Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018

Researchers at Tokyo Institute of Technology have developed a ruthenium-based perovskite catalyst[1] that shows strong activity even at low temperatures (down to 313 K). The reusable catalyst does not require additives, meaning that it can prevent the formation of toxic by-products. The oxidation of sulfides is a commercially important process with broad applications ranging from chemicals production to environmental management.

A research group led by Keigo Kamata and Michikazu Hara of Tokyo Institute of Technology (Tokyo Tech) has succeeded in developing a barium ruthenate (BaRuO3) perovskite -- the first catalyst of its kind shown to be capable of the selective oxidation of sulfides under mild conditions, with molecular oxygen (O2) as the only oxidant and without the need for additives.


Top: Schematic representations of the face-sharing unit in rhombohedral BaRuO3 and corner-sharing unit in tetragonal RuO2, cubic SrRuO3, and orthorhombic CaRuO3. Bottom: Scanning electron microscope (SEM) image of BaRuO3.

Credit: Keigo Kamata

Reporting their findings in ACS Applied Materials & Interfaces, the researchers state that BaRuO3 has three advantages over conventional catalysts.

Firstly, it exhibits high performance even at 313 K, a temperature much lower than the 373-423 K range reported in previous systems including other ruthenium- and manganese-based catalysts. Secondly, its high rate of oxygen transfer indicates that it has many potential uses; for example, it is applicable to the oxidative desulfurization[2] of dibenzothiophene, which can produce a 99% yield of pure sulfone. Thirdly, the new catalyst is recyclable -- the present study showed that BaRuO3 could be reused at least three times without loss of performance.

The achievement overcomes several classic limitations, such as the need for additives, toxic reagents and high reaction temperatures to achieve good catalytic performance.

The catalyst has a rhombohedral structure (see Figure 1). While other ruthenium-based catalysts investigated to date such as SrRuO3, CaRuO3 and RuO2 can all be described as having corner-sharing octahedral units, BaRuO3 has face-sharing octahedra. This configuration is thought to be one of the main reasons behind the catalyst's higher oxygen transfer capability.

The way in which BaRuO3 was synthesized -- based on the sol-gel method[3] using malic acid -- was also important. The researchers say: "The catalytic activity and specific surface area of BaRuO3 synthesized by the malic acid-aided method were higher than those of BaRuO3 synthesized by the polymerized complex method."

The study highlights the importance of subtle changes in the nanoscale structure of perovskite catalysts, and could provide promising leads for further research on a wide range of perovskite-based functional materials.

###

Technical terms

[1] Perovskite catalyst: Referring to a family of catalysts with the general formula ABO3, which are of great interest due to their structural simplicity, flexibility, good stability and controllable physicochemical properties.

[2] Oxidative desulfurization: An important reaction process for sulfur removal -- this is particularly relevant to the fuel industry and efforts to curb sulfur emissions.

[3] Sol-gel method: A process widely used to prepare novel materials by converting monomers in a colloidal solution (sol) to a network of polymers (gel).

Related Links

A ruthenium-based catalyst with highly active, flat surfaces outperforms metal-based competitors

Reusable ruthenium-based catalyst could be a game-changer for the biomass industry

Emiko Kawaguchi | EurekAlert!
Further information:
http://dx.doi.org/10.1021/acsami.8b05343

More articles from Life Sciences:

nachricht Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University

nachricht Bacteria bide their time when antibiotics attack
22.03.2019 | Rice 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

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>