FG Technische Chemie

63 Items

Recent Submissions
Graphene Quantum Dot-Based Electrochemical Immunosensors for Biomedical Applications

Mansuriya, Bhargav D. ; Altintas, Zeynep (2019-12-23)

In the area of biomedicine, research for designing electrochemical sensors has evolved over the past decade, since it is crucial to selectively quantify biomarkers or pathogens in clinical samples for the efficacious diagnosis and/or treatment of various diseases. To fulfil the demand of rapid, specific, economic, and easy detection of such biomolecules in ultralow amounts, numerous nanomateria...

Surface-sensitive adsorption of water and carbon dioxide on magnetite

Zaki, Eman Ahmed Ahmed Mohammed (2020)

The interaction of water with solid surfaces is important in many scientific fields such as corrosion, electrochemistry, geology, and heterogeneous catalysis. Chemistry at water/oxide interfaces plays a crucial role in surface's properties and reactivity. Employing model systems structurally and electronically characterized under well-defined conditions offers deep insights into the chemistry o...

Nanomaterials for Healthcare Biosensing Applications

Pirzada, Muqsit ; Altintas, Zeynep (2019-12-02)

In recent years, an increasing number of nanomaterials have been explored for their applications in biomedical diagnostics, making their applications in healthcare biosensing a rapidly evolving field. Nanomaterials introduce versatility to the sensing platforms and may even allow mobility between different detection mechanisms. The prospect of a combination of different nanomaterials allows an ...

Structure, phase behavior, molecular dynamics and conductivity of columnar liquid crystals in the bulk state and under confinement

Yildirim, Arda (2020)

Molecules of columnar liquid crystals (CLCs) typically consisting of a rigid aromatic core and flexible alkyl chains, can form a columnar mesophase by self-assembly. This self assembly of the molecules in the columns are driven by π-π interactions among the aromatic cores, while the alkyl chains fill the intercolumnar space. Among other promising features of CLCs for applications, the character...

Development of sustainable reaction systems for the palladium-catalyzed methoxy- and hydroxycarbonylation of alkenes: Boon and bane of multiphase systems

Schmidt, Marcel (2019)

Catalysis plays a major role in chemistry. In particular, homogeneous catalysis opens the door to a sustainable synthesis of many products, offering mild reaction conditions, excellent activity as well as selectivity. However, the recycling of the expensive catalyst complexes is a major drawback, hampering the implementation of homogeneous catalysis for industrial application. Hence, alternativ...

Catalytic hydroformylation reactions in liquid-liquid multiphase systems with polymer particles and without phase transfer agents

Bibouche, Bachir (2019)

Utilizing molecular catalysts allows for selective and resource efficient reactions. One big challenge of utilizing these catalysts is their recyclability, since they often get deactivated when separating the product. This work deals with different liquid-liquid, multiphasic, reaction systems with molecular catalysts, and their recycling. In the discussed approaches, there is always an aqueous ...

Upgrading of lignocellulose-derived sugars to value-added chemicals via heterogeneously catalyzed continuous-flow processes

Bäumel, Marius (2019)

In the present work, a methodology is proposed for the synthesis of metal-based hydrogenation catalysts supported on hierarchically porous carbon pellets, which are suitable for industrial flow processes. For the preparation of the carbon support, durum semolina is used as the carbon source, in addition to ZnO nanopowder as the porogenic templating agent. Owing to their large surface area of 75...

Kinetic investigation of selective alkane activation

Schulz, Christian (2019)

Since the discovery of vanadyl pyrophosphate (VO)2P2O7 (VPP) based catalysts in the 1970s, major efforts were put in understanding the reaction network of the selective oxidation of n-butane to maleic anhydride (MAN). Although a significant improvement of the yield could be realized since then by advanced synthesis protocols, the selectivity of MAN is limited to 70% at an industrially relevant ...

Nanoparticle Enhanced Antibody and DNA Biosensors for Sensitive Detection of Salmonella

Savas, Sumeyra ; Ersoy, Aylin ; Gulmez, Yakup ; Kilic, Selcuk ; Levent, Belkis ; Altintas, Zeynep (2018-08-27)

Bacteria-related pathogenic diseases are one of the major health problems throughout the world. Salmonella is a genus of rod-shaped Gram-negative enterobacteria of which more than 2600 serotypes have been identified. Infection with Salmonella can cause salmonellosis, a serious bacterial toxi-infection syndrome associated with gastroenteritis, and paralyphoid and typhoid fevers. Its rapid and se...

Experimental Activity Descriptors for Iridium-based Catalysts for the Electrochemical Oxygen Evolution Reaction (OER)

Spöri, Camillo Wolfgang ; Briois, Pascal ; Nong, Hong Nhan ; Reier, Tobias ; Billard, Alain ; Kühl, Stefanie ; Teschner, Detre ; Strasser, Peter (2019-06-13)

Recent progress in the activity improvement of anode catalysts for acidic electrochemical water splitting was largely achieved through empirical studies of iridium-based bimetallic oxides. However, practical, experimentally accessible, yet general predictors of catalytic OER activity are lacking. This study investigates iridium and iridium-nickel thin film model electrocatalysts for the OER and...

The Stability Challenges of Oxygen Evolving Catalysts: Towards a Common Fundamental Understanding and Mitigation of Catalyst Degradation

Spöri, Camillo Wolfgang ; Kwan, Jason Tai Hong ; Bonakdarpour, Arman ; Wilkinson, David P. ; Strasser, Peter (2017-05-04)

This review addresses the technical challenges, their scientific basis, as well as recent progress and the road ahead with respect to the stability and degradation of OER catalysts operating at electrolyzer anodes in acidic environments with an emphasis on MEA based operation. First, we start clarifying the complexity associated with the term “catalyst stability”, cover today’s performance targ...

Surface Plasmon Resonance Immunosensor for the Detection of Campylobacter jejuni

Masdor, Noor Azlina ; Altintas, Zeynep ; Tothill, Ibtisam E. (2017-05-16)

Campylobacteriosis is an internationally important foodborne disease caused by Campylobacter jejuni. The bacterium is prevalent in chicken meat and it is estimated that as much as 90% of chicken meat on the market may be contaminated with the bacterium. The current gold standard for the detection of C. jejuni is the culturing method, which takes at least 48 h to confirm the presence of the bact...

Structure-stability-activity studies on low Ir content mixed metal oxides for the electrochemical water oxidation in acidic media

Spöri, Camillo Wolfgang (2019)

Today, renewable energy power plants are being installed on an increasing scale, however, their growing capacity calls for reliable high-performance storage technologies to be developed simultaneously. PEM water electrolysis is one of the key emerging technologies for chemical energy storage in form of hydrogen, which, for example, can be used in fuel cells for transportation and reconversion t...

Untersuchung von Deflagrationen selbstzersetzlicher Feststoffe und Entwicklung einer neuartigen Prüfmethode zur Beurteilung der Deflagrationsfähigkeit in geschlossenen Systemen

Salg, Steffen (2019)

Das Deflagrationsverhalten selbstzersetzlicher fester Stoffe wurde bei unterschiedlichen Randbedingungen untersucht. Darüber hinaus wurde eine neue Prüfmethode entwickelt, mit welcher das Deflagrationsverhalten in geschlossenen Systemen beurteilt werden kann. Es wurden drei neue Messsysteme mit verschiedenen Volumina und Geometrien im Labormaßstab in Betrieb genommen. Die Verwendung der neuen M...

Metal-nitrogen-doped carbon (M-N-C) catalysts for the direct electrochemical reduction of CO2 to value-added chemicals and fuels

Ju, Wen (2019)

In the past decades, the surplus of atmospheric CO2 concentration has drawn tremendous political and scientific attention for its negative impacts, such as the greenhouse effect and ocean carbonation. To mitigate such CO2 issues, a combination of various strategies is required. The electrochemical CO2 reduction reaction (CO2RR) is a promising alternative to convert CO2 into carbon-based chemica...

Model-system studies on manganese oxide-based water oxidation catalysts made with atomic layer deposition

Plate, Paul (2019)

Climate change has become the main challenge of our society. Extensive CO2 emission due to fossil fuel combustion has to be minimized to prevent severe damages to the climate system. Hence, new and sustainable energy carriers have to be explored. Hydrogen can be produced in a sustainable manner, however, current processes are not yet economically viable. Photoelectrochemical water splitting is ...

Real-time imaging of activation and degradation of carbon supported octahedral Pt–Ni alloy fuel cell catalysts at the nanoscale using in situ electrochemical liquid cell STEM

Beermann, Vera ; Holtz, Megan E. ; Padgett, Elliot ; de Araujo, Jorge Ferreira ; Muller, David A. ; Strasser, Peter (2019-05-20)

Octahedrally shaped Pt–Ni alloy nanoparticles on carbon supports have demonstrated unprecedented electrocatalytic activity for the oxygen reduction reaction (ORR), sparking interest as catalysts for low-temperature fuel cell cathodes. However, deterioration of the octahedral shape that gives the catalyst its superior activity currently prohibits the use of shaped catalysts in fuel cell devices,...

Precious metal-free bifunctional catalysts for reversible seawater electrolyzers

Dresp, Sören (2019)

Regenerative hydrogen, which is produced by renewable electricity used in water electrolyzers, is considered as ideal energy carrier of the future. The selective splitting of seawater into oxygen and hydrogen seem to be a promising alternative compared to established water electrolysis technologies, which typically use highly purified water and electrolytes only. In addition, the back transform...

Pulsed laser deposition of efficient ternary metal oxide photoelectrodes

Kölbach, Moritz (2019)

Climate change, mainly driven by the combustion of fossil fuels releasing the greenhouse gas CO2, is a major threat to humanity and the ecosystems on our planet. To limit global warming, a transition towards a sustainable energy infrastructure based on renewable energies is essential. The storage of solar energy in the form of chemical bonds, in so-called solar fuels, is thereby believed to be ...

In situ studies of Pt nanoparticles on different supports for corrosion stable PEM fuel cell cathodes

Schmies, Henrike (2019)

Wasserstoffbrennstoffzellen bieten als elektrochemische Energiewandler die Möglichkeit, Wasserstoff aus erneuerbaren Resourcen als saubere und emissionsarme Energiequelle für elektrische Verbraucher, wie Elektromotoren, zu nutzen. Um eine konkurrenzfähige Alternative zu heutigen Verbrennungsmotoren in der Automobilindustrie darstellen zu können, müssen aber noch verschiedenste Hindernisse überw...