Electrochemical activity of ruthenium and iridium based catalysts for oxygen evolution reaction

International audiencedecomposition process. The suitable heat treatment of the polymeric precursors allowed to recover metal oxides free from organic carbon, which can be oxidized to carbon dioxide during H2O splitting at elevated potentials. The materials were examined by various physicochemical techniques in order to understand their electrochemical behavior as anodes in a 5 cm(2) single proton exchange membrane water electrolyzer. Although the presence of Ir in the electrocatalyst composition contributes undoubtedly to its stability against ruthenium dissolution and the Faradaic efficiency of the PEM electrolysis cell, its great amount increases the overpotential value. The activity of the home made RuxIr1-xO2 anodes towards the oxygen evolution reaction occurs at ca. 1.5 Vat 25 degrees C

A Facile Synthesis of Size-Controllable IrO2 and RuO2 Nanoparticles for the Oxygen Evolution Reaction

The efficiency of the water electrolysis process is restricted by the sluggish kinetics of the oxygen evolution reaction (OER). Developing efficient catalysts and their synthesis methods is highly desired to improve the kinetics of the OER and therefore the overall efficiency of the water electrolysis. In this report, we present a facile wet-chemical method for synthesizing IrO2 and RuO2 nanoparticles (NPs) for the OER. The nanoparticles were synthesized by reducing metal chlorides in ethylene glycol in the presence of polyvinylpyrrolidone, followed by annealing in air. The particle size was controlled by adjusting the annealing temperature. The activity of IrO2 and RuO2 NPs supported on carbon black was investigated by cyclic voltammetry (CV) in alkaline (0.1 M KOH) electrolyte. As-synthesized IrO2 and RuO2 NPs showed high OER activity. The IrO2 NPs exhibited a specific activity of up to 3.5 (±1.6) μA/cm2oxide at 1.53 V (vs. RHE), while the RuO2 NPs achieved a value of 124.2 (±8) μA/cm2oxide. Moreover, RuO2 NPs showed a mass activity for OER, up to 102.6 (±10.5) A/goxide at 1.53 V (vs. RHE), which represents the highest value reported in the literature to date.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore

How are cell and tissue structure and function influenced by gravity and what are the gravity perception mechanisms?

Progress in mechanobiology allowed us to better understand the important role of mechanical forces in the regulation of biological processes. Space research in the field of life sciences clearly showed that gravity plays a crucial role in biological processes. The space environment offers the unique opportunity to carry out experiments without gravity, helping us not only to understand the effects of gravitational alterations on biological systems but also the mechanisms underlying mechanoperception and cell/tissue response to mechanical and gravitational stresses. Despite the progress made so far, for future space exploration programs it is necessary to increase our knowledge on the mechanotransduction processes as well as on the molecular mechanisms underlying microgravity-induced cell and tissue alterations. This white paper reports the suggestions and recommendations of the SciSpacE Science Community for the elaboration of the section of the European Space Agency roadmap “Biology in Space and Analogue Environments” focusing on “How are cells and tissues influenced by gravity and what are the gravity perception mechanisms?” The knowledge gaps that prevent the Science Community from fully answering this question and the activities proposed to fill them are discussed

How do gravity alterations affect animal and human systems at a cellular/tissue level?

The present white paper concerns the indications and recommendations of the SciSpacE Science Community to make progress in filling the gaps of knowledge that prevent us from answering the question: “How Do Gravity Alterations Affect Animal and Human Systems at a Cellular/Tissue Level?” This is one of the five major scientific issues of the ESA roadmap “Biology in Space and Analogue Environments”. Despite the many studies conducted so far on spaceflight adaptation mechanisms and related pathophysiological alterations observed in astronauts, we are not yet able to elaborate a synthetic integrated model of the many changes occurring at different system and functional levels. Consequently, it is difficult to develop credible models for predicting long-term consequences of human adaptation to the space environment, as well as to implement medical support plans for long-term missions and a strategy for preventing the possible health risks due to prolonged exposure to spaceflight beyond the low Earth orbit (LEO). The research activities suggested by the scientific community have the aim to overcome these problems by striving to connect biological and physiological aspects in a more holistic view of space adaptation effects

Nanodendrites of platinum-group metals for electrocatalytic applications

Developing highly efficient and durable catalysts for future electrochemical and energy applications is one of the main subjects of current studies in renewable energy generation. In the past several years, researchers have developed Pt-based alloy electrocatalyst nanomaterials that exhibit promising electrocatalytic properties for various electrochemical applications. The efficient structural and morphological control of Pt-based alloy materials plays a decisive role in achieving these enhanced electrocatalytic properties. The present review article emphasizes the recent progress and important developments in the synthesis and electrocatalytic applications of Pt-group-based nanodendrite materials. The following review will help the exploration and development of better catalysts for practical applications and aims to elucidate the nanodendrite structure of Pt-group metals