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Artero V.,CNRS Chemistry and Biology of Metals Laboratory | Saveant J.-M.,University Paris Diderot
Energy and Environmental Science | Year: 2014

Molecular electrocatalysts for H2 evolution are usually studied under various conditions (solvent and proton sources) that prevent direct comparison of their performances. We provide here a rational method for such a benchmark based on (i) the recent analysis of the current-potential response for two-electron-two-step mechanisms and (ii) the derivation of catalytic Tafel plots reflecting the interdependency of turnover frequency and overpotential based on the intrinsic properties of the catalyst, independent of contingent factors such as cell characteristics. Such a methodology is exemplified on a series of molecular catalysts among the most efficient in the recent literature. © 2014 the Partner Organisations.

Artero V.,CNRS Chemistry and Biology of Metals Laboratory | Fontecave M.,College de France
Chemical Society Reviews | Year: 2013

Catalysis is a key enabling technology for solar fuel generation. A number of catalytic systems, either molecular/homogeneous or solid/heterogeneous, have been developed during the last few decades for both the reductive and oxidative multi-electron reactions required for fuel production from water or CO 2 as renewable raw materials. While allowing for a fine tuning of the catalytic properties through ligand design, molecular approaches are frequently criticized because of the inherent fragility of the resulting catalysts, when exposed to extreme redox potentials. In a number of cases, it has been clearly established that the true catalytic species is heterogeneous in nature, arising from the transformation of the initial molecular species, which should rather be considered as a pre-catalyst. Whether such a situation is general or not is a matter of debate in the community. In this review, covering water oxidation and reduction catalysts, involving noble and non-noble metal ions, we limit our discussion to the cases in which this issue has been directly and properly addressed as well as those requiring more confirmation. The methodologies proposed for discriminating homogeneous and heterogeneous catalysis are inspired in part by those previously discussed by Finke in the case of homogeneous hydrogenation reaction in organometallic chemistry [J. A. Widegren and R. G. Finke, J. Mol. Catal. A, 2003, 198, 317-341]. © 2013 The Royal Society of Chemistry.

Delangle P.,Stendhal University | Mintz E.,CNRS Chemistry and Biology of Metals Laboratory
Dalton Transactions | Year: 2012

Wilson's disease is an orphan disease due to copper homeostasis dysfunction. Mutations of the ATP7B gene induces an impaired functioning of a Cu-ATPase, impaired Cu detoxification in the liver and copper overload in the body. Indeed, even though copper is an essential element, which is used as cofactor by many enzymes playing vital roles, it becomes toxic when in excess as it promotes cytotoxic reactions leading to oxidative stress. In this perspective, human copper homeostasis is first described in order to explain the mechanisms promoting copper overload in Wilson's disease. We will see that the liver is the main organ for copper distribution and detoxification in the body. Nowadays this disease is treated life-long by systemic chelation therapy, which is not satisfactory in many cases. Therefore the design of more selective and efficient drugs is of great interest. A strategy to design more specific chelators to treat localized copper accumulation in the liver will then be presented. In particular we will show how bioinorganic chemistry may help in the design of such novel chelators by taking inspiration from the biological copper cell transporters. © 2012 The Royal Society of Chemistry.

Tran P.D.,CNRS Chemistry and Biology of Metals Laboratory | Artero V.,CNRS Chemistry and Biology of Metals Laboratory | Fontecave M.,CNRS Chemistry and Biology of Metals Laboratory | Fontecave M.,College de France
Energy and Environmental Science | Year: 2010

Photoelectrocatalytic cells for water splitting should combine one or two photosensitive units with a water oxidation catalyst at the anode and a hydrogen evolution catalyst at the cathode. In this perspective article, we first show how a chemist can take the naturally occurring multi-electron catalysts for these two electro- and photochemical reactions, photosystem II and hydrogenases, as a source of inspiration for the design of original, efficient and robust molecular catalysts. The focus of this article is given to the immobilisation of these natural or bio-inspired catalysts onto conducting surfaces and the design of electrode and photoelectrode materials for hydrogen evolution/uptake and water oxidation. © 2010 The Royal Society of Chemistry.

Artero V.,CNRS Chemistry and Biology of Metals Laboratory | Chavarot-Kerlidou M.,CNRS Chemistry and Biology of Metals Laboratory | Fontecave M.,CNRS Chemistry and Biology of Metals Laboratory | Fontecave M.,College de France
Angewandte Chemie - International Edition | Year: 2011

The future of energy supply depends on innovative breakthroughs regarding the design of cheap, sustainable, and efficient systems for the conversion and storage of renewable energy sources, such as solar energy. The production of hydrogen, a fuel with remarkable properties, through sunlight-driven water splitting appears to be a promising and appealing solution. While the active sites of enzymes involved in the overall water-splitting process in natural systems, namely hydrogenases and photosystem II, use iron, nickel, and manganese ions, cobalt has emerged in the past five years as the most versatile non-noble metal for the development of synthetic H 2- and O 2- evolving catalysts. Such catalysts can be further coupled with photosensitizers to generate photocatalytic systems for light-induced hydrogen evolution from water. It's cobalt's turn: Splitting water with light appears to be a promising solution for the renewable production of a fuel such as hydrogen. Recent developments on cobalt-based catalysts for H 2 or O 2 evolution are discussed, along with how they can be coupled with photosensitizers, to generate light-driven systems, or immobilized onto conducting materials to form electrodes or photoelectrodes for integration in a photoelectrochemical cell. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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