To use all functions of this page, please activate cookies in your browser.
High reaction rates even without precious metals
Precious metals are often efficient catalysts. But they are expensive and rare. However, it has so far been difficult to determine how efficient non-precious metal alternatives are.
Non-precious metal nanoparticles could one day replace expensive catalysts for hydrogen production. However, it is often difficult to determine what reaction rates they can achieve, especially when it comes to oxide particles. This is because the particles must be attached to the electrode using a binder and conductive additives, which distort the results. With the aid of electrochemical analyses of individual particles, researchers have now succeeded in determining the activity and substance conversion of nanocatalysts made from cobalt iron oxide – without any binders. The team led by Professor Kristina Tschulik from Ruhr-Universität Bochum reports together with colleagues from the University of Duisburg-Essen and from Dresden in the Journal of the American Chemical Society, published online on 30 May 2019.
“The development of non-precious metal catalysts plays a decisive role in realising the energy transition as only they are cheap and available in sufficient quantities to produce the required amounts of renewable fuels,” says Kristina Tschulik, a member of the Cluster of Excellence Ruhr Explores Solvation (Resolv). Hydrogen, a promising energy source, can thus be acquired by splitting water into hydrogen and oxygen. The limiting factor here has so far been the partial reaction in which oxygen is produced.
Better than reaction rates currently achieved in industry
How efficiently cobalt iron oxide particles are able to catalyse oxygen generation was investigated by the researchers in the current work. They analysed many individual particles one after the other. The chemists allowed a particle to catalyse oxygen generation on the surface of the electrode and measured the current flow from this, which provides information about the reaction rate. “We have measured current densities of several kiloamps per square metre,” says Tschulik. “This is above the reaction rates currently possible in industry.”
The team showed that, for particles smaller than ten nanometres, the current flow is dependent on the particle size – the smaller the catalyst particle, the smaller the current. The current is also limited by the oxygen that is produced in the reaction and that diffuses away from the particle surface.
Extremely stable despite high stress
Following the catalysis experiments, the chemists observed the catalyst particles under the transmission electron microscope. “Despite the high reaction rates, i.e. although the particles had created so much oxygen, they hardly changed,” summarises Tschulik. “The stability under extreme conditions is exceptional.”
The analysis approach used in the current work can also be transferred to other electrocatalysts. “It is essential to find out more about the activities of nanocatalysts in order to be able to efficiently further develop non-precious metal catalysts for the renewable energy technologies of tomorrow,” says the Bochum-based chemist. In order to analyse the effect of the particle size on the catalytic activity, it is important to synthesise nanoparticles with defined size. As part of the University Alliance Ruhr, the Bochum team cooperates closely with researchers from the University of Duisburg-Essen led by Professor Stephan Schulz, who produce the catalyst particles.
Facts, background information, dossiers
Most read news
- Expanding the reach of therapeutic antibodies
- How the internal compass is constructed in magnetotactic bacteria
- Chemically tailored Graphene
- Hospital germs have their flaws too
- Optimized Binding Cavity
- A Step Ahead in Pharmaceutical Research
- New applications for multicolor OLED microdisplays
- Big results from small solutions
- Graphene sieve turns seawater into drinking water
- Mettler Toledo opens new Competence Center in the Middle-East
News from researchAlle
News from GermanyAlle
- New study on optimizing microbial fuel cells shows electrode material can make all the difference
- Shedding New Light on Viruses
- Natural products against flu viruses
- Antiviral defence regulates intestinal function and overall gut health
- Universal multigene marker may revolutionize biodiversity research
Topics A-ZAll topics
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: