March 2013 – Catalysis Science & Technology Blog

Archive for March, 2013

Catalytic self-cleaning oven glass

28 Mar 2013

Researchers from Belgium have developed a self-cleaning coating for oven windows. Of the available self-cleaning coatings, only a couple are optically transparent at working domestic oven temperatures and these require at least 3 hours of heating. Using manganese and manganese-ceria oxide coatings, the team of researchers discovered that an organic lipid contaminant could be oxidised within one hour to leave transparent, contaminant-free glass.

Read the full article below:

Catalytic self-cleaning coatings for thermal oxidation of organic deposits on glass
Julie E. Verhelst, Daniel Decroupet and Dirk E. De Vos

Catal. Sci. Technol., 2013, DOI: 10.1039/C3CY20874E

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Alkene hydration breaks the rules

22 Mar 2013

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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Adding value to biomass – levulinic acid to gamma-valerolactone

18 Mar 2013

Biomass is the ‘next big thing’ in chemicals production. The goal is to take cheap lignocellulosic feedstocks and convert them into high-value chemicals or even fuels.

A step in this direction has been taken by James Dumesic et al. at the University of Wisconsin-Madison, USA. They wanted to make levulinic acid (LA), a useful precursor to many kinds of industrial chemical including gamma-valerolactone (GVL), a potential green solvent and biofuel, which is also used in the perfume industry. One major problem with converting cellulose to LA is the lack of solubility of both the feedstock and the reaction’s unwanted byproducts.

Dumesic’s team used a solvent system of 90% GVL and 10% water which allowed the cellulose to be converted to fully soluble products, and prevented the precipitation of solid humin byproducts which can make catalyst separation tricky. The polymer Amberlyst 70 proved to be the best catalyst, producing 69% LA from pure cellulose after 16 h. Importantly it also performed well using a ‘real’ biomass feedstock, corn stover. Direct conversion of cellulose to levulinic acid using solid catalyst

After filtration to remove the Amberlyst 70 the LA product was upgraded to GVL by hydrogenation over a ruthenium-tin catalyst, with no need for neutralisation or purification steps. This process simplification could make it a promising approach for the manufacture of added-value chemicals such as GVL from lignocellulosic biomass.

To find out more read the full article in Catalysis Science and Technology:

Direct conversion of cellulose to levulinic acid and gamma-valerolactone using solid acid catalysts
David Martin Alonso, Jean Marcel R. Gallo, Max A. Mellmer, Stephanie G. Wettsteinab and James A. Dumesic
Catal. Sci. Technol., 2013, 3, 927, DOI: 10.1039/c2cy20689g

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Non-canonical amino-acids: An emerging ploy to assist lipases in tackling hostile environments

14 Mar 2013

Posted on behalf of Shreesha Bhat

ncAAs to Lipase:” Here I come comrade, to help you combat hostile environment”

“A friend in need is a friend indeed”. This proverb was justified in an area of chemical research where a group of German scientists devised a new strategy for assisting lipases in hostile environments. Lipases have an important role in organic chemistry as biocatalysts, but have stability issues in organic solvents and other hostile environments making them industrially non-feasible. Among the various approaches used to improve the stability of enzymes, an alternative strategy involving the incorporation of non-canonical amino acids (ncAAs) into the enzymes was adopted by the researchers, which not only resulted in improved stability but also enhanced activity and efficiency.

The subject of study was a lipase obtained from the thermostable bacterium Thermoanaerobacter thermohydrosulfuricus (TTL), from which various ncAAs-containing congeners (mainly analogues of tryptophan, proline, tyrosine, methionine and phenylalanine) were prepared and screened against various organic solvents. They were also evaluated against a set of hostile environments such as metal cations, surfactants, protein reducing, alkylating and denaturing agents, etc. Some congeners conferred stability against pyridine (an important co-solvent for lipase catalyzed polymer synthesis) while some against tert-butanol (solvent for biodiesel production) which is very likely to have a positive influence in the industrial arena.

The present Communication not only demonstrates the potential advantages of using ncAAs in hostile environments but also highlights the challenges that lay ahead in selective biocatalytic transformations.

Find out more about the potential of non-canonical amino acids by reading :

Non-canonical amino acids as a useful synthetic biological tool for lipase-catalysed reactions in hostile environments
Carlos G. Acevedo-Rocha, Michael G. Hoesl, Sebastian Nehring, Marina Royter, Christina Wolschner, Birgit Wiltschi, Garabed Antranikian and Nediljko Budisa
Catal. Sci. Technol., 2013, DOI: 10.1039/C3CY20712A

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Improving conversion efficiency with Ga in solar cells

08 Mar 2013

Shigeru 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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Top ten most accessed articles in January

06 Mar 2013

This month sees the following articles in Catalysis Science & Technology that are in the top ten most accessed:-

Design of hierarchical zeolite catalysts by desilication
Danny Verboekend and Javier Pérez-Ramírez
Catal. Sci. Technol., 2011,1, 879-890 DOI: 10.1039/C1CY00150G

A rational interpretation of improved catalytic performances of additive-impregnated dried CoMo hydrotreating catalysts: a combined theoretical and experimental study
V. Costa , B. Guichard , M. Digne , C. Legens , P. Lecour , K. Marchand , P. Raybaud , E. Krebs and C. Geantet
Catal. Sci. Technol., 2013,3, 140-151 DOI: 10.1039/C2CY20553J

New trends in the synthesis of crystalline microporous materials
Giuseppe Bellussi , Angela Carati , Caterina Rizzo and Roberto Millini
Catal. Sci. Technol., 2013, Advance Article DOI: 10.1039/C2CY20510F

Advances in conversion of hemicellulosic biomass to furfural and upgrading to biofuels
Saikat Dutta , Sudipta De , Basudeb Saha and Md. Imteyaz Alam
Catal. Sci. Technol., 2012,2, 2025-2036 DOI: 10.1039/C2CY20235B

Graphene-based materials for catalysis
Bruno F. Machado and Philippe Serp
Catal. Sci. Technol., 2012,2, 54-75 DOI: 10.1039/C1CY00361E

The role of MoS2 nano-slabs in the protection of solid cracking catalysts for the total conversion of heavy oils to good quality distillates
Giuseppe Bellussi , Giacomo Rispoli , Daniele Molinari , Alberto Landoni , Paolo Pollesel , Nicoletta Panariti , Roberto Millini and Erica Montanari
Catal. Sci. Technol., 2013,3, 176-182 DOI: 10.1039/C2CY20448G

Catalytic activity of unsupported gold nanoparticles
Yusuke Mikami , Amarajothi Dhakshinamoorthy , Mercedes Alvaro and Hermenegildo García
Catal. Sci. Technol., 2013,3, 58-69 DOI: 10.1039/C2CY20068F

Towards environmentally benign catalytic oxidation
Alfons Baiker and Tamas Mallat
Catal. Sci. Technol., 2013,3, 267-267 DOI: 10.1039/C2CY90058K

Mesostructured zeolite Y—high hydrothermal stability and superior FCC catalytic performance
Javier García-Martínez , Marvin Johnson , Julia Valla , Kunhao Li and Jackie Y. Ying
Catal. Sci. Technol., 2012,2, 987-994 DOI: 10.1039/C2CY00309K

Copper N-heterocyclic carbene complexes in catalysis
Jonathan D. Egbert , Catherine S. J. Cazin and Steven P. Nolan
Catal. Sci. Technol., 2013, Advance Article DOI: 10.1039/C2CY20816D

Why not take a look at the articles today and blog your thoughts and comments below.

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Catalysis Science & Technology Blog

Archive for March, 2013

Catalytic self-cleaning oven glass

Alkene hydration breaks the rules

Adding value to biomass – levulinic acid to gamma-valerolactone

Non-canonical amino-acids: An emerging ploy to assist lipases in tackling hostile environments

Improving conversion efficiency with Ga in solar cells

Top ten most accessed articles in January

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