q&more
My watch list
my.chemie.de  
Login  

News

The role of hydrophobic molecules in catalytic reactions

Optimising electrochemical processes is one of the challenges in developing technologies for renewable energies. New research findings could provide assistance here.

© Elmar Weiler

Water molecules may appear insignificant at first glance, but they have a major influence on chemical reactions. The Franco-German team is investigating what happens at the interface between water and gold.

15-Apr-2021: Electrochemical processes could be used to convert CO2 into useful starting materials for industry. To optimise the processes, chemists are attempting to calculate in detail the energy costs caused by the various reaction partners and steps. Researchers from Ruhr-Universität Bochum (RUB) and Sorbonne Université in Paris have discovered how small hydrophobic molecules, such as CO2, contribute to the energy costs of such reactions by analysing how the molecules interact in water at the interface.

To conduct the work, Dr. Alessandra Serva and Professor Mathieu Salanne from Laboratoire PHENIX at Université Sorbonne collaborated with Professor Martina Havenith and Dr. Simone Pezzotti from the Bochum Chair of Physical Chemistry II.

Crucial role for small hydrophobic molecules

In many electrochemical processes, small hydrophobic molecules react at catalyst surfaces that often consist of precious metals. Such reactions often take place in an aqueous solution, whereby the water molecules form what are known as hydration shells around the other molecules: they accumulate around the other molecules. The water surrounding polar, i.e. hygroscopic molecules behaves differently compared to the water surrounding non-polar molecules, which are also referred to as hydrophobic. The Franco-German research team was interested in this hydrophobic hydration.

Using molecular dynamic simulations, the researchers analysed the hydrophobic hydration of small molecules such as carbon dioxide (CO2) or nitrogen (N2) at the interface between the gold and water. They showed that the interaction of water molecules in the vicinity of small hydrophobic molecules makes a crucial contribution to the energy costs of electrochemical reactions.

Model for calculating energy costs expanded

The researchers implemented these findings in the Lum-Chandler-Weeks theory. This allows the energy required to form water networks to be calculated. “The energy costs for hydrophobic hydration were calculated for the bulk in the previous model. This model has now been expanded here to hydrophobic molecules near interfaces. This case was not included before,” explains Martina Havenith, the Speaker of the Ruhr Explores Solvation Cluster of Excellence, RESOLV for short, at RUB. The adapted model allows the energy costs for hydrophobic hydration to now be calculated at the interface between gold and water based on the size of the hydrophobic molecules. “Due to the water contribution, the size of the molecules plays an important role in the chemical reactions at these interfaces,” says Dr. Simone Pezzotti from the Bochum Chair of Physical Chemistry II.

For instance, the model predicts that small hydrophobic molecules would tend to accumulate at the interface based on the interactions with the water, while larger molecules would remain further away in the solution.

Original publication:
Alessandra Serva, Mathieu Salanne, Martina Havenith, Simone Pezzotti; "Size-dependence of hydrophobic hydration at electrified gold/water interfaces"; PNAS; 2021

Facts, background information, dossiers

More about Ruhr-Universität Bochum

  • News

    A stable copper catalyst for CO2 conversion

    A new catalyst for the conversion of carbon dioxide (CO2) into chemicals or fuels has been developed by researchers at Ruhr-Universität Bochum and the University of Duisburg-Essen. They optimized already available copper catalysts to improve their selectivity and long-term stability. The re ... more

    Quickly identify high-performance multi-element catalysts

    Finding the best material composition among thousands of possibilities is like looking for a needle in a haystack. An international team is combining computer simulations and high-throughput experiments to do this. Catalysts consisting of at least five chemical elements could be the key to ... more

    How bacteria hunt bacteria

    The research team led by Dr. Christine Kaimer from the Microbial Biology department at Ruhr-Universität Bochum (RUB) has taken a close look at predatory bacteria, which feed on other bacteria. Through microscopic examinations and protein analyses, they characterized the strategies used by t ... more

  • q&more articles

    Customized ligands pave the way for new reaction pathways

    For the first time, an efficient catalyst for palladium-catalyzed C–C bonding between aryl chlorides and alkyl lithium compounds has been found. This reaction enables simpler synthesis routes for important products, such as pharmaceuticals, while avoiding much salt waste. more

    Light plus current: The formula for researching what happens to individual nanoparticles

    A combination of dark-field microscopy and electrochemistry can make individual nanoparticles in a liquid medium visible. The technique is suited to determine the activity of catalysts during their use. more

    Vibrational spectroscopy - Label-free imaging

    Spectroscopic methods are now granting us deep insights into biological systems at previously unattainable spatial and temporal resolutions. Complementing the already well-established fluorescence spectroscopy, the major potential of label-free vibrational spectroscopy has become clear in r ... more

  • Authors

    Henning Steinert

    Henning Steinert, born in 1993, studied chemistry at Carl-von-Ossietzky University in Oldenburg, where he researched, among other things, the activation of Si–H bonds on titanium complexes. He is currently working on his doctorate at the Ruhr-Universität Bochum, Chair of Inorganic Chemistry ... more

    Prof. Dr. Viktoria Däschlein-Gessner

    Viktoria Däschlein-Gessner, born in 1982, studied chemistry at Marburg and Würzburg universities and received her doctorate from the Technical University Dortmund in 2009. After a postdoctoral stay at the University of California in Berkeley, she headed an Emmy Noether junior research group ... more

    Kevin Wonner

    Kevin Wonner, born in 1995, studied chemistry with the focus on electrochemical nanoparticle characterization at the Ruhr University Bochum. He started his PhD in 2018 at the chair of Analytical Chemistry II of Professor Dr. Kristina Tschulik and is supported by the graduate school 2376. Hi ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:

 

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE