Mar
16
Scientists Double Hydrogen Water Electrolysis Efficiency
March 16, 2016 | Leave a Comment
Ruhr-Universitaet-Bochum researchers have boosted the efficiency of water electrolysis. They applied a layer of copper atoms to a conventional platinum electrode. Thus, reaction intermediates could desorb a bit more easily from the catalyst surface. The modified system generated twice the amount of hydrogen than a platinum electrode without a copper layer.
Together with his team, Wolfgang Schuhmann develops new electrodes, for instance for producing hydrogen. Image Credit: © Ruhr-Universitaet-Bochum, Tim Kramer. Click image for the largest view.
Water electrolysis has not yet established itself as an economical method for the production of hydrogen because too much energy is lost in the process. Now research has doubled the efficiency of the reaction.
In the journal researchers report in what way the efficiency of electrodes can be increased for the purpose of water electrolysis. Typically, platinum is applied as catalyst, in order to accelerate the conversion of water to hydrogen and oxygen. For the reaction to be as efficient as possible, intermediates must not adhere too strongly or too weakly at the catalyst surface.
The team headed by Prof Dr Aliaksandr Bandarenka from the Department of Physics of Energy Conversion and Storage in Munich and Prof Dr Wolfgang Schuhmann from the Center for Electrochemical Sciences in Bochum has calculated how strongly intermediates must adhere to the electrodes, in order to most efficiently facilitate the reaction. The analysis revealed that traditional electrodes from platinum, rhodium and palladium bind the intermediates a bit too strongly.
The researchers modified the properties of the platinum catalyst surface by applying a layer of copper atoms. With this additional layer, the system generated twice the amount of hydrogen than with a pure platinum electrode. But only if the researchers applied the copper layer directly under the top layer of the platinum atoms. The group observed another useful side effect: the copper layer extended the service life of the electrodes, for example by rendering them more corrosion-resistant.
Today only an estimated 4% of all hydrogen produced worldwide is the result of water electrolysis. As the electrodes used in the process are not efficient enough, large-scale application is not profitable.
Wolfgang Schuhmann said, “To date, hydrogen has been mainly obtained from fossil fuels, with large CO2 volumes being released in the process. If we succeeded in obtaining hydrogen by using electrolysis instead, it would be a huge step towards climate-friendly energy conversion. For this purpose, we could utilize surplus electricity, for example generated by wind power.”
Aliaksandr Bandarenka added, “In addition, the research on this reaction allows us to test, how well we can design catalyst surfaces by precisely positioning different metal atoms. A knowledge many other catalytic processes might benefit from.”
This research is significant because as more wind and solar electrical supplies come on line more power potential will be wasted. An easy dump to hydrogen production in an efficient competitive process would go far to assure more renewable electrical production gets built and on line. Now that the baseline is known more research and engineering can be applied to build even better electrolysis electrodes.
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