30 Oct 2014
Written by Christopher Hinde. Christopher obtained his Masters in Chemistry (MChem) from the University of Southampton, UK in 2011. He is currently doing research towards a Ph.D. in the area of materials chemistry and catalysis under the supervision of both Dr Robert Raja at the University of Southampton and Prof. T. S. Andy Hor at the Institute of Materials Research and Engineering (IMRE), a research institute in Singapore’s Agency for Science Technology and Research (A*STAR).
In this recent communication, W. Zhang and co-workers have demonstrated a novel way to form covalent porphyrinic frameworks (CPFs) using squaraine and hydrazine linkers. By using purely organic moieties the researchers have eliminated the need for metal nodes that are present in the more traditional porous coordination polymers.
Using the principles of supramolecular chemistry the authors have used a metallation process to introduce manganese, a well-known and abundant redox active transition metal, into the cavity of the porphyrin component of the framework. Thus, an easily accessible active site for redox catalysis was generated and subsequently demonstrated to be active for the selective oxidation of aliphatic molecules.
Interestingly, it was also shown that the choice of linker can have an effect on the resulting catalytic activity of these new materials. Preliminary characterisation showed a correlation between the extended conjugation of the organic framework, the state of the manganese and the activity/selectivity of the catalytic processes. This phenomenon, often observed in homogeneous porphyrin catalysts, has been elegantly incorporated into these heterogeneous analogues. One can hypothesise that in future, by careful design of the organic linkers joining the porphyrin units, it may be possible to fine-tune the material for different catalytic reactions.
To find out more, why not take a look at the article now?
Bottom-up approach to engineer two covalent porphyrinic frameworks as effective catalysts for selective oxidation
Weijie Zhang, Pingping Jiang, Ying Wang, Jian Zhang and Pingbo Zhang
Catal. Sci. Technol., 2015, DOI: 10.1039/C4CY00969J
01 Oct 2014
D. Fogg et al. have discovered a powerful means to observe the behaviour of Grubbs metathesis catalysts.
The University of Ottawa researchers tagged first- and second-generation ruthenium catalysts with a 13C label at the alkylidene site using straightforward synthesis routes. This isotopic enrichment allowed 13C NMR spectroscopy to serve as a sensitive probe for the amine-initiated decomposition pathway.
A surprising preference for nucleophilic attack by phosphine was clearly revealed in the 13C NMR spectrum. This demonstrates the diagnostic utility of 13C-enriched complexes relative to both their unlabelled and deuterium-labelled analogues.
This article is featured amongst many other excellent contributions in the latest Catalysis Science & Technology themed issue, Mechanistic Studies in Catalysis.
Take a look at the original article online now!
Isotopic Probes for Ruthenium-Catalyzed Olefin Metathesis
Justin A. M. Lummiss, Adrian G. G. Botti, and Deryn E. Fogg*
Catal. Sci. Technol. 2014, Advance Article, DOI: 10.1039/C4CY01118J
Jenna Flogeras obtained her B.Sc. and M.Sc. in Chemistry from the University of New Brunswick (Fredericton), Canada. She is currently a Ph.D. student at Memorial University in Newfoundland, where she studies aluminum-based catalysts under the supervision of Dr. Francesca Kerton.
18 Sep 2014
We are delighted to present a themed issue on ‘Mechanistic studies in catalysis’, which encompasses novel and diverse research in both homogeneous and heterogeneous catalysis. The guest editors for this themed issue are Professors John Brown (University of Oxford), Andreas Pfaltz (University of Basel), and Rutger van Santen (Eindhoven University of Technology).
Here’s a few highlights from the issue:
- Perspective: Distinguishing homogeneous from nanoparticle asymmetric iron catalysis, Jessica F. Sonnenburg and Robert H. Morris, DOI: 10.1039/c4cy00468j
- Perspective: Differential selectivity measurements and competitive reaction methods as effective means for mechanistic studies of complex catalytic reactions, Alexander F. Schmidt, Anna A. Kurokhtina and Elizaveta V. Larina, DOI: 10.1039/c4cy00479E
- Minireview: Rhodium diphosphine complexes: a case study for catalyst activation and deactivation, Antje Meißner, Elisabetta Alberico, Hans-Joachim Drexler, Wolfgang Baumann and Detlef Heller, DOI: 10.1039/c4cy00497C
Many more great contributions have been received, so make sure to have a look at the rest of the themed collection online now!
15 Sep 2014
A team of researchers at the University of Kentucky have developed highly active homogeneous catalysts for the capture of carbon dioxide in post-combustion processes. The complexes, based on zinc and cobalt metal centres, increase mass transfer by up to 34% in concentrated, aqueous solutions of primary amine.
Carbonic anhydrase metalloenzymes are known as the most active catalysts for the hydration of carbon dioxide under mild conditions. The catalysts reported here are inexpensive alternatives that can better tolerate the harsh conditions of industrial gas streams.
Read the full article online now:
K. Liu et al., Catal. Sci. Technol. 2014, Advance Article
ras obtained her B.Sc. and M.Sc. in Chemistry from the University of New Brunswick (Fredericton), Canada. She is currently a Ph.D. student at Memorial University in Newfoundland, where she studies aluminum-based catalysts under the supervision of Dr. Francesca Kerton.
23 Jul 2014
The latest issue of Catalysis Science and Technology contains a themed collection on Sustainable catalytic conversions of renewable substrates. The issue was guest edited by Pieter C. A. Bruijnincx (Utrecht University) and Yuriy Román-Leshkov (Massachusetts Institute of Technology).
This issue contains contributions on topics related to catalytic biomass conversion methods, including homogeneous, heterogeneous and enzymatic processes. The themed issue will cover contributions concerned with chemical or chemical engineering aspects of the selective catalytic conversion of renewable feedstocks, for instance lignocellulosic biomass or its (hemi)cellulose or lignin components, or with the catalytic conversion of renewable platform molecules that can be derived from these feedstocks.
Here’s a small taster of the excellent content in this themed issue:
- Perspective: Transition metal-catalyzed oxidative double bond cleavage of simple and bio-derived alkenes and unsaturated fatty acids,
Peter Spannring, Pieter C. A. Bruijnincx, Bert. M. Weckhuysen and Robertus J. M. Klein Gebbink , DOI: 10.1039/C3CY01095C
- Perspective: A review of advanced catalyst development for Fischer–Tropsch synthesis of hydrocarbons from biomass derived syn-gas,
Hessam Jahangiri, James Bennett, Parvin Mahjoubi, Karen Wilson and Sai Gu, DOI: 10.1039/C4CY00327F
- Communication: Catalytic hydrosilylation of oxalic acid: chemoselective formation of functionalized C2-products,
Elias Feghali, Olivier Jacquet, Pierre Thuéry and Thibault Cantat, DOI: 10.1039/C4CY00339J
Check out the rest of the articles in this exciting and timely themed issue on the website now!
08 Jul 2014
Congratulations to the poster prize winners at NSC2014 (16th Nordic Symposium on Catalysis). Green Chemistry and Catalysis Science & Technology were pleased to sponsor a poster prize each at the symposium, which were awarded as follows:
Green Chemistry poster prize
awarded to Aron Dombovari, University of Oulu
for “Photocatalytic processing of algae”
Catalysis Science & Technology poster prize
awarded to Jacob O. Abildstrøm, Technical University of Denmark
for “Investigation of Mesoporous TS-1 for the Catalytic Formation of N-oxides”
The prize winners received a certificate and a book from Royal Society of Chemistry Books.
You can read more about the Poster Award and find out about the Nordic Symposium on the UiO website.
02 Jun 2014
Due to its sustainability appeal, carbon dioxide is gaining popularity as a feedstock for the synthesis of commercially-important chemicals, including fuels for energy applications. Methanol may be formed from carbon dioxide via water splitting with the assistance of photocatalysts. In this study, reverse photofuel cells incorporating tungsten oxide and layered double hydroxide (LDH) photocatalysts were used for the oxidation of water and the reduction of carbon dioxide, respectively. Two different fabrication designs were tested: in one cell, the catalysts were either used alone or mixed with carbon black; in the other, LDH was mounted on copper, tungsten oxide was mounted on carbon, and the photoelectrodes were immersed in hydrochloric acid solution.
The second cell outperformed the first in terms of the amount of photocurrent generated, since the transfer of protons across the Nafion film was more efficient in the acid solution. However, product selectivity differed between the two cells: gaseous carbon dioxide led to the preferential formation of methanol, whereas the second cell predominantly generated hydrogen due to the poor solubility of carbon dioxide in water.
The full paper is available here:
Photocatalytic conversion of carbon dioxide into methanol in reverse fuel cells with tungsten oxide and layered double hydroxide photocatalysts for solar fuel generation
Motoharu Morikawa, Yuta Ogura, Naveed Ahmed, Shogo Kawamura, Gaku Mikami, Seiji Okamoto, and Yasuo Izumi
Catal. Sci. Technol., 2014, Advance Article, DOI: 10.1039/C3CY00959A
Jenna Flogeras obtained her B.Sc. and M.Sc. in Chemistry from the University of New Brunswick (Fredericton), Canada. Currently a Ph.D. student at Memorial University of Newfoundland, she is excited to spend some time outside the laboratory this summer to explore Thailand and Southeast Asia.