Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

RUDN chemist tested a new nanocatalyst for obtaining hydrogen

18.10.2018

A chemist from RUDN was the first to use catalysts with ruthenium nanoparticles to obtain hydrogen under the influence of visible light and UV radiation. In the future, such catalysts may be used for large-scale production of hydrogen fuel under the influence of sunlight. The results of the study were published in Applied Catalysis B: Environmental.

Photochemical reactions are one of the most eco-friendly ways of producing "green fuel". They don't consume a lot of energy for heating the raw materials or supporting high pressure levels. To maintain the speed of the reaction one needs only light and photocatalysts.


The chemists monitored the influence of a titanium-dioxide based ruthenium nanocatalyst on the emission of hydrogen from a methanol-water mixture.

Credit: Allen Dressen

Photocatalysts based on platinum, gold, and palladium are highly efficient in such photochemical reactions as hydrogen extraction from biomass derivatives, such as alcohols. However, these metals are expensive, therefore the scientists are in search of cheaper photocatalysts.

Together with their Spanish colleagues, RUDN chemists studied the photocatalytic activity of titanium dioxide enriched with ruthenium particles. It was the first time they were used to obtain hydrogen. The chemists monitored the influence of a titanium-dioxide based ruthenium nanocatalyst on the emission of hydrogen from a methanol-water mixture.

The team studied four catalysts (with 1%, 2%, 3%, and 5% ruthenium content), and each of them was tested in two types of reactions - in the presence of visible light and UV radiation. Before that the systems of titanium dioxide and ruthenium were rarely used, therefore it was important to characterize their composition and optical properties, including quantum efficiency.

It indicates the photosensitivity of a material and is calculated as a ratio of the total number of photons causing the formation of free electrons in a materials and the total number of absorbed photons. This is the main parameter used to compare the photocatalytic activity of substances.

Experiments have shown that the activity of ruthenium-containing photocatalysts under UV radiation is comparable to platinum and palladium analogs. The quantum efficiency of platinum or palladium based compounds calculated on the basis of other studies makes up from 1.9% to 5.1%, and the results of ruthenium photocatalysts stay within this range.

The best value (3.1%) was calculated for the system with 3% ruthenium content. Taking into account the cheapness of ruthenium catalysts, it makes them promising for industrial use. The activity of ruthenium catalysts under visible light was quite low -the quantum efficiency did not exceed 0.6%, but the authors expect it to increase under sunlight up to 1.1%. The scientists have already started verifying this hypothesis.

"Our catalysts based on titanium dioxide and ruthenium appeared to be universal systems and helped us obtain hydrogen in sufficient quantities both under the influence of UV light and visible light,' explains Raphael Luke, director of the Center for Molecular Design and Synthesis of Innovative Compounds for Medicine, and a visiting scholar at RUDN.

"Having modelled the reaction between light and substance and calculated the quantum efficiency of all our samples, we understood that the key role in the catalyst's activity was played by the inter-reaction between ruthenium and titanium dioxide particles, especially by the concentration of ruthenium particles and possibly its compounds with oxygen on the surface of the material. The exact mechanism of this phenomenon is yet to be discovered. We continue our studies and are currently experimenting with obtaining hydrogen under sunlight in Spain and Russia."

###

The team included scientists from the University of Cordoba and the Institute for Catalysis and Petrochemistry (Spain). The work was supported by the 5-100 program.

Media Contact

Valeriya V. Antonova
antonova_vv@rudn.university

http://eng.rudn.ru/ 

Valeriya V. Antonova | EurekAlert!
Further information:
https://www.sciencedirect.com/science/article/pii/S0926337318306544
http://dx.doi.org/10.1016/j.apcatb.2018.07.046

Further reports about: Titanium dioxide photocatalysts photons platinum titanium dioxide visible light

More articles from Life Sciences:

nachricht Key evidence associating hydrophobicity with effective acid catalysis
25.03.2019 | Tokyo Metropolitan University

nachricht Bacteria may travel thousands of miles through the air globally
25.03.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Bacteria may travel thousands of miles through the air globally

25.03.2019 | Life Sciences

Key evidence associating hydrophobicity with effective acid catalysis

25.03.2019 | Life Sciences

Drug diversity in bacteria

25.03.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>