A5000126422- Catalytic Processes in Materials Science
- Catalysts for Methane Reforming
- Catalysis and Oxidation Reactions
- Nanomaterials for catalytic reactions
- Electrocatalysts for Energy Conversion
- Layered Double Hydroxides Synthesis and Applications
- Advanced battery technologies research
- X-ray Diffraction in Crystallography
- Catalysis and Hydrodesulfurization Studies
- Ammonia Synthesis and Nitrogen Reduction
- Crystal Structures and Properties
- Mesoporous Materials and Catalysis
- Crystallization and Solubility Studies
- Advancements in Battery Materials
- Carbon dioxide utilization in catalysis
- Hydrogen Storage and Materials
- ZnO doping and properties
- Copper-based nanomaterials and applications
- Iron oxide chemistry and applications
- Electrochemical Analysis and Applications
- Oxidative Organic Chemistry Reactions
- nanoparticles nucleation surface interactions
- Catalysis for Biomass Conversion
- Gas Sensing Nanomaterials and Sensors
- Supercapacitor Materials and Fabrication
Kiel University
2003-2025
Institute of Inorganic Chemistry of the Slovak Academy of Sciences
2025
Clinical Research Center Kiel
2025
Interface (United Kingdom)
2025
University of Duisburg-Essen
2015-2024
Czech Academy of Sciences, Institute of Inorganic Chemistry
2024
Gwangju Institute of Science and Technology
2012-2023
Fritz Haber Institute of the Max Planck Society
2009-2018
Essen University Hospital
2016
SLAC National Accelerator Laboratory
2015
One of the main stumbling blocks in developing rational design strategies for heterogeneous catalysis is that complexity catalysts impairs efforts to characterize their active sites. We show how identify crucial atomic structure motif industrial Cu/ZnO/Al(2)O(3) methanol synthesis catalyst by using a combination experimental evidence from bulk, surface-sensitive, and imaging methods collected on real high-performance catalytic systems with density functional theory calculations. The site...
In situ neutron diffraction was used to study the structural properties of an industrial ammonia synthesis catalyst under working conditions similar those Haber–Bosch process. Despite favorable thermodynamics, no indications reversible bulk nitridation iron observed in a self-generated concentration 12 vol % at 425 °C and 75 bar after 88 h on stream. As service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be...
In industrially relevant Cu/ZnO/Al2 O3 catalysts for methanol synthesis, the strong metal support interaction between Cu and ZnO is known to play a key role. Here we report detailed chemical transmission electron microscopy study on nanostructural consequences of in an activated high-performance catalyst. For first time, clear evidence formation metastable "graphite-like" layers during reductive activation provided. The description this layer might contribute understanding synergistic...
Abstract Methanol, an important chemical, fuel additive, and precursor for clean fuels, is produced by hydrogenation of carbon oxides over Cu‐based catalysts. Despite the technological maturity this process, understanding apparently simple reaction still incomplete with regard to mechanism active sites. Regarding latter, recent progress has shown that stepped ZnO x ‐decorated Cu surfaces are crucial performance industrial Herein, we integrate insight additional experiments into a full...
The intermetallic compounds Pd3Ga7, PdGa, and Pd2Ga are found to be highly selective semihydrogenation catalysts for acetylene outperforming established systems. stability of the crystal electronic structure under reaction conditions allows direct relation structural catalytic properties a knowledge-based development new catalyst In PdGa palladium is exclusively surrounded by gallium atoms. alteration Pd coordination in leads strong modification around Fermi level comparison elemental Pd....
H/D exchange experiments on a Cu/ZnO/Al2O3 catalyst have shown that methanol synthesis and RWGS display strong thermodynamic isotope effect, which is attributed to differences in the zero-point energy of hydrogenated vs. deuterated species. The effect larger for substantially increases equilibrium yield syngas. In kinetic regime CO2 hydrogenation, an inverse substitution was observed, stronger than CO formation suggesting two reactions do not share common intermediate. Similar observations...
The promoting effect of Al, Ga, and Mg on the support in Cu/ZnO catalysts for methanol synthesis has been investigated. Different unpromoted promoted ZnO supports were synthesized impregnated with Cu metal a subsequent step. All materials, supports, calcined activated characterized by various methods, including contactless (microwave) conductivity measurements under different gas atmospheres. Small amounts promoters found to exhibit significant influence properties oxide support, concerning...
Abstract Discussed are the recent experimental and theoretical results on palladium‐based catalysts for selective hydrogenation of alkynes obtained by a number collaborating groups in joint multi‐method multi‐material approach. The critical modification catalytically active Pd surfaces incorporation foreign species X into sub‐surface metal was observed situ spectroscopy X=H, C under conditions. Under certain conditions (low H 2 partial pressure) alkyne fragmentation leads to formation PdC...
Addition of small amounts promoters to solid catalysts can cause pronounced improvement in the catalytic properties. For complex employed industrial processes, fate and mode operation is often not well understood, which hinders a more rational optimization these important materials. Herein we show for example Cu/ZnO/Al2O3 catalyst methanol synthesis how structure-performance relationships deliver such insights shed light on role Al promoter this system. We were able discriminate structural...
Abstract The Tauc plot is a method originally developed to derive the optical gap of amorphous semiconductors such as germanium or silicon. By measuring absorption coefficient α ( hν ) and plotting versus photon energy , value for determined. In this way non‐direct transitions between approximately parabolic bands can be examined. last decades, modification (poly‐) crystalline has become popular study direct indirect interband transitions. For purpose, ahν n = 2) plotted against determine...
Spinel-type catalysts are promising anode materials for the alkaline oxygen evolution reaction (OER), exhibiting low overpotentials and providing long-term stability. In this study, we compared two structurally equal Co2FeO4 spinels with nominally identical stoichiometry substantially different OER activities. particular, one of samples, characterized by a metastable precatalyst state, was found to quickly achieve its steady-state optimum operation, while other, which initially closer ideal...
Abstract Ammonia is a storage molecule for hydrogen, which can be released by catalytic decomposition. Inexpensive iron catalysts suffer from low activity due to too strong iron-nitrogen binding energy compared more active metals such as ruthenium. Here, we show that this limitation overcome combining with cobalt resulting in Fe-Co bimetallic catalyst. Theoretical calculations confirm lower metal-nitrogen the catalyst higher activity. Operando spectroscopy reveals role of suppress...
The design of solid catalysts for industrial processes remains a major challenge in synthetic materials chemistry. Based on the investigation Cu/ZnO/Al2O3 catalyst, modular concept is introduced that helps to develop novel methanol synthesis operate different feed gas mixtures. SA=surface area, SMSI=strong metal–support interaction.
A series of hydrotalcite-like (htl) compounds the general composition (Cu,Zn)1−xAlx(OH)2(CO3)x/2·m H2O was prepared with a fixed Cu:Zn ratio 70:30. Phase pure samples could be obtained for 0.3 ≤ x 0.4. The htl precursors thermally decompose in multiple steps. After dehydration and dehydroxylation amorphous materials were at 330 °C. segregation during this mild calcination only observed Zn:Al deviating strongly from 1:2. mechanism low-temperature process basing on preformation ZnAl2O4 phase...
Abstract Incipient wetness impregnation and a novel deposition symproportionation precipitation were used for the preparation of MnO x /CNT electrocatalysts efficient water splitting. Nanostructured manganese oxides have been dispersed on commercial carbon nanotubes as result both methods. A strong influence history electrocatalytic performance was observed. The as‐prepared state 6.5 wt. % sample could be comprehensively characterized by comparison to an unsupported reference sample. Various...
Abstract In this research report we summarize recent progress that has been made in the field of Cu/ZnO catalyst synthesis. We briefly introduce fields application catalyst: methanol synthesis, water gas shift reaction, and steam reforming. The review is focused on well‐documented industrial synthesis protocol early stages setting most critical parameters during co‐precipitation ageing, like pH temperature, discussed detail. show how these effect phase formation identify zincian malachite,...
Abstract In industrially relevant Cu/ZnO/Al 2 O 3 catalysts for methanol synthesis, the strong metal support interaction between Cu and ZnO is known to play a key role. Here we report detailed chemical transmission electron microscopy study on nanostructural consequences of in an activated high‐performance catalyst. For first time, clear evidence formation metastable “graphite‐like” layers during reductive activation provided. The description this layer might contribute understanding...
Abstract Long‐term stability of catalysts is an important factor in the chemical industry. This often underestimated academic testing methods, which may lead to a time gap field catalytic research. The deactivation behavior industrially relevant Cu/ZnO/Al 2 O 3 catalyst for synthesis methanol reported over period 148 days time‐on‐stream (TOS). process was investigated by combination quasi situ and ex analysis techniques. results show that ZnO most dynamic species catalyst, whereas only...
Dry reforming of methane (DRM) has been studied for many years as an attractive option to produce synthesis gas. However, catalyst deactivation by coking over nonprecious-metal catalysts still remains unresolved. Here, we study the influence structural and compositional properties nickel on catalytic performance propensity in DRM. A series bulk with different Ni contents was synthesized calcination hydrotalcite-like precursors NixMg0.67–xAl0.33(OH)2(CO3)0.17·mH2O prepared constant-pH...
Different surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity probe molecules, assuming they specifically react with unique sites. In case methanol synthesis catalysts, Cu area is one crucial parameters in catalyst design and was for over 25 years commonly determined using diluted N2O. To disentangle influence components, different model were prepared characterized N2O, temperature programmed desorption H2, kinetic...