Publications associées à Superacide

Arylative Ring Expansion of 3-Vinylazetidin-3-Ols and 3-Vinyloxetan-3-Ols to Dihydrofurans by Dual Palladium and Acid Catalysis

In contrast to the well-studied 1-vinylcyclobu- tanols, the reactivity of 3-vinylazetidin-3-ols 1 and 3- vinyloxetan-3-ols 2 under transition metal catalysis remains largely unexplored. We report herein their unique reactivity under dual palladium and acid ...

Wiley-VCH Verlag GmbH2024

Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere

Andrea Baccarini, Imad El Haddad, Mihnea Surdu, Lubna Dada, André Welti, Houssni Lamkaddam

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid ...

American Association for the Advancement of Science2023

Effect of an Al2O3-based binder on the structure of extruded Fe-ZSM-5

Oliver Kröcher, Davide Ferri, Pierdomenico Biasi, Filippo Buttignol

The effect of an alumina-based binder on the structure of a commercial Fe-ZSM-5 catalyst has been investigated. Several ex-situ characterization techniques were used to show that the binder in the catalyst formulation allows obtaining a material that posse ...

ELSEVIER2022

Synthetic chemistry with nitrous oxide and triazenes

Iris Roswitha Landman

Nitrous oxide (N2O) has gained much interest because of its physiological effects ("laughing gas") and its negative environmental impact ("greenhouse gas", "ozone-depleting substance"): It has a lifetime of more than 100 years in the atmosphere. Its persis ...

EPFL2022

Recent Advances in Group 14 and 15 Lewis Acids for Frustrated Lewis Pair Chemistry

Shubhajit Das

Frustrated Lewis pairs (FLP) which rely on the cooperative action of Lewis acids and Lewis bases, played a prominent role in the advancement of main-group catalysis. While the early days of FLP chemistry witnessed the dominance of boranes, there is a growi ...

WILEY-V C H VERLAG GMBH2022

Aging of industrial Fe-zeolite based catalysts for nitrous oxide abatement in nitric acid production plants

Oliver Kröcher, Davide Ferri, Pierdomenico Biasi, Filippo Buttignol

The influence of hydrothermal aging on the structural and catalytic properties of two commercial Fe-exchanged zeolite catalysts (Fe-FER and Fe-ZSM-5) in the extruded form employed for the removal of N2O from the exhaust of nitric acid production plants has ...

ROYAL SOC CHEMISTRY2022

Advances in heterogeneous catalysis for the synthesis of polyoxymethylene dimethyl ethers

Christophe Jean Baranowski

Our society is engaged in a major shift towards more sustainable industries. The required transition from fossils to renewable resources with low greenhouse gas emission is specifically challenging in the transportation sector where high thermal efficiency ...

EPFL2020

Nature of Synergy between Bronsted and Lewis Acid Sites in Sn-Beta Zeolites for Polyoxymethylene Dimethyl Ethers Synthesis

Oliver Kröcher, Alimohammad Bahmanpour, Christophe Jean Baranowski

The role of Lewis and Bronsted acid sites and their potential synergy remains ambiguous for the production of polyoxymethylene dimethyl ethers (OME), which are suitable as a Diesel substitute. Here, this synergistic effect was investigated by using a serie ...

WILEY-V C H VERLAG GMBH2019

Post-synthesis deposition of mesoporous niobic acid with improved thermal stability by kinetically controlled sol–gel overcoating

Jeremy Luterbacher, Florent Emmanuel Héroguel, Yuan-Peng Du

Niobia is a well-known solid acid catalyst owing to its intrinsic Brønsted and Lewis acidity. However, catalyst development with this oxide has been limited by our ability to control its pore structure and thermal stability. Here we report a novel post-syn ...

Royal Society of Chemistry2019

Enhanced mineralization of atrazine by surface induced hydroxyl radicals over light-weight granular mixed-quartz sands with ozone

Stefanos Giannakis, Jun Ma, Da Wang, Shuang Song

A light-weight granular mixed-quartz sand (denoted as L-GQS) combined with stirring-assisted bubble column reactor was firstly applied in catalytic ozonation of atrazine. The L-GQS, with a density of 2.36 g cm(-3) and average diameter of ca. of 4 mm, was r ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Mechanochemistry-assisted hydrolysis of softwood over stable sulfonated carbon catalysts in a semi-batch process

Frédéric Vogel, Oliver Kröcher, David Ferdinand Scholz

The hydrolysis of lignocellulose is the first step in saccharide based bio-refining. The recovery of homogeneous acid catalysts imposes great challenges to the feasibility of conventional hydrolysis processes. Herein, we report a strategy to overcome these ...

2019

Method for synthesis of a metal organic framework composite

Wendy Lee Queen, Daniel Teav Sun, Shuliang Yang, Li Peng

The present invention relates to a method for synthesis of a metal organic framework composite comprising the folowing steps: a) Synthesize a metal organic framework; b) Make a polymer grow on said metal organic framework, said polymer being chosen among p ...

2019

Hydrothermally Stable Sulfonated Carbons as Solid Acid Catalysts for the Hydrolysis of Lignocellulose

David Ferdinand Scholz

The recycling of homogeneous acids imposes great challenges to the feasibility of lignocellulose hydrolysis processes. Although heterogeneous catalysts would offer a perspective to circumvent these challenges, conventional solid acids are instable under th ...

EPFL2019

Effects of water-soluble organic carbon on aerosol pH

Athanasios Nenes

Water-soluble organic carbon (WSOC) is a ubiquitous and significant fraction of fine particulate matter. Despite advances in aerosol thermodynamic equilibrium models, there is limited understanding on the comprehensive impacts of WSOC on aerosol acidity (p ...

Copernicus GmbH2019

Thermal activation and aging of a V2O3/WO3-TiO2 catalyst for the selective catalytic reduction of NO with NH3

Oliver Kröcher, Davide Ferri, Adrian Marberger, Rob Jeremiah G. Nuguid

Real-world vanadium-based catalysts for the selective catalytic reduction (SCR) of NO with NH3 are occasionally exposed to high temperatures, which can induce catalyst aging. In this work, a 2.0 wt% V2O5/WO3-TiO2 catalyst based on commercial WO3-TiO2 was l ...

ELSEVIER SCIENCE BV2019

Selective Catalytic Reduction of NOx

Oliver Kröcher

The deactivation pathways of sulfonated carbon catalysts prepared from different carbons were studied during the aqueous‐phase hydrolysis of cellobiose under continuous‐flow conditions. The sulfonation of carbon materials with a low degree of graphitizatio ...

2018

Deactivation and Regeneration of Sulfonated Carbon Catalysts in Hydrothermal Reaction Environments

Oliver Kröcher, Frédéric Vogel

The deactivation pathways of sulfonated carbon catalysts prepared from different carbons were studied during the aqueous‐phase hydrolysis of cellobiose under continuous‐flow conditions. The sulfonation of carbon materials with a low degree of graphitizatio ...

2018

Determining the Surface Structure of Silicated Alumina Catalysts via Isotopic Enrichment and Dynamic Nuclear Polarization Surface-Enhanced NMR Spectroscopy

David Lyndon Emsley, Brennan James Walder, Jasmine Viger-Gravel

Isotopic enrichment of Si-29 and DNP-enhanced NMR spectroscopy are combined to determine the detailed surface structure of a silicated alumina catalyst. The significant sensitivity enhancement provided by DNP is vital to the acquisition of multinuclear and ...

American Chemical Society2017

Dynamics of methane dissociation on transition metals

Rainer Beck

One of the many contributions of Harold Winters to surface science was his pioneering ultrahigh vacuum study on the kinetics of the technologically important dissociation of CH4 on transition metals in the 1970s. He observed a dramatic activation of the di ...

A V S Amer Inst Physics2017

Quantum state resolved molecular beam reflectivity measurements: CH4 dissociation on Pt(111)

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

The King and Wells molecular beam reflectivity method has been used for a quantum state resolved study of the dissociative chemisorption of CH4 on Pt(111) at several surface temperatures. Initial sticking coefficients were measured for incident CH4 prepare ...

American Institute of Physics2016