PCCP Blog

This paper from the group of Matthias Arenz at the Nano-Science Center at the University of Copenhagen may prove crucial for comparing catalysts and catalyst matrices for low temperature fuel cells.

In “Pt based PEMFC catalysts prepared from colloidal particle suspensions – a toolbox for model studies” Speder and co-workers demonstrate the applicability of their approach to catalyst fabrication in a model study. The key result is that their catalyst synthesis allow for accurate comparison of different catalyst systems as their procedures are reproducible and yield consistent results.

Fuel cell catalysts on solid supports have been difficult to compare, as the means of their preparation introduce differences, often larger than those variations resulting from the parameter under study. The work summarized in this paper opens a way around this issue, making comparative study feasible. Of this reason alone you should have a look at the paper. On top of that you get the interesting result regarding the anchoring of Pt catalyst particles to the carbon support.

by Dr Thomas Just Sørensen

Read the full details of this HOT PCCP article today:

Pt based PEMFC catalysts prepared from colloidal particle suspensions – a toolbox for model studies
Jozsef Speder, Lena Altmann, Melanie Roefzaad, Marcus Bäumer, Jacob J. K. Kirkensgaard, Kell Mortensen and Matthias Arenz
DOI: 10.1039/C3CP50195G

Japanese scientists have carefully tailored the anion and cation to create of  a new class of ILs which are both strongly hydrophobic and can also hydrogen bond effectively.

The authors found that tetra-n-octylphosphonium paired with ethylphosphonate or n-butylphosphonate were able to form a stable seperate phase after mixing with water while also showing hydrogen bonding characteristics.

This family of ILs could potentially  be used in environmentally friendly separation processes.

Read this exciting PCCP article in full:

Hydrophobic and polar ionic liquids
Yukinobu Fukaya and Hiroyuki Ohno
DOI: 10.1039/C3CP44214D

If you liked this you may also enjoy our recent PCCP themed issue on Interfaces of Ionic Liquids Guest Edited by Professor Frank Endres.

Surface-enhanced Raman spectroscopy (SERS) is a variation of Raman spectroscopy whereby the molecule of interest is first adsorbed onto a surface, often of silver or gold, rather than being studied in solution. The defining advantage of this approach is that the observed intensity of the spectrum is much greater than in solution studies. This effect is strongly associated with the use of nanoscale surfaces for adsorption.

It is clear from reading the article ‘Persistent misconceptions regarding SERS’ by Martin Moskovits, that explaining the mechanism of the phenomenon underlying this technique is still the matter of an intense and interesting debate. It is very possible that this lack of consensus contributes to the fact that SERS is yet to be successfully explained by quantum mechanics, and the theory used to explain it is still classical in nature.

In his article, Moskovits makes it clear that his favoured candidate to explain the enhancement mechanism is the plasmonic theory, which he explains clearly and succinctly. He then systematically examines the other popular theories, and provides arguments that in his view display the superiority of the plasmonic mechanism. He writes particularly strongly against the chemical enhancement theory, and urges its abandonment. Moskovits further suggests that the disagreements amongst SERS researchers may have resulted in opportunities to use the technique being missed due to uncertainty over its mechanism.

As research techniques undergo simultaneous development by multiple research groups, it is unsurprising that differences of opinion and opposing theories arise. If a particular view becomes popular, it can become so widely accepted that it is taken as fact and remains unchallenged for many years. It is therefore important that opposing views are presented, as in this article, in order that the relevant research community may consider their merits.

by Victoria Wilton

Form your own opinion – read the Perspective today:

Persistent misconceptions regarding SERS
Martin Moskovits
DOI: 10.1039/C2CP44030J