New model explains interactions between small copper clusters used as low-cost catalysts in the production of hydrogen by breaking down water molecules

Copper nanoparticles dispersed in water or in the form of coatings have a range of promising applications, including lubrication, ink jet printing, as luminescent probes, exploiting their antimicrobial and antifungal activity, and in fuel cells. Another promising application is using copper as a catalyst to split water molecules and form molecular hydrogen in gaseous form.

At the heart of the reaction, copper-water complexes are synthesised in ultra-cold helium nanodroplets as part of the hydrogen production process, according to a recent paper published in EPJ D. For its authors, Stefan Raggl, from the University of Innsbruck, Austria, and colleagues, splitting water like this is a good way of avoiding splitting hairs.

Previous work showed that at the molecular level, water oxidises copper nanoparticles until their surface is saturated with molecules carrying hydrogen (called hydroxyl groups).

Theoretical work further showed that a monolayer of water, once adsorbed on the copper particles, spontaneously converts to a half-monolayer of hydroxide (OH) plus half a monolayer of water while releasing hydrogen gas.

In their study, Raggl and colleagues synthesised neutral copper-water complexes by successively doping helium nano-droplets - which are kept at the ultra-cold temperature of 0.37 K in a state referred to as superfluid - with copper atoms and water molecules.

These droplets are then ionised by electrons. The authors show that the composition of the most prominent ions depends on the partial copper and water pressures in the cell where the reaction occurs. They observe ions containing several copper atoms and several dozen water molecules.

The authors recognise that they failed to directly observe the predicted hydrogen formation because their instrument is not designed to detect electrically neutral entities.

References: S. Raggl, N. Gitzl, P. Martini, P. Scheier,O. Echt (2018), Helium nanodroplets doped with copper and water, Eur. Phys. Jour. D, DOI: 10.1140/epjd/e2018-90150-7

Related Links
Springer
Bio Fuel Technology and Application News

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

'Trash is gold' as Benin community turns waste into biogas
Houegbo, Benin (AFP) Aug 22, 2018
Garbage has never smelled so sweet for a small village in southern Benin since it opened a pilot waste treatment centre to turn household rubbish into gas - and cash. "Our trash has become gold. We no longer throw it into the bush. We use it to make money," beams Alphonse Ago, who lives next to the centre in Houegbo village. ReBin, a Swiss foundation for sustainable development, built the 1.3-hectare (3.2-acre) facility, which every week turns around six tonnes of organic waste into 200 cubic ... read more