Publications associées à Energy and orientation independence of the channel branching in Ne* + ND3 chemi-ionisation

Monomeric Fe Species in Square Planar Geometry Active for Low Temperature NH3-SCR of NO

Monomeric Fe species in zeolites are considered to be the active sites for the low temperature activity toward ammonia-assisted selective catalytic reduction of nitrogen oxides (NH3-SCR) in exhaust gases. Herein, we report on a preparation method to synthe ...

AMER CHEMICAL SOC2022

Studies of cold chemistry in crossed and merged neutral beams

Silvia Tanteri

In this thesis we present the design of two setups to study low-energy collisions between neutral species: an electron velocity map imaging for chemi-ionisation reactions and a merged electrostatic guide for polar molecules scattering. In the past few yea ...

EPFL2021

Low-energy stereodynamics of ion-forming reactions

Junwen Zou

In this thesis, an experimental study of low-temperature stereodynamics in the reactive scattering of Ne(3P2) + X collisions (X = Ar, Kr, Xe, CO and N2) is presented. The steric effect of Ne(3P2) in these reactions is observed experimentally using a contro ...

EPFL2021

Study of He/Ne+Ar, Kr, N2, H2, D2 Chemi-Ionization Reactions by Electron Velocity-Map Imaging

Andreas Osterwalder, Junwen Zou, Sean Dennis Steven Gordon, Silvia Tanteri

The chemi-ionization of Ar, Kr, N2, H2, and D2 by Ne(3P2) and of Ar, Kr, and N2 by He(3S1) was studied by electron velocity map imaging (e-VMI) in a crossed molecular beam experiment. A curved magnetic hexapole was used to state-select the metastable speci ...

2021

Hydrogen Bonding of Ammonia with (H,OH)-Si(001) Revealed by Experimental and Ab Initio Photoelectron Spectroscopy

Alfredo Pasquarello, Oleg Yazyev

Combining experimental and ab initio core-level photoelectron spectroscopy (periodic DFT and quantum chemistry calculations), we elucidated how ammonia molecules bond to the hydroxyls of the (H,OH)-Si(001) model surface at a temperature of 130 K. Indeed, t ...

AMER CHEMICAL SOC2020

The stereodynamics of ion forming reactions

Andreas Osterwalder, Sean Dennis Steven Gordon

Energy transfer reactions occur in all areas of chemistry. One fundamental form of this is demonstrated by reactions in which an electronically excited atom transfers energy to a neutral, resulting in spontaneous ionisation, potentially combined with compl ...

2020

Investigation of the low-energy stereodynamics in the Ne(3P2) + N2, CO reactions

Andreas Osterwalder, Junwen Zou

We report on an experimental investigation of the low-energy stereodynamics of the energy transfer reactions Ne(3P2) + X, producing Ne(1S) + X+ and [Ne–X]+ (X = N2 or CO). Collision energies in the range 0.2 K–700 K are obtained by using the merged beam te ...

2020

Charge transfer dynamics in Ar+ + CO

Eduardo Carrascosa Casado

Differential cross sections for the charge transfer reaction between Ar(+)and CO have been measured using three-dimensional velocity map imaging in a crossed beam setup at the two relative collision energies 0.55 and 0.74 eV. We find dominant forward scatt ...

Taylor & Francis2020

Unexpected Indirect Dynamics in Base-Induced Elimination

Eduardo Carrascosa Casado

Base-induced elimination (E2) and bimolecular nucleophilic substitution (S(N)2) are two of the most versatile reactions that are important in preparative organic chemistry. These stereospecific reactions are often found in direct competition with each othe ...

AMER CHEMICAL SOC2019

Gas-Phase Ozone Reactions with a Structurally Diverse Set of Molecules: Barrier Heights and Reaction Energies Evaluated by Coupled Cluster and Density Functional Theory Calculations

Jeremy Samuel Arey, Peter Rudolf Tentscher, Daniela Trogolo

Reactions with ozone transform organic and inorganic molecules in water treatment systems as well as in atmospheric chemistry, either in the aqueous phase, at gas/particle interfaces, or in the gas phase. Computed thermokinetic data can be used to estimate ...

AMER CHEMICAL SOC2019

Organocatalysts in C-N Bond Forming Reactions of Amines with CO2

Martin Hulla

The thesis describes a simple approach for N-formylation of amines with CO2 and hydrosilane reducing agents, the use of organic salts as N-formylation catalysts, their physical properties required for high catalytic activity and their role in the catalytic ...

EPFL2019

Improved Alkali Intercalation of Carbonaceous Materials in Ammonia Solution

László Forró, Bálint Náfrádi, Péter Szirmai, Ferenc Simon, Sándor Kollarics, Bence Gábor Márkus

Alkali-intercalated graphite compounds represent a compelling modification of carbon with significant application potential and various fundamentally important phases. The intercalation of graphite with alkali atoms (Li and K) using liquid ammonia solution ...

WILEY-V C H VERLAG GMBH2019

Quantum-state-controlled channel branching in cold Ne(3P2)+Ar chemi-ionization

Andreas Osterwalder, Junwen Zou, Sean Dennis Steven Gordon, Silvia Tanteri

A prerequisite to gain a complete understanding of the most basic aspects of chemical reactions is the ability to perform experiments with complete control over the reactant degrees of freedom. By controlling these, details of a reaction mechanism can be i ...

2018

Nitrogen reduction and functionalization by a multimetallic uranium nitride complex

Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Lucile Sylvie Danielle Chatelain, Marta Falcone

Molecular nitrogen (N-2) is cheap and widely available, but its unreactive nature is a challenge when attempting to functionalize it under mild conditions with other widely available substrates (such as carbon monoxide, CO) to produce value-added compounds ...

2017

Transition metal clusters on h-BN/Rh(111) : surface interaction and catalytic activity

Hamed Achour

The main aim of this dissertation is to study the catalytic aspects of very small transition metal clusters supported on h-BN/Rh(111). The catalytic reactions of interest were ammonia synthesis and CO oxidation on mass selected and soft landed iron and pla ...

EPFL2017

Reaction extents: A Divide-and-Conquer Approach for Kinetic Model Identification

Dominique Bonvin, Julien Léo Billeter

Obtaining reliable wastewater treatment process models is critical for the application of model-based design, operation, and automation. For example, Masic et al. (2014) explored the use of an observer designed for nonlinear processes to estimate nitrite i ...

2017

Experimental and Theoretical Studies of Low-Energy Penning Ionization of NH3, CH3F, and CHF3

Andreas Osterwalder, Justinas Jankunas

We present results from a joint theoretical and experimental study of the low-energy Penning ionization of NH3, CH3F, and CHF3 by metastable Ne(P-3(2)) and He(S-3(1)) atoms. We combine the merged neutral beams experiment, covering a range of collision ener ...

Wiley-Blackwell2016

Importance of rotationally inelastic processes in low-energy Penning ionization of CHF3

Andreas Osterwalder, Justinas Jankunas

Low energy reaction dynamics can strongly depend on the internal structure of the reactants. The role of rotationally inelastic processes in cold collisions involving polyatomic molecules has not been explored so far. Here we address this problem performin ...

American Institute of Physics2016

Study of the Ne(3P2) + CH3F Electron-Transfer Reaction below 1 K

Andreas Osterwalder, Benjamin Bertsche, Justinas Jankunas

Relatively little is known about the dynamics of electron-transfer reactions at low collision energy. We present a study of Penning ionization of ground-state methyl fluoride molecules by electronically excited neon atoms in the 13 μeV–4.8 meV (150 mK–56 K ...

Amer Chemical Soc2014

Electrochemical behavior of ammonia at Ni/Ni(OH)2 electrode

Christos Comninellis, Agnieszka Kapalka

The electrochemical oxidation of ammonia was investigated on a Ni/Ni(OH)(2) electrode prepared by potential cycling of a Ni electrode in 1 M NaClO4. It was found that oxidation of ammonia is strongly pH dependent and proceeds mainly at pH values above 7. T ...

Elsevier2010