Publications associées à Shape-Dependence of Pd Nanocrystal Carburization during Acetylene Hydrogenation

Novel Alkynylation Methods through the Combination of Hypervalent Iodine Reagents and Alkynyl-trifluoroborate Salts

The alkyne motif is a versatile functional group often encountered in organic chemistry. It can be involved in various transformations such as the alkyne-azide cycloaddition and has found widespread application in medicinal chemistry, chemical biology and ...

EPFL2024

Murunskite - a new class of functional material

Davor Tolj

The subject of the present work is discovery and in-depth characterization of a new class of functional materials. Tuning of the bond polarity and orbital occupation with a goal of establishing balance between localization and delocalization of electrons - ...

EPFL2023

Processing and micro-mechanical characterization of multi-component transition MC carbides in iron

Andreas Mortensen, Léa Deillon, Lionel Michelet, Goran Zagar, Marta Fornabaio

We prepare multi-component transition monocarbides of chosen composition by arc-melting together a pre-alloy of the transition metals and cast iron. Based on the elements Ti, Ta, V, Nb and W, 51 different binary, ternary and quaternary compositions are pro ...

2021

Mechanisms of the Heterogeneously Catalyzed Reaction of CO2 Hydrogenation on Transition Metal Surfaces

Kun Zhao

Renewable energy supply and energy storage in a closed materials cycle are the urgent global challenges of the 21st century. Carbon dioxide (CO2) hydrogenation over catalysts is a method to produce synthetic fuels from renewable energy in a CO2 neutral cyc ...

EPFL2020

Ab-initio calculation of surface phonons at the Sb2Te3(111) surface

Davide Campi

Density functional perturbation theory is used to study the phonon dispersion relations at the (111) surface of the topological insulator Sb2Te3. Inelastic Helium atom scattering experiments at the (111) surface of the similar Bi2Se3 topological insulator ...

ELSEVIER SCIENCE BV2018

CO2 hydrogenation reaction over pristine Fe, Co, Ni, Cu and Al2O3 supported Ru: Comparison and determination of the activation energies

Andreas Züttel, Robin Tobias Andreas Mutschler, Wen Luo, Noris André Gallandat, Emanuele Moioli

Fe, Co, Ni and Cu are the main non-noble industrially significant catalysts in the CO2 and CO gas phase hydrogenation reaction towards hydrocarbons and alcohols. These catalysts are typically supported on metal oxides such as SiO2, TiO2, Al2O3 and ZnO, in ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2018

Acetylene Oligomerization over Pd Nanoparticles with Controlled Shape: A Parahydrogen-Induced Polarization Study

Lioubov Kiwi, Rocio Micaela Crespo Quesada

Substantial signal enhancements achieved by using parahydrogen in catalytic hydrogenations are powerful tools for mechanistic studies of chemical reactions involving molecular H-2. Potentially, this technique can be extended to other reaction classes, prov ...

American Chemical Society2016

On-Surface Assembly and Reactions of Organic Molecules in Ultra-High Vacuum

Claudius Morchutt

This thesis comprises the study of two types of 2D materials, those stabilized by non-covalent and those by covalent interactions. They are synthesized and studied on well-defined metallic surfaces in ultra-high vacuum (UHV). The self-assembly of terephtha ...

EPFL2016

Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds with Hypervalent Iodine Reagents

Jérôme Waser, Durga Prasada Rao Hari

Alkynes have found widespread applications in synthetic chemistry, biology, and materials sciences. In recent years, methods based on electrophilic alkynylation with hypervalent iodine reagents have made acetylene synthesis more flexible and efficient, but ...

American Chemical Society2016

Size and Shape-controlled Pd Nanocrystals on ZnO and SiO2: When the Nature of the Support Determines the Active Phase

Lioubov Kiwi, Rocio Micaela Crespo Quesada

The structure sensitivity of acetylene hydrogenation was studied over size-controlled cubic and octahedral Pd nanocrystals (NCs) supported on ZnO and SiO2. Acetylene hydrogenation was found to be structure sensitive [with Pd(111) in octahedra being more ac ...

Wiley-VCH Verlag2014

Pd(0)-Catalyzed Alkene Oxy- and Aminoalkynylation with Aliphatic Bromoacetylenes

Raha Sedigh-Zadeh, Jérôme Waser, Stefano Nicolai

Tetrahydrofurans and pyrrolidines are among the most important heterocycles found in bioactive compounds. Cyclization-functionalization domino reactions of alcohols or amines onto olefins,constitute one of the most efficient methods to access them. In this ...

American Chemical Society2013

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

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

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

Structure sensitivity of selective acetylene hydrogenation over the catalysts with shape-controlled palladium nanoparticles

Lioubov Kiwi, Rocio Micaela Crespo Quesada, Artur Yarulin

The structure sensitivity of acetylene hydrogenation on catalysts with controlled shape of palladium nanoparticles was studied. Palladium particles of cubic (Pd-cub), cuboctahedral (Pd-co) and octahedral (Pd-oct) shapes were obtained by a colloidal method. ...

SP MAIK Nauka/Interperiodica, Springer2012

Development of Catalytic Umpolung : Part 1: Direct Alkynylation of Heterocycles and Electron-Rich Aromatics using Alkynyl-Benziodoxolones - Part 2: Synthesis of New Bifunctional (Thio)urea-Carbene Catalysts

Jonathan Brand

The development of efficient synthetic methodologies is crucial to access complex molecules in an economic, eco-friendly and safe way. The reversal of the intrinsic reactivity of functional groups, called Umpolung, allows alternative synthetic strategies a ...

EPFL2012

Comparative evaluation of particle properties, formation of reactive oxygen species and genotoxic potential of tungsten carbide based nanoparticles in vitro

Kristin Schirmer

Tungsten carbide (WC) and cobalt (Co) are constituents of hard metals and are used for the production of extremely hard tools. Previous studies have identified greater cytotoxic potential of WC-based nanopartides if particles contained Co. The aim of this ...

Elsevier Science Bv2012

New Acetylene Chemistry : Direct [alpha]-Alkynylation of Carbonyls with Ethynyl Benziodoxolones (EBX)

Davinia Fernández González

This thesis is divided in seven main chapters including an introduction about the state of the art in the field, four main chapters describing the main part of the work, a short insight on the implications of the presented results for other research projec ...

EPFL2011

Monodispersed Pd Nanoparticles for Acetylene Selective Hydrogenation: Particle Size and Support Effects

Lioubov Kiwi, Marina Ruta

Monodispersed Pd nanoparticles (8, 11, and 13 nm in iameter) as confirmed by high resolution transmission electron microscopy were prepared via the reverse microemulsion method and deposited on structured supports consisting of carbon nanofibers (CNF) grow ...

2008

Multiscale modeling of crowdion and vacancy defects in body-centered-cubic transition metals

We investigate the structure and mobility of single self-interstitial atom and vacancy defects in body-centered-cubic transition metals forming groups 5B (vanadium, niobium, and tantalum) and 6B (chromium, molybdenum, and tungsten) of the Periodic Table. D ...

2007

Optical properties of metal-doped carbon based nanocomposite thin films: Comparing experiment to effective medium theories

Josef Andreas Schuler

Nanocomposite thin films exhibit interesting optical properties which differ from those of the pure constituents. Effective medium theories are used to model the dielectric function of the nanocomposite materials. We give an introduction to the theories of ...

2006

Low-dimensional supramolecular architectures at metal surfaces

Sebastian Stepanow

This thesis is concerned with supramolecular architectures assembled at metal surfaces. The investigations pursued two objectives. On the one hand, the focus was placed on the fabrication of low-dimensional surface-supported network structures by applying ...

EPFL2005