Environment: clean and safe hydrogen produced by electrolysis from alcohols

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Environment: clean and safe hydrogen produced by electrolysis from alcohols


Producing hydrogen in a clean, safe and efficient from solutions of alcohols renewable. It is the result reached by a team from the Institute of chemistry of organometallic compounds of the National Research Council (CNR-ICCOM) of Florence, directed by Francesco Vizza and shown on 'Nature Communications'.
"Commonly hydrogen is obtained from natural gas, a method that produces CO2 and therefore pollutes" says Vizza. "An alternative is to clean water electrolysis, a process that implies the decomposition of water into oxygen and hydrogen 'zero emission', but has a high energy consumption and, when produced in high pressure, presents safety problems since the mixing of the two elements can generate explosive mixtures. The novelty of our study is that we have developed an electrolyzer to produce hydrogen, but not oxygen, starting from aqueous solutions from renewable alcohols (ethanol, glycerol or other alcohols higher than extracts from biomass), obtaining an energy saving of 60 % compared to the electrolysis of water. As was known, in fact, to break water in the presence of alcohols it serves less energy than that required when there is only water, but none prior to our group had thought of exploiting these characteristics of the alcohol for the production of renewable hydrogen " .
Heart of the experiment are the nanostructured electrodes employed in an electrolytic cell of new generation. "It is anodic electrocatalysts consist of nanoparticles of palladium, deposited three-dimensional architecture of nano-titanium tubes", adds the researcher ICCOM-CNR, "thanks to which you can make electrolysers to produce hydrogen from aqueous solutions of alcohols derived from biomass, consuming 18.5 kWh for the production of 1 kg of hydrogen, compared to 45 kWh per 1 kg of hydrogen produced by water alone, a big gain energy and economic. The result far exceeds the recommendations of the DOE, the US Department of Energy that, by 2020, has set a limit of 43 kWh of electricity consumption per kg of hydrogen produced. "
Several potential technological implications of the research. "The clean hydrogen and low energy cost, suitably stored, could serve to generate electric current by some kWh up to higher powers: current generators portable and stationary, with zero environmental impact. Additionally, the electrolyzer of the invention allows to obtain, from renewable alcohols, compounds with high added value, useful in cosmetic and textile (derivatives of glycerol and ethylene glycol), food (acetate bioethanol) and production of biodegradable plastics (lactic acid from propanediol), which is currently only achieved by expensive and polluting industrial processes, "he concludes Vizza.
The research was funded by the European project and the project Decore Hydrolab2 Ente Cassa di Risparmio di Firenze, the two research units are coordinated respectively by Alessandro and Francesco Vizza Lavacchi.