Publications de Oliver Kröcher

Modeling of the Performance Loss due to Catalyst Deactivation in Fixed- and Fluidized-Bed Reactors

A method to assess the impact of deactivation phenomena on the global performance of a catalytic reactor was developed. The methodology is applied here to the case of CO methanation, where the catalyst is subject to deactivation by coking. This method can ...

American Chemical Society (ACS)2025

N2O Activation and NO Adsorption Control the Simultaneous Conversion of N2O and NO Using NH3 over Fe-ZSM-5

Oliver Kröcher, Filippo Buttignol

Fe-exchanged zeolites are heterogeneous catalysts that can potentially ensure simultaneous conversion of nitrous oxide (N2O) and nitric oxide (NO) using ammonia (NH3) as a selective reducing agent through their selective catalytic reduction reaction (N2O-N ...

AMER CHEMICAL SOC2025

Monomeric Fe in Six-Membered Rings at Work: Operando Spectroscopy of Nitrous Oxide Activation and Decomposition over Fe-Exchanged Zeolites

Oliver Kröcher

The heterogeneous speciation of ion-exchanged zeolites hinders a rational understanding of their reactivity. This is particularly the case for Fecontaining zeolites that are widely used in both the activation and decomposition of N 2 O. Herein, we explored ...

American Chemical Society (ACS)2025

Toward Improved Exhaust Emission Control of Stoichiometric Engines by Intentional Oxygen Dithering

Oliver Kröcher

Methane emissions from the exhaust gas of stoichiometric engines can be efficiently controlled by means of three-way catalysts. In this work, we show how the activity of a fully formulated commercial three-way catalyst can be significantly enhanced by peri ...

American Chemical Society (ACS)2025

Correlating the Nature of Carbenium Ions in Zeolites to the Product Distribution in the Methanol-to-Olefins Process

Oliver Kröcher

The methanol-to-olefins (MTO) process on zeolite-based catalysts enables the production of olefins from green methanol. Selectivity control requires an understanding of the nature and evolution of hydrocarbon species that act as catalytically active center ...

AMER CHEMICAL SOC2024

The effect of Ni- and Mo-based materials on thermochemical sulfate reduction by glycerol under hydrothermal process conditions

Oliver Kröcher

Catalytic hydrothermal gasification (cHTG) is a sustainable and promising route to convert wet biomass into renewable methane, but the catalyst is deactivated by small amounts of soluble sulfate stemming from the biomass feedstock. Under hydrothermal condi ...

Elsevier2024

Iron-catalysed cooperative redox mechanism for the simultaneous conversion of nitrous oxide and nitric oxide

Oliver Kröcher, Filippo Buttignol

Iron-exchanged zeolites are often deployed industrially to remediate nitric oxide (NO) and nitrous oxide (N2O) emissions. The nature of the active site and the reaction mechanism involved in the simultaneous removal of NO and N2O remain largely unknown, pr ...

NATURE PORTFOLIO2024

Critical Aspects in the Catalytic Emission Control of Exhaust Gases Containing NH3, NOx and N2O

Oliver Kröcher, Davide Ferri

Ammonia (NH3) is a promising fuel for use in marine applications due to its favorable chemical properties. However, emissions of especially nitrous oxide (N2O), with a global warming potential (GWP) of 273, pose a significant barrier to the adoption of NH3 ...

Cardiff University Press2024

Thermal Sintering and Phosphorus Poisoning of a Layered Diesel Oxidation Catalyst

Oliver Kröcher, Davide Ferri

The tightening emission regulations have led to the development of commercial DOCs with zoned or layered formulations allowing to cover a wide range of functionalities (i.e. CO, HC and NO oxidation as well as HC or NOx trap). Aging phenomena in such comple ...

SPRINGER/PLENUM PUBLISHERS2023

Electrochemical synthesis of propylene from carbon dioxide on copper nanocrystals

Michael Graetzel, Shaik Mohammed Zakeeruddin, Oliver Kröcher, Alimohammad Bahmanpour, Dan Ren, Jing Gao

The conversion of carbon dioxide to value-added products using renewable electricity would potentially help to address current climate concerns. The electrochemical reduction of carbon dioxide to propylene, a critical feedstock, requires multiple C-C coupl ...

NATURE PORTFOLIO2023

Stability and Reactivity of a Polyoxymethylene Dimethyl Ether over Typical Catalysts for Diesel Emission Control (vol 15, pg 848, 2022)

Oliver Kröcher, Davide Ferri

SPRINGER/PLENUM PUBLISHERS2023

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

Stability and Reactivity of a Polyoxymethylene Dimethyl Ether over Typical Catalysts for Diesel Emission Control

Oliver Kröcher, Davide Ferri

Polyoxymethylene dimethyl ethers (OME) produced from methanol are considered as potential substitutes of Diesel fuel. Emissions of formaldehyde and other components have been observed, particularly under cold-start conditions in engine test-bench experimen ...

SPRINGER/PLENUM PUBLISHERS2023

Correction: 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

Correction for 'Improving time-resolution and sensitivity of in situ X-ray photoelectron spectroscopy of a powder catalyst by modulated excitation' by M. Roger et al., Chem. Sci., 2023, 14, 7482-7491, https://doi.org/10.1039/D3SC01274C. ...

ROYAL SOC CHEMISTRY2023

Preparation, Quantification, and Reaction of Pd Hydrides on Pd/ Al2O3 in Liquid Environment

Thibault Xavier Florian Fovanna, Oliver Kröcher

The ability to study in situ the formation and consumption of Pd hydrides (PdH) in liquid environments is a significant challenge hampering a deeper understanding of catalyzed liquid-phase hydrogenation reactions. Here, using quick scanning X-ray absorptio ...

AMER CHEMICAL SOC2023

Origin of the Activity Trend in the Oxidative Dehydrogenation of Ethanol over VOx/CeO2

Oliver Kröcher, Rob Jeremiah G. Nuguid, Anna Zabilska, Olga Safonova

Supported vanadia (VOx) is a versatile catalyst for various redox processes where ceria-supported VOx have shown to be particularly active in the oxidative dehydrogenation (ODH) of alcohols. In this work, we clarify the origin of the volcano-shaped ethanol ...

Wiley-VCH Verlag GmbH2023

Recent progress in calcium looping integrated with chemical looping combustion (CaL-CLC) using bifunctional CaO/CuO composites for CO2 capture: A state-of-the-art review

Oliver Kröcher, Hui Zhou, Hongyu Zhu, Muhammad Awais Naeem, Yuxin Ma

Calcium looping integrated with chemical looping combustion (CaL-CLC) process is an efficient and cost-effective CO2 capture technology. In this technique, the heat generated by chemical looping combustion of CuO is used insitu to calcine CaCO3, thus avoid ...

ELSEVIER SCI LTD2023

Assessing the effect of O2 dithering on CH4 oxidation on Pd/Al2O3

Oliver Kröcher, Davide Ferri

Under periodic lean/rich operation generated by repeated O2 pulses (O2-dithering), the abatement of CH4 and NO is enhanced compared to static operation. However, it is not well understood how the dithering parameters (pulse amplitude and frequency) affect ...

ELSEVIER SCIENCE SA2023

Swiss Energy System 2050: Pathways to Net Zero CO2 and Security of Supply - Basic report

Jean-Louis Scartezzini, Andrea Baranzini, Oliver Kröcher

This report aims at assessing pathways and formulating recommendations for the transformation of the Swiss energy system necessary to achieve the net zero greenhouse gas (GHG) emission target by 2050 (BFE 2017a) set by the Federal Council taking into accou ...

Swiss Academies of Arts and Sciences2022

Poisoning of Mn-Ce/AC catalysts for low-temperature NH3-SCR of NO by K+ and its counter-ions (Cl- /NO3- /SO42- )

Oliver Kröcher, Jie Yang, Davide Ferri, Rob Jeremiah G. Nuguid

Mn-Ce/AC catalysts for low-temperature NH3-SCR of NOx were deliberately loaded with various potassium salts (KCl, KNO3, and K2SO4) to investigate the influence of the counter-ions on the poisoning impact. Whereas K salts poisoning had only marginal impact ...

ELSEVIER2022