Publications associées à Groupe 6 du tableau périodique

Synthesis, isolation and application of a sila-ketenyl anion

Ynolates or ketenyl anions, [RCCO]-, are negatively charged reactive intermediates, which can be generated in situ and used for divergent chemical transformations. Ynolates can react either at the oxygen or carbon centres or across the C-C triple bond, mak ...

Springernature2023

Theory-guided development of homogeneous catalysts for the reduction of CO2 to formate, formaldehyde, and methanol derivatives

Matthew Wodrich, Anne-Clémence Corminboeuf, Shubhajit Das, Hanna Hinrika Cramer

The stepwise catalytic reduction of carbon dioxide (CO2) to formic acid, formaldehyde, and methanol opens non-fossil pathways to important platform chemicals. The present article aims at identifying molecular control parameters to steer the selectivity to ...

2023

Chiral Diimine Complexes of Earth-Abundant Transition Metals for Asymmetric Catalysis

Elena Braconi

The application of Earth-abundant metals in asymmetric catalysis is key to transition towards a more sustainable chemistry. In particular, expanding the library of redox-active ligands capable of supporting Earth-abundant metals is essential in order to re ...

EPFL2022

A concept for the extraction of the most refractory elements at CERN-ISOLDE as carbonyl complex ions

João Pedro Fernandes Pinto Ramos

We introduce a novel thick-target concept tailored to the extraction of refractory 4d and 5d transition metal radionuclides of molybdenum, technetium, ruthenium and tungsten for radioactive ion beam production. Despite the more than 60-year old history of ...

2022

Crystal Structures of AlCr2 and MoSi2: Same Structure Type vs. Different Bonding Pattern

Philip Johannes Walter Moll

In a joint effort utilizing modified sample preparation, microscopy, X-ray diffraction and micro-fabrication, it became possible to prepare single crystals of the "hidden" phase AlCr2. High-resolution X-ray diffraction analysis is described in detail for t ...

2021

Dosimetry modeling and experimental validation for the PETALE program in the CROCUS reactor

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag, Axel Guy Marie Laureau

The PETALE experimental program in the CROCUS reactor intends to provide integral measurements on reactivity worth and dosimetry measurement to constrain nuclear data relative to stainless steel heavy reflectors. The experimental setup consists in eight su ...

2021

Anchoring single platinum atoms onto nickel nanoparticles affords highly selective catalysts for lignin conversion

Paul Joseph Dyson, Gabor Laurenczy, Zhaofu Fei, Antoine Philippe Van Muyden, Ulf Anders Hagfeldt, Jun Li, Lichen Bai, Linfeng Pan, Lu Chen, Yun Tong

Due to the highly complex polyphenolic structure of lignin, depolymerization without a prior chemical treatment is challenging, and new catalysts are required. Atomically dispersed catalysts are able to maximize the atomic efficiency of noble metals, simul ...

ELSEVIER2021

Spatial and temporal integration of visual features

Oh-Hyeon Choung

Visual processing can be seen as the integration and segmentation of features. Objects are composed of contours, integrated into shapes and segmented from other contours. Information also needs to be integrated to solve the ill-posed problems of vision. Fo ...

EPFL2021

Structural Disorder and Magnetic Order in Atomically Thin Crystals

Michele Pizzochero

This Thesis is mainly devoted to the exploration of the structural disorder and magnetic order in two-dimensional crystals by means of first-principles methodologies. Firstly, we present a comparative study of defect formation in the semiconducting 2H and ...

EPFL2020

Oxygen evolution reaction catalyzed by first-row transition metal oxides: stability and mechanism

Aliki Moysiadou

Water splitting offers the opportunity for storing solar energy and, thus, producing carbon-neutral and renewable solar fuels. The process, known as artificial photosynthesis, is limited by the electrocatalytic conversion of water into molecular oxygen. El ...

EPFL2020

In Situ Biostimulation of Cr(VI) Reduction in a Fast-Flowing Oxic Aquifer

Rizlan Bernier-Latmani, Daniel Scott Alessi

Hexavalent chromium is among the most common and hazardous inorganic contaminants in soils and groundwater. A promising in situ bioremediation approach is the delivery of electron donors to stimulate microbially mediated Cr(VI) reduction, producing relativ ...

AMER CHEMICAL SOC2020

The Periodic Table and Kinetics?

André Merbach, Lothar Helm

Mendeleev in his first publication ordered the chemical elements following an apparent periodicity of properties such as atomic volume and valence. The reactivity of the elements was only studied systematically many years later. To illustrate the systemati ...

2019

Modelling of tungsten erosion and deposition in the divertor of JET-ILW in comparison to experimental findings

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Duccio Testa, Jonathan Graves, Sun Hee Kim, Yves Martin, Daniel Scott Alessi, Julio Rodriguez, Patrick Blanchard, Alberto Hernando de Castro, Alessandro Pau, Cristian Sommariva, Henri Weisen, Richard Pitts, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Federico Nespoli, Yao Zhou, David Pfefferlé, Davide Galassi, Antonio José Pereira de Figueiredo, Jonathan Marc Philippe Faustin, Liang Yao, Dalziel Joseph Wilson, Hamish William Patten, Samuel Lanthaler, Bernhard Sieglin, Otto Asunta

The erosion, transport and deposition of tungsten in the outer divertor of JET-ILW has been studied for an H-Mode discharge with low frequency ELMs. For this specific case with an inter-ELM electron temperature at the strike point of about 20 eV, tungsten ...

Elsevier2019

Design of Separated Element Reflector Experiments in CROCUS: PETALE

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag, Mathieu Hursin, Daniel Jerôme Siefman

The present article describes the preliminary design studies for PETALE (Programme d'Etude en Transmission de l'Acier Lourd et ses Elements), an oncoming experimental program in the CROCUS reactor. Within the framework of the Venus-Eole-Proteus collaborati ...

ASTM INTERNATIONAL2018

Machine learning meets volcano plots: Computational discovery of cross-coupling catalysts

Anne-Clémence Corminboeuf, Benjamin André René Meyer, Anatole von Lilienfeld, Boodsarin Sawatlon

The application of modern machine learning to challenges in atomistic simulation is gaining attraction. We present new machine learning models that can predict the energy of the oxidative addition process between a transition metal complex and a substrate ...

2018

Low-cost industrially available molybdenum boride and carbide as “platinum-like” catalysts for the hydrogen evolution reaction in biphasic liquid systems

Hubert Girault, Xile Hu, Kurt Schenk, Heron Vrubel, Micheal Diarmaid Scanlon, Véronique Amstutz

Rarely reported low-cost molybdenum boride and carbide microparticles, both of which are available in abundant quantities due to their widespread use in industry, adsorb at aqueous acid–1,2-dichloroethane interfaces and efficiently catalyse the hydrogen ev ...

Royal Soc Chemistry2013

Amphoteric defects in GaAs leading to Fermi-level pinning: A hybrid functional study

Alfredo Pasquarello, Davide Colleoni

Formation energies and charge transition levels of amphoteric defects in GaAs giving rise to Fermi-level pinning are calculated with hybrid functionals. The hybrid functional results indicate that previously identified defects involving the bistable nature ...

Elsevier2013

Development and Application of Devices for Online Trace Element Analysis of Thermal Process Gases from Woody Feedstocks

Marco Wellinger

When using natural or waste wood in thermo-chemical conversion processes, the presence of a number of heteroatoms (e.g. sulfur, chlorine, potassium and sodium or heavy metals) may hinder the processes themselves as well as pose a threat to equipment and/or ...

EPFL2012

Pulse plating of Ni-W alloys from model electrolytes

Dieter Landolt

Pulse plating of nickel-tungsten alloys has been studied from two citrate ammonia based model electrolytes containing either an excess of nickel or an excess of tungsten. The alloy composition and current efficiency were determined for pulse periods rangin ...

2008

The chemistry of phosphinoamides and related compounds

Paul Joseph Dyson, Zhaofu Fei

This review commences with a survey of the general synthetic routes leading to aminophosphines containing the P-NH subgroup. Recent examples involving functionalised and chiral aminophosphines are included. The synthesis and structural properties of deprot ...

2005