Archive for the ‘News’ Category

Chromium complexes catalyse carbon dioxide/epoxide copolymerization

Homogeneous catalysts for the copolymerisation of carbon dioxide and epoxides encompass a wide range of main group and transition metal complexes; these often incorporate multidentate ligands such as porphyrins, salens, and salans, among other related classes. Amine-bis-phenolates are one class of ligands which have been employed as supporting scaffolds for polymerisation catalysts, providing tunability at the metal centre by functional group modifications at both the aromatic ring positions and on the neutral pendent donor atom. Recent research by the Kozak Group at Memorial University of Newfoundland has focussed on developing amine-bis(phenolate) complexes of mid-to-late transition metals as catalysts for this reaction. In a recent paper published in Catalysis Science & Technology, three six-coordinate chromium complexes with two types of pendent arm were evaluated as copolymerisation catalysts.

The most active catalyst in this study utilised a ligand featuring a coordinated tetrahydrofuranyl pendent group, while ligands featuring non-coordinating benzyl groups resulted in lower yields of the poly(cyclohexene carbonate) product. Although the polymer produced was atactic in all cases, the catalyst was found to be advantageous due to the high percentages of carbonate linkages prevailing in the final product with no evidence suggesting undesirable formation of cyclic carbonate formation.

Read the orginal paper below, which was also cited as a HOT article by the Catalysis Science & Technology referees:

Chromium(III) amine-bis(phenolate) complexes as catalysts for copolymerization of cyclohexene oxide and CO2
Hua Chen, Louise N. Dawe, and Christopher M. Kozak
Catal. Sci. Technol., 2014, Advance Article, DOI: 10.1039/C3CY01002C


Jenna Flogeras

Jenna Flogeras obtained her B.Sc. and M.Sc. in Chemistry from the University of New Brunswick (Fredericton), Canada. She is currently working towards her Ph.D. at Memorial University of Newfoundland, under the supervision of Dr. Francesca Kerton. Her research is focused on the synthesis of biodegradable polymers using main-group metal complexes as catalysts.

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Spinel Cobalt catalysts: Potential solution to reduce tailpipe emissions in LPG

Watching an automobile expert converting a gasoline engine to a LPG engine (using conversion kits) may leave the witness in awe of the technological advances which man has achieved ever since the invention of the wheel. But, this Jugaad comes with its own set of problems and issues which may not leave the environmentalists in the right frame of mind. Pollution has been raising concerns ever since the inception of automobiles (particularly two and three wheelers) and has been a serious concern in both developed as well as developing nations like India and China. To curb the menace of pollution, LPG has been considered an attractive alternative in terms of  low CO2 production, lower emission of other greenhouse gases, cheaper cost and more efficient fuel usage.

However, the use of conversion kits almost kills the purpose of  LPG as it results in emission of high concentrations of light hydrocarbons  (HCs) along with other pollutants such as CO and NOx, as LPG must be run on custom-made engines rather then gasoline engines. The HCs and CO can be oxidized to H2O and CO2 in presence of oxygen, but due to reduced availability of oxygen in LPG engines, the demand of oxidation catalysts has risen in order to facilitate the conversion of HCs into CO2 and H2O. Three-way catalysts (TWC) which include the platinum group metals, fail to oxidize HCs at low temperatures (between 200 to 300 °C), resulting in the maximum emissions of HCs after a cold-start. (Engines started when they are cold generally have initial temperatures around this range)

To come up with a low-temperature catalyst, researchers from Indian Institute of  Technology (IIT-BHU) tried their hands with cobaltite spinel oxidation catalysts (MCo2O4) and had immediate success with their experiments. They studied different metal cobaltites (M = Zn, Ni, Cu) and found Ni cobaltite to exhibit the best performance for oxidation of LPG at low temperatures, with the effectiveness of the catalysts following the order: NiCo2O4 > CuCo2O4 > ZnCo2O4.

Due to the synergistic effect of simultaneous oxidation of LPG and CO, total LPG oxidation was found to occur at 185 °C, which is 10°C less than that for oxidation of LPG alone. Thus, the researchers were able to devise a new spinel catalyst which catalyse the oxidation of HCs and CO at low temperatures and were able to solve the problem of  cold-start of LPG fuelled vehicles to some extent.

Low Temperature Complete Combustion of Lean Mixture of LPG Emissions over Cobaltite Catalysts

Read more about the preparation and characterization of spinel cobaltite catalysts from the article:

Low Temperature Complete Combustion of Lean Mixture of LPG Emissions over Cobaltite Catalysts
Ram Prasad, Sony Chaddha and Pratichi Singh
Catal. Sci. Technol., 2013, Accepted Manuscript
DOI: 10.1039/C3CY00537B


Shreesha Bhat, Web Writer Shreesha Bhat is a M.S.(Pharm.) in Medicinal Chemistry from National Institute  of  Pharmaceutical  Education and Research,  India. His area of interests  include chemical  synthesis of biologically important  molecules  and developing  newer methods for organic  synthesis using novel catalysts.

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Homogeneous catalyst made to act more like an enzyme

Homogeneous catalytic systems which display selectivity in a mixture of similar substrates are rare. Now scientists in Italy and the Netherlands have shown that encapsulating a homogeneous catalyst in a supramolecular host can give it a more discerning nature.

 Alessandro Scarso at the University of Venice and colleagues found that putting a catalyst within a supramolecular host makes it act more like an enzyme – only specific substrates can fit into the cavity and reach the catalyst. Supramolecular interactions between the substrate, host and catalyst provide additional levels of electronic restriction.

Read the full story at Chemistry World

Substrate Selectivity in the Alkyne Hydration Mediated by NHC-Au(I) controlled by Encapsulation of the Catalyst within a Hydrogen Bonded Hexameric Host

Substrate Selectivity in the Alkyne Hydration Mediated by NHC-Au(I) controlled by Encapsulation of the Catalyst within a Hydrogen Bonded Hexameric Host
Alessandro Scarso, Alessandra Cavarzan, Francesco Trentin, Joost Reek and Giorgio Strukul
Catal. Sci. Technol., 2013, DOI: 10.1039/C3CY00300K, Communication

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Top ten most accessed articles from April – June 2013

During the months April – June, the following articles are in the Top Ten most accessed:-

Metal sulphide semiconductors for photocatalytic hydrogen production 
Kai Zhang and Liejin Guo 
Catal. Sci. Technol., 2013,3, 1672-1690 
DOI: 10.1039/C3CY00018D     

A review of controllable synthesis and enhancement of performances of bismuth tungstate visible-light-driven photocatalysts 
Liwu Zhang and Yongfa Zhu 
Catal. Sci. Technol., 2012,2, 694-706 
DOI: 10.1039/C2CY00411A     

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

New trends in the synthesis of crystalline microporous materials 
Danny Verboekend and Javier Pérez-Ramírez 
Catal. Sci. Technol., 2011,1, 879-890 
DOI: 10.1039/C1CY00150G     

CuFe, CuCo and CuNi nanoparticles as catalysts for higher alcohol synthesis from syngas: a comparative study 
Kang Xiao, Xingzhen Qi, Zhenghong Bao, Xinxing Wang, Liangshu Zhong, Kegong Fang, Minggui Lin and Yuhan Sun   
Catal. Sci. Technol., 2013,3, 1591-1602 
DOI: 10.1039/C3CY00063J    

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

Copper N-heterocyclic carbene complexes in catalysis 
Jonathan D. Egbert, Catherine S. J. Cazin and Steven P. Nolan   
Catal. Sci. Technol., 2013,3, 912-926 
DOI: 10.1039/C2CY20816D     

High CO2 and CO conversion to hydrocarbons using bridged Fe nanoparticles on carbon nanotubes 
Justin P. O’Byrne, Rhodri E. Owen, Daniel R. Minett, Sofia I. Pascu, Pawel K. Plucinski, Matthew D. Jones and Davide Mattia 
Catal. Sci. Technol., 2013,3, 1202-1207 
DOI: 10.1039/C3CY20854K    

Challenge and progress: palladium-catalyzed sp3 C–H activation 
Hu Li, Bi-Jie Li and Zhang-Jie Shi  
Catal. Sci. Technol., 2011,1, 191-206 
DOI: 10.1039/C0CY00076K     

Noble metal-free Ni(OH)2–g-C3N4 composite photocatalyst with enhanced visible-light photocatalytic H2-production activity 
Jiaguo Yu, Shuhan Wang, Bei Cheng, Zhang Lin and Feng Huang 
Catal. Sci. Technol., 2013,3, 1782-1789 
DOI: 10.1039/C3CY20878H     

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

Fancy submitting an article to Catalysis Science & Technology? Then why not submit to us today or alternatively email us your suggestions.

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Top ten most accessed articles in March

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

Nickel nanoparticles catalyse reversible hydration of carbon dioxide for mineralization carbon capture and storage 
Gaurav A. Bhaduri and Lidija Šiller   
Catal. Sci. Technol., 2013,3, 1234-1239 
DOI: 10.1039/C3CY20791A  

A review of controllable synthesis and enhancement of performances of bismuth tungstate visible-light-driven photocatalysts 
Liwu Zhang and Yongfa Zhu  
Catal. Sci. Technol., 2012,2, 694-706 
DOI: 10.1039/C2CY00411A  

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

New trends in the synthesis of crystalline microporous materials 
Giuseppe Bellussi, Angela Carati, Caterina Rizzo and Roberto Millini  
Catal. Sci. Technol., 2013,3, 833-857 
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 Alama   
Catal. Sci. Technol., 2012,2, 2025-2036 
DOI: 10.1039/C2CY20235B  

High CO2 and CO conversion to hydrocarbons using bridged Fe nanoparticles on carbon nanotubes 
Justin P. O’Byrne, Rhodri E. Owen, Daniel R. Minett, Sofia I. Pascu, Pawel K. Plucinski, Matthew D. Jones and Davide Mattia  
Catal. Sci. Technol., 2013,3, 1202-1207 
DOI: 10.1039/C3CY20854K  

Direct C–H bond arylations and alkenylations with phenol-derived fluorine-free electrophiles 
Sergei I. Kozhushkov, Harish Kumar Potukuchi and Lutz Ackermann  
Catal. Sci. Technol., 2013,3, 562-571 
DOI: 10.1039/C2CY20505J  

Copper N-heterocyclic carbene complexes in catalysis 
Jonathan D. Egbert, Catherine S. J. Cazin and Steven P. Nolan  
Catal. Sci. Technol., 2013,3, 912-926 
DOI: 10.1039/C2CY20816D  

Diesel fuel from biomass 
Carlo Perego and Marco Ricci   
Catal. Sci. Technol., 2012,2, 1776-1786 
DOI: 10.1039/C2CY20326J  

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

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

Fancy submitting an article to Catalysis Science & Technology? Then why not submit to us today or alternatively email us your suggestions.

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Tannins help in biphasic catalysis

There are pros and cons to both homogeneous and heterogeneous catalytic strategies. One way to get the best of both worlds is to use aqueous-organic biphasic catalysis. This approach hasn’t been widely utilised so far due to interfacial resistance between the phases which causes a low catalytic activity.

Researchers in China have overcome this by using tannins from Black Wattle (an acacia tree species). The tannins “amphiphilicly” stabilise catalytic palladium nanoparticles enabling them to catalyse reactions in the organic phase whilst remaining in the aqueous phase for subsequent re-use, without loss of activity.

Read the full article here:

Using plant tannin as natural amphiphilic stabilizer to construct aqueous-organic biphasic system for highly active and selective hydrogenation of quinoline
Hui Mao, Jun Ma, Yang Liao, Shilin Zhao and Xuepin Liao
Catal. Sci. Technol., 2013, DOI:10.1039/C3CY00108C

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Catalytic self-cleaning oven glass

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.

self-cleaning oven 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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Capturing the potential of carbon dioxide

Carbon dioxide is a problem. As a greenhouse gas it contributes towards global warming, and its ever-growing concentrations in the atmosphere are cited as a cause of anthropomorphic climate change. But now a team of researchers from the University of Bath have opened up the idea of using carbon dioxide as a useful potential feedstock; a useful chemical resource rather than a troublesome waste product.

Davide Mattia, who leads the research team, has taken inspiration from the well-known Fischer-Tropsh process, which uses an iron catalyst to react hydrogen with carbon monoxide, producing a mixture of alkanes that can be used as fuel. Mattia’s catalyst, which works with both carbon monoxide and carbon dioxide, is also iron based, taking the form of iron nanoparticles embedded on carbon nanotubes. It has a rather unique method of preparation, which is not only simpler to carry out, but results in a more effective catalyst.

To read the full story, story please visit Chemistry World.

High CO2 and CO conversion to hydrocarbons using bridged Fe nanoparticles on carbon nanotubes
Justin P. O’Byrne, Rhodri E. Owen, Daniel R. Minett, Sofia I. Pascu, Pawel K. Plucinski, Matthew D. Jones and Davide Mattia
Catal. Sci. Technol., 2013, Advance Article
DOI: 10.1039/C3CY20854K

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Noble metal brings activity to tin oxide

Posted on behalf of Sara Coles, Web-writer

James Wiswall and his colleagues, working with Professor Margaret Wooldridge at the University of Michigan, USA, have been studying catalytic propane combustion. This reaction has important implications for areas such as power generation (for example, integration of catalysts directly into the internal combustion engine combustion chamber) and removal of volatile organic compounds (VOCs) from emissions.

The group used a stagnation-point flow reactor to study the catalytic activity of platinum, palladium, tin dioxide and 90 wt% SnO2–10 wt% Pt for the combustion of propane under a variety of reaction conditions. Preliminary results suggest that the 90 wt% SnO2–10 wt% Pt catalyst provides significant activity and has similar trends in activity as a function of stagnation-plane temperature to those of Pt and Pd, whereas pure SnO2 shows no activity.

The researchers are optimistic that even better activity could be obtained if optimisation studies are carried out.

This development shows potential for Pt/SnO2 to be used as a fuel oxidation catalyst. For more detail, read the full article:

An experimental investigation of catalytic oxidation of propane using temperature controlled Pt, Pd, SnO2, and 90% SnO2–10% Pt catalysts
J. T. Wiswall, M. S. Wooldridge and H. G. Im
Catal. Sci. Technol., 2013, 3, 618–625

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Industrial-scale enzyme catalysis a step closer

Many biocatalysts require expensive co-factors when they are used in the production of industrially relevant compounds, but a team of UK chemists has replaced one such co-factor – nicotinamide adenine dinucleotide phosphate (NADPH) – with a smaller, more practical molecule: methyl viologen.

The production of cyclohexanone has been successfully catalysed using this method, combining methyl viologen with a biocatalyst enzyme in an electrochemical microfluidic set-up.

The work, published in Catalysis Science & Technology, represents the first time such enzyme-catalysed chemistry has been carried out without a co-factor, and presents a practical and economic route to its use in large-scale synthesis.

Read the article…

Electro-enzymatic viologen-mediated substrate reduction using pentaerythritol tetranitrate reductase and a parallel, segmented fluid flow system
Karl Fisher, Stephan Mohr, David Mansell, Nicholas J. Goddard, Peter R. Fielden and Nigel S. Scrutton

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