Publications associées à Réaction en chaîne

Heterogeneous catalysis via light-heat dual activation: A path to the breakthrough in C1 chemistry

A hybrid photothermal catalytic system, which combines both the photochemical (light) and thermal (heat) activation pathways over a bifunctional catalyst, has demonstrated remarkable levels of reaction activity and selectivity when compared with individual ...

Cell Press2024

Kinetic Network Modeling of the Catalytic Upgrading of Biomass's Acetate Fraction to Aromatics

Jeremy Luterbacher, Jher Hau Yeap, Bartosz Rozmyslowicz, Ahmed Mohamed Ibrahim Elkhaiary

The acetate fraction is the fourth most abundant fraction by weight in many plant species and can be easily extracted as acetic acid in high yields. We have previously shown that acetic acid obtained from steam pretreated beech wood could be upgraded in a ...

Amer Chemical Soc2023

Development of next-generation microfluidic systems for enhanced, faster, and cost-effective immunoassays for tissue diagnostics - Ac electrothermal flow & Acoustofluidics

Muaz Salama Abdelmonem Draz

The application of microfluidics in the field of surface-based assays and more specifically, the spatial molecular profiling of tumor tissues has gained a lot of interest, especially with the increased interest in personalized medicine and targeted therapy ...

EPFL2023

Evaluation of the role of superoxide radical as chain carrier for the formation of hydroxyl radical during ozonation

Urs von Gunten, Gang Yu, Yan Wang

Superoxide radicals (O-2(center dot-)) have been suggested as an important chain carrier in the radical chain reaction that promotes ozone (O-3) decomposition to hydroxyl radicals ((OH)-O-center dot) during ozonation. However, due to the difficulty in meas ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Improving time-resolution and sensitivity of in situ X-ray photoelectron spectroscopy of a powder catalyst by modulated excitation

Oliver Kröcher, Davide Ferri, Filippo Buttignol

Ambient pressure X-ray photoelectron spectroscopy (APXPS) is a powerful tool to characterize the surface structure of heterogeneous catalysts in situ. In order to improve the time resolution and the signal-to-noise (S/N) ratio of photoemission spectra, we ...

ROYAL SOC CHEMISTRY2023

Positive Streamer Initiation in SF6/CO2 Based on Zener's Field Ionization

Guang-Yu Sun

In this study, experiments were performed to measure the inception and breakdown voltages of SF6/CO2 mixed gases with varying mixing ratios at two different pressures (1 and 2 bar). Using the preliminary data obtained from the experiments, a 3D particle mo ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

The influence of sulfate addition on hydration kinetics and C-S-H morphology of C3S and C3S/C(3)A systems

Karen Scrivener, Franco Alberto Zunino Sommariva

A comprehensive understanding of hydration kinetics, sulfate requirement and phase assemblage of Portland cement is crucial for further optimization of early-age performance, especially when part of cement is replaced by mineral additions in blended cement ...

Pergamon-Elsevier Science Ltd2022

Hydration and mixture design of calcined clay blended cements: review by the RILEM TC 282-CCL

Karen Scrivener, Franco Alberto Zunino Sommariva, Mohsen Ben Haha, François Henri Avet, Anuj Parashar, Yuvaraj Dhandapani, Sreejith Krishnan

The RILEM technical committee 282-CCL: Calcined Clays as Supplementary Cementitious Materials, investigates all the aspects related to calcined clays, from clay exploration and characterization to calcination process, hydration reactions and concrete prope ...

SPRINGER2022

Construction of Fe3O4 bridged Pt/g-C3N4 heterostructure with enhanced solar to fuel conversion

Michael Graetzel, Shaik Mohammed Zakeeruddin

In this study, we report the effects of co-catalysts of Pt nanoparticles and Fe3O4 clusters on photocatalytic behaviors of g-C3N4 (CN) and the use of the resulting photocatalyst for CO2 photoreduction to solar fuels in a flow reactor operated at room-tempe ...

ELSEVIER2022

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

Cluster Catalysis with Lattice Oxygen: Tracing Oxygen Transport from a Magnetite (001) Support onto Small Pt Clusters

Wolfgang Harbich, Giulia Elisabetta Pacchioni, Ke Zhang

Oxidation catalysis on reducible oxide-supported small metal clusters often involves lattice oxygen. The present work aims at differentiating whether the reaction takes place at the cluster/support interface or on the cluster. To that purpose, we trace the ...

AMER CHEMICAL SOC2021

The Influence of O-2 on Positive Streamer Initiation in Supercritical CO2 With Field Ionization Using a 3-D Particle Model

Guang-Yu Sun

In this work, the influence of varying mixing ratios of O-2 on positive streamer initiation in supercritical (SC) CO2 at different applied voltages was investigated using a 3-D particle model. Zener's model was included in the 3-D particle model to calcula ...

2021

Gold-in-copper at low *CO coverage enables efficient electromethanation of CO2

Michael Graetzel, Dan Ren, Yang Li, Jun Li, Yongfeng Xie, Xiaoyan Wang, Yiping Wang, Ziyun Wang, Pengfei Ou, Yi Xu

The renewable-electricity-powered CO2 electroreduction reaction provides a promising means to store intermittent renewable energy in the form of valuable chemicals and dispatchable fuels. Renewable methane produced using CO2 electroreduction attracts inter ...

Nature Research2021

Systematic investigations of uranium carbide composites oxidation from micro- to nano-scale: Application to waste disposal

Nhât-Tân Vuong

The production of radioisotope beams at the ISOLDE (Isotope Separator OnLine DEvice) facility at CERN is achieved by irradiating target materials (e.g. uranium carbides and metal foils) with protons. The materials are usually operated at temperatures above ...

EPFL2021

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

Atomistic dynamics of elimination and nucleophilic substitution disentangled for the F- + CH3CH2Cl reaction

Eduardo Carrascosa Casado

Chemical reaction dynamics are studied to monitor and understand the concerted motion of several atoms while they rearrange from reactants to products. When the number of atoms involved increases, the number of pathways, transition states and product chann ...

NATURE PORTFOLIO2021

Asymmetric Elimination Reaction on Chiral Metal Surfaces

Harald Brune, Roland Widmer, Martina Danese, Daniele Passerone, Samuel Thomas Stolz

The production of enantiopure materials and molecules is of uttermost relevance in research and industry in numerous contexts, ranging from nonlinear optics to asymmetric synthesis. In the context of the latter, dehalogenation, which is an essential reacti ...

Wiley-V C H Verlag Gmbh2021

Highly Efficient Activation of HCl Dissociation on Au(111) via Rotational Preexcitation

Rainer Beck

The probability for dissociation of molecules on metal surfaces, which often controls the rate of industrially important catalytic processes, can depend strongly on how energy is partitioned in the incident molecule. There are many example systems where th ...

2021

High-order geometric integrators for representation-free Ehrenfest dynamics

Jiri Vanicek, Seonghoon Choi

Ehrenfest dynamics is a useful approximation for ab initio mixed quantum-classical molecular dynamics that can treat electronically nonadiabatic effects. Although a severe approximation to the exact solution of the molecular time-dependent Schrödinger equa ...

2021

Dissipation-Driven Selection under Finite Diffusion: Hints from Equilibrium and Separation of Time Scales

Paolo De Los Rios, Shiling Liang, Daniel Maria Busiello

When exposed to a thermal gradient, reaction networks can convert thermal energy into the chemical selection of states that would be unfavourable at equilibrium. The kinetics of reaction paths, and thus how fast they dissipate available energy, might be do ...

MDPI2021