformation into CO by an electroreduction process. It is first based on a predictive thermodynamic study, through the establishment of potential-oxoacidity diagrams, mainly focused on competing reduction processes (CO2/CO, CO2/C, H2O/H2, M+/M) relative to pure Li, Na and K carbona...

Cerium oxide based materials are versatile compounds in terms of properties and applications. This work analyses the production of thin layers, of less than 2 μm thick of Gd-doped ceria (GDC) solid solution for high temperature electrochemical applications such as fuel cells and electrolyser cells. We focused on the synthesis of the deposit by cath...

This chapter is dedicated to some significant applications of membranes in the field of energy, focusing on fuel cells and electrolytic cells. Both electrochemical devices are part of an international effort at both fundamental and demonstration levels and, in some specific cases, market entry has already begun. Membranes can be considered as separ...

One of the main issues for optimizing the molten carbonate fuel cell (MCFC) is the control of the corrosion and dissolution of the state-of-the-art porous nickel oxide cathode. A protective coating constituted by more stable oxides seems to be the best solution. In this paper, very thin layers of TiO2 (50 and 300 nm) are processed by a sequential C...

Chemical and electrochemical reactions in molten carbonates offer a large extent of uses, in particular, in the field of energy production. Such media involve species, such as carbon and carbonaceous species (carbon dioxide or monoxide), significant for energy generation or even for the production of fuels. Moreover, their oxidative character due t...

During the past ten years, the use of artisanal explosive compositions in terrorism attacks has increased and efficient detectors are greatly needed. Nitromethane is an interesting target for detection due to its uses in artisanal explosive compositions and also for its carcinogenic characteristics. Several techniques including electrochemistry hav...

This work is dedicated to the feasibility of CO2 dissolution and electroreduction into CO. It is based on a predictive thermodynamic study, through a potential-oxoacidity diagram relative to Li2CO3-K2CO3 (62-38 mol%) eutectic. An experimental analysis by cyclic voltammetry at a gold electrode in the same electrolyte at 575°C shows CO2 reduction wav...

The control of the physicochemical properties of the molten carbonate electrolyte is a key issue for optimising the performance and lifetime of the Molten Carbonate Fuel Cell (MCFC). In particular, the LixNi1−xO cathode dissolution should be kept low by increasing the oxobasicity of the electrolyte, which can be done by adding small amounts of alka...

Nanostructured undoped and samarium doped ceria thin nanocolumnar films are electrodeposited onto (FTO) glass substrates at low-temperature (30 °C) with a subsequent thermal annealing at 600 °C for 1 h. Films are obtained from mixed Sm3+/Ce3+ aqueous nitrate solutions, applying a −0.8 V/(SCE) potential for 1 h. Cubic fluorite type ceria nanostructu...

An electrochemical sensor detects the risk of diabetes and prediabetes; low potentials are applied to nickel electrodes and electrical responses are measured. Although the contact of nickel with skin is short, the risk of allergical reactions cannot be discarded. SS 304L, with lower Ni content, was tested in carbonate buffer solutions containing ch...

Sudomotor dysfunction is a major clinical manifestation of diabetic autonomic neuropathy and is an early sign of prediabetes. SUDOSCAN™, a noninvasive and quick method was developed to assess sudomotor function based on measurement of the electrical current response of the skin when different rectangular pulses of low voltage amplitudes are applied...

We have studied the electrochemical kinetics of anodic Ni dissolution as a function of chloride ion concentration, at pH 5, 6 and 7, in order to mimic the conditions of sweat samples. Our results show that the rate-determining step for Ni dissolution in the mentioned pH range is the transfer of one first electron, as suggested by the Tafel slopes c...

The paper presents two cerium doped lutetium silicate crystals: pyrosilicate Ce:Lu2Si2O7 (LPS) and Ce: Lu2(1-x)Y2xSiO5 (LYSO). These two crystals exhibit the expected requirements for gamma detection: high density and high atomic number, high scintillation light yield, good energy resolution and fast response. LPS and LYSO crystals doped with ceriu...

Electrochemical synthesis of ceria films was performed on a stainless steel substrate in view of Solid Oxide Fuel Cells (SOFC) applications. Films were obtained from aqueous nitrate solutions via cathodic deposition method at room temperature. A constant potential value of −0.8 V/(SCE) was applied to reduce the molecular oxygen as hydroxide precurs...

A medical device called "SUDOSCAN" for diagnosis of sudomotor dysfunctions and detection of diabetes in an early stage uses a set-up of couples of nickel anode and cathode placed on skin region with high density of sweat glands to assess the deviation in sweat ionic balance notably the deviation in chloride concentration. In this paper, it is shown...

Electrical, optical or catalytic properties of ceria can be tuned via doping by rare earth elements. The innate properties of ceria-based materials can be further amplified by using nanostructured ceria. In this study, Sm-doped ceria (SDC) coatings were grown on the FTO glass substrate by means of cathodic deposition. Films were obtained from mixed...

Thin ceria layer deposited by electro-precipitation onto graphite was synthesised and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electro-precipitated ceria has a cubic structure with nanocrystallites of about 6 nm. The SEM analyses shows that the ceria layer reflects...

Samaria (Sm2O3) and samaria-doped ceria (SDC) films are electrochemically deposited on stainless steel in view of a potential use in solid oxide fuel cells. As it is possible to deposit separately pure ceria (CeO2) and pure samaria (Sm2O3) in similar conditions, SDC films were successfully obtained in one electrochemical conditions set. Thin films...

Samarium (Sm)-doped ceria (CeO2) (SDC) is a promising material for high temperature electrochemical devices. Our work demonstrates that thin SDC films can be prepared by a cost-effective electrodeposition method at a low-temperature (30°C) and −0.8V/SCE (saturated calomel electrode) potential. Analysis of the structural properties of the obtained S...

A cerium oxide thin layer was electrodeposited onto stainless steel, using mixed room temperature ionic liquid (the 1-methyl-3-butylimidazolium bis(trifluoromethyl sulfonyl)imide)/ethanol solutions, as electrolytic medium. The hydrophobic ionic liquid content is one of the main parameters in the morphology control influencing the ceria growth rate...

In view of optimizing a multi-electrode device using proprietary technology for noninvasive assessment of eccrine sweat gland activity and thus the early detection of diabetes, we thoroughly explored the electrochemical behavior of a nickel electrode in a three-electrode set up combining a nickel counter electrode and a nickel pseudo-reference elec...

Nanorods, nanocolumnar-based ceria thin films were electrodeposited onto (FTO) or (ITO) glass substrates, at room temperature. Cubic fluorite type ceria nanostructured films of high crystal quality were synthesized on both substrates, as confirmed by X-ray diffraction and Raman spectroscopy. It was found that a substrate is a structure-directing ag...

Ionic Liquids (IL) are novel materials with a wide range of applications. The variable combination of organic cation and inorganic anion offers the possibility of tuning their properties. In the present investigation we test the application of different ionic liquids as charging agents for the preparation of stable oxide suspensions for direct use...

A rapid overview is given on the recent advances of MCFC technology and other fuel cell concepts involving molten carbonates. In order to optimize these processes, new molten carbonate compositions are investigated focusing here on their conductivity, combining thermodynamic predictions and electrochemical measurements.

Ceria-based materials have been synthesized by electrochemical process. Electrodeposition is an interesting cheap method which can be performed at ambient pressure and rather low temperature (less than 100 °C). Moreover, it is easy to control in situ the film thickness. Ceria coatings were obtained by an indirect electrodeposition method. A potenti...

Molten carbonate fuel cell (MCFC) is one of the most advanced high-temperature devices to convert chemical energy into electrical energy without pollution. It can be used in cogeneration as electrical and thermal generator because of its high working temperature (650 °C). Nevertheless, its commercialization is still limited. In fact, its lifetime i...

A synthetic screening is given on interesting materials, dopants and protective coatings allowing a better control of the corrosion in MCFC systems and the optimization of their lifetime. After outlining the interest of MCFC systems with respect to other fuel cell devices, an analysis of the recent literature is given on electrolyte, cathode, anode...

Cerium-based oxides usually find application as electrolyte for SOFC applications, but can also be considered as potential protective coating of interconnect materials. Films of ceria were obtained on stainless steel via a cathodic electrolytic deposition method, at elevated temperature. The submicronic films were characterized using X-ray diffract...

Low DC active current through Nickel electrodes applied on skin in places like hands, forehead and feet provides a novel non invasive diagnostic tool using reverse iontophoresis. This work describes the electrochemistry reactions involved and some medical applications, such as diagnostics of neuropathy, diabetes and cardiac diseases. Finally we pro...

Ferric product powders were synthesised. The purity of each compound was controlled by FTIR and XRD analysis; the BET surface area and electrical conductivity were also reported. The galvanostatic electrochemical reduction of graphite/ferric product composite electrodes was investigated at 25 °C in mildly alkaline pH-buffered solutions containing c...

To evaluate the role of hydrophobic and electrostatic or other polar interactions for protein-ligand binding, we studied the interaction of human serum albumin (HSA) and beta-lactoglobulin with various aliphatic (C10-C14) cationic and zwitterionic detergents. We find that cationic detergents, at levels that do not cause unfolding, interact with a s...

Dodecyldimethylamine N-oxide (DDAO) is a zwitterionic surfactant with acid-base properties. The proton dissociation constant of this surfactant was determined by a novel potentiometric method at "controlled chemical potential" of the proton using a classical pH-glass electrode. When the DDAO was in its monomeric form, the pKa was about 5, consisten...

The formation and structure of corrosion layers on iron are often very complex because a variety of corrosion products can be formed, depending on the history of the samples (type of corrosion, soluble species present in the corrosive medium, temperature, ...). Understanding the transformation pathways that occur during the growth and evolution of...

Adsorption isotherms were determined for dimethyldodecylamine-N-oxide (DDAO) onto Laponite dispersed in water. The isotherms were obtained at pH 3.5 and 4.5 and at various NaCl concentrations (0.1, 0.2, and 0.3 M) by potentiometry, using an electrode sensitive to the nonionic surfactant. The stability of the synthetic clay at the pH values and for...

Adsorption isotherms of dimethyldodecylamine-N-oxide (DDAO) onto laponite were determined by potentiometry, using a surfactant-specific electrode. The isotherms were obtained at pH 7; 8 and 9, and at various NaCl concentrations. The stability of laponite in these conditions was evidenced. All isotherms are mingled in these conditions and the level...