ChemCafé

Hydrogen occupies a central role in the field of renewable, green energies. It is however not a very convenient compound to work with, being highly flammable, gaseous above -253°C (at ambient pressure) – and therefore difficult to store and transport. Further, its energy density per volume is relatively low. Finding alternative ways to safely store and transport hydrogen represents an important challenge in this context.

A candidate of choice is formic acid: it is a small molecule, solid at ambient conditions, that can easily be converted to hydrogen (and carbon dioxide as a side-product). Alternatively, hydrogen (from renewable sources) and carbon dioxide can be combined to generate formic acid. However, the formation or decomposition of formic acid are not spontaneous, and catalysts are required in order for these reactions to proceed at useful rates.

In this context, a new catalyst was developed by Albert Boddien et al. from the Leibniz-Institut für Katalyse in Rostock, Germany, that can efficiently liberate hydrogen from formic acid. Importantly, the catalytic system, reported recently in Science, involved the use of an iron salt and a phosphine dissolved in propylene carbonate. The process is remarkable since it avoids the use of expensive, rare metals or highly toxic solvents – in addition to evolving hydrogen with high efficacy. Mechanistic investigations were performed based on nuclear magnetic resonance spectroscopy, kinetic studies, and density functional theory calculations to explain possible reaction mechanisms.

The catalytic cycle involving formic acid (HCOOH). The catalyst presented in the mentioned article is indicated here as 'catalyst B'.

This work represents an important step towards the use of formic acid as a safe, user-friendly surrogate for hydrogen in the frame of renewable energies.

Biocompatible polymers are avidely sought for owing to their frequent use in reconstructive sugery and as prostheses. One of the challenges is to make implants that are easy to inserate, minimizing scarring and recovery time.
A team led by Prof. Jennifer Helisseeff at Johns Hopkins University recently presented a novel implant, that can be injected as [...]

Sixteenth-century Swiss physician, botanist, alchemist, and astrologer Paracelsus* is widely known for his famous observation that “All things are poison, and nothing is without poison; only the dose permits something not to be poisonous”, generally summarized as “The dose makes the poison”.
No better illustration of the dual character of virtually any substance can be found [...]

DNA computing was first proposed in the mid-90s and uses chemical reactions to solve problems, using DNA strands as ‘bits’. The work recently published in Science by Lulu Qian and Erik Winfree from Caltech demonstrates the use of DNA for performing calculations (ie, finding the square roots of numbers up to 15). Made from 130 [...]

George Whitesides from Harvard University and John Deutch from MIT initiated the debate in a Comment published in the first 2011 issue of the journal Nature. In an issue mostly dedicated to chemistry (remember, 2011 is International Year of Chemistry), they advocate several changes chemical research in universities should undergo in order to “solve big [...]

During the second half of 2010 a term usually reserved to specialized audiences started to spread in mainstream media: the rare-earth elements. Although they are not so scarce as their name would suggest, increasing concerns about their availability in the near future were expressed, and a recent issue of Nature Materials featured several articles dedicated [...]

At a time when public expenses are shrinking, scientists are under close scrutinity and must justify the money they spend. Researchers are therefore increasingly exposed to the media, and it seems appropriate to ask whether they are ready for that. Two recent examples tend to show that they are not. The first is the clumsy [...]

Bisphenol A (BPA) is one of the world’s most widely manufactured chemicals and can be found virtually everywhere – it is present in many polymer plastics, food and drink containers, toys, computers, baby bottles, and medical equipment. BPA can easily leach from these products (e.g. in packaged food and drinks), and is therefore detectable in [...]

Famous hook-and-loop fastener Velcro was invented in the 50s by a swiss engineer, George de Mestral – it turns out he’s an alumnus of my own institution, the Ecole Polytechnique Fédérale de Lausanne. Velcro is made of two different sides, a hook and a loop side. When the two sides are pressed together, the [...]

Swiss people usually share a deep love for their mountains. So it is not such a surprise to see that researchers from IBM Research in Zurich, after having developed a new ‘nano-carving’ method, wanted to show it at work by sculpting a nanometric version of our most famous peak.
In a recent article in Science, Pires [...]