Archive for the ‘Photocatalysis’ Category

Cleaner diesel engines – not just a pipe dream!

Selective catalytic reduction (SCR) to date presents the most promising deNOx technology for diesel engines.  Removal of NOx from diesel exhaust is problematic due to the wide temperature range (373–923 K) at which diesel engines operate.  This is due to inefficient conversion at low temperature (below 423 K) with the commonly used ionic exchanged zeolites or low selectivity to N2 with supported MnOx catalysts.

In this HOT article, Tanaka et al. found that the temperature had a significant effect on the photocatalytic reactions in the gas phase over a TiO2 photocatalyst with a maximum conversion of 84% (at GHSV 100,000 h-1 and 433 K).  The amount of NH3 at high temperature was found to be key to a high NO conversion.  The results provide evidence of the potential practicality of the use of photo-SCR for diesel engines.

Effects of reaction temperature on photocatalytic activity

Effects of reaction temperature on photocatalytic activity

Read more about these developments in photocatalysis by downloading the article now:

Effects of reaction temperature on the photocatalytic activity of photo-SCR of NO with NH3 over a TiO2 photocatalyst
Akira Yamamoto, Yuto Mizuno, Kentaro Teramura, Tetsuya Shishido and Tsunehiro Tanaka
Catal. Sci. Technol., 2013, Advance Article
DOI: 10.1039/C3CY00022B

This article is part of a themed issue on photocatalysis that is due to be published later this year.

You may also be interested in a perspective recently published by the same author on the subject:

A unique photo-activation mechanism by “in situ doping” for photo-assisted selective NO reduction with ammonia over TiO2 and photooxidation of alcohols over Nb2O5
Tetsuya Shishido, Kentaro Teramura and Tsunehiro Tanaka
Catal. Sci. Technol., 2011, 1, 541-551
DOI: 10.1039/C1CY00104C, Perspective

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Improving photocatalytic properties of titanium oxide with a new doping method

TiO2 nanotubes demonstrate photocatalytic properties that make them useful in applications such as decomposition of organic pollutants. These nanotubes are commonly grown in an anodization process that takes place in an electrolytic bath, with dopants, which are used to modify the catalytic properties of the nanotubes, added at a later stage.

In this paper, Hahn and co-workers have demonstrated a new growth method in which the desired dopants are dissolved in the electrolyte solution. The nanotubes grown from this solution incorporate the dopants, and no further treatment is required. A test of the photocatalytic properties of the nanotubes also confirms that it behaves very similar to nanotubes grown by conventional methods. This fast and convenient way of manufacturing doped TiO2 nanotubes opens the route to many potential future applications.

 Photocatalytic properties of in situ doped TiO2-nanotubes grown by rapid breakdown anodization

Find out more by reading the full article:

Photocatalytic properties of in situ doped TiO2-nanotubes grown by rapid breakdown anodization
Robert Hahn, Martin Stark, Manuela Sonja Killian and Patrik Schmuki
Catal. Sci. Technol., 2013, Advance Article
DOI: 10.1039/C3CY00021D

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Alkene hydration breaks the rules

Alkene hydration (the addition of water to a carbon double bond) is an important industrial process for the direct synthesis of alcohols, widely used as chemical intermediates for resins, agricultural chemicals, surfactants, etc.  In an extension of their previous work which involved selective aromatic ring hydroxylation by water with a platinum-loaded titanium oxide photocatalyst, the Yoshida Group, applied this photocatalytic system to alkene hydration. 

Hydration of alkenes followed the anti-Markovnikov rule

The Pt–TiO2 photocatalyst efficiently promoted anti-Markovnikov hydration of various alkenes with high selectivity.  A possible reaction mechanism is also discussed in detail based on experiment and molecular orbital calculations.  The results should prove useful for designing novel photocatalysts for selective organic transformations.

Read more about these developments in photocatalytic research by downloading the full article now:

Anti-Markovnikov hydration of alkenes over platinum-loaded titanium oxide photocatalyst
Hayato Yuzawa, Shoko Yoneyama, Akihito Yamamoto, Masanori Aoki, Kazuko Otake, Hideaki Itoh and Hisao Yoshida
Catal. Sci. Technol., 2013, DOI: 10.1039/C3CY00019B

This article is part of a themed issue on photocatalysis that is due to be published later this year.

Also, check out the previous paper which sparked this research:

Photocatalytic hydroxylation of aromatic ring by using water as an oxidant
Hisao Yoshida, Hayato Yuzawa, Masanori Aoki, Kazuko Otake, Hideaki Itoh and Tadashi Hattori
Chem. Commun., 2008, 4634-4636
DOI: 10.1039/B811555A

And the latest work by this group:

Heterogeneous palladium catalyst hybridised with titanium oxide photocatalyst for direct C–C bond formation between aromatic ring and acetonitrile
Hisao Yoshida, Yuki Fujimura, Hayato Yuzawa, Jun Kumagai and Tomoko Yoshida
Chem. Commun., 2013, Accepted Manuscript
DOI: 10.1039/C3CC41068D

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Improving conversion efficiency with Ga in solar cells

Adding Ga to CuInS2-based solar cells can improve conversion efficiencyShigeru Ikeda and colleagues from Osaka University, Japan, have evidenced the ease and effectiveness of using spray pyrolysis to make CuInS2-based solar cells in this HOT Catalysis Science & Technology paper.  The effect of Ga-doping on structural properties related to photovoltaic and photoelectrochemical properties were investigated.  Download the manuscript today to find out more…

Fabrication of CuInS2 and Cu(In,Ga)S2 thin films by a facile spray pyrolysis and their photovoltaic and photoelectrochemical properties
Shigeru Ikeda,  Midori Nonogaki,  Wilman Septina,  Gunawan Gunawan,  Takashi Harada and Michio Matsumura
Catal. Sci. Technol., 2013
DOI: 10.1039/C3CY00020F

This article is part of a themed issue on photocatalysis that is due to be published later this year.

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Submissions open for Photocatalysis themed issue

Submissions are now open for Catalysis Science & Technology‘s upcoming themed issue on photocatalysis.

The themed issue, guest edited by Professors Kazunari Domen and Licheng Sun, will focus on both homogeneous and heterogeneous photocatalysis research, providing insight into the fundamentals as well as the applicational development of photocatalytic reactions.

Manuscript deadline: 7th January 2013

See our author guidelines, for information on article types. Please note that all manuscripts will undergo the usual standard of peer-review.

SUBMIT your manuscript now.
For any queries, please contact the Editorial Office.

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Incredible ionic liquids: an article collection

Ionic liquids are pretty self explanatory; they are ionic materials in a liquid state. In a ‘normal’ liquid, interactions are usually governed by Van de Waals or H-bonding forces. In ionic liquids it is ionic bonding interactions which dominate, meaning ionic liquids possess some interesting and unique properties.

The field of ionic liquids grew after Paul Walden’s observations of ethylammonium nitrate in 1914,1 since then the study and use of ionic liquids has grown phenomenally, with applications in analytics, biology, electrochemistry, physical chemistry, engineering, solvents and catalysis.

The academic and industrial interest in ionic liquids has thrown up some remarkable discoveries, particularly in recent years, so to keep you up to date with latest break-through research in the field we have collected these high quality articles which are free to access!*

Click here for the full list of free articles

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Reviews in Catalysis

Are you new to the field of catalysis and searching for a good starting point in the literature?
Are you an experienced researcher on the hunt for a comprehensive overview on recent advances in catalysis?

Then look no further.

Over the past year we have published a number of Perspectives and Mini Reviews authored by world-leading scientists and covering all areas of catalysis.  

Scroll down to begin browsing our reviews in:

Asymmetric organocatalysis
Metal-mediated asymmetric catalysis
Fuel synthesis
Nanocatalysis
Biomimetic and biocatalysis
Zeolitic catalysis
Photocatalysis

(more…)

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Shining light on the Hantzsch reaction

Scientists from the Indian Institute of Technology have investigated the effect of visible light on the Hantzsch reaction – a method by which to produce dihydropyridines which have found merit for cardiovascular disease treatment. By doing so, they were able to develop a photocatalytic-based methodology for producing 2-arylpyridines. Whilst such compounds are popular in medicinal chemistry and supramolecular coordination chemistry fields, their synthesis can be troublesome.

Armed with a catalytic amount of [Ru(bpy)3]2+ and a household compact fluorescent lamp, the team synthesised the 2-arylpyridine compound through photocatalytic oxidation of the 1,2-dihydropyridine Hantzsch product.

For further details on the reaction conditions and mechanism, read the the Full Paper:
[Ru(bpy)3]2+ Aided Photocatalytic Synthesis of 2-Arylpyridines via Hantzsch Reaction under the Visible Irradiation and Oxygen Atmosphere
Rajakumar Ananthakrishnan and Sarifuddin Gazi

Make sure that you’re signed up to the Catalysis Science & Technology e-alerts to keep up-to-date with the latest journal content.

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